Dissertations / Theses: 'Bombyci mori'

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Baggio, Mayarha Patricia Dequigiovanni. "Susceptibilidade do piloro de Bombyx mori (Lepidoptera, bombycidae) ao bombyx mori multiple nucleopolyhedrovirus." Universidade Estadual do Oeste do Parana, 2013. http://tede.unioeste.br:8080/tede/handle/tede/635.

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Made available in DSpace on 2017-07-10T14:17:04Z (GMT). No. of bitstreams: 1 Mayaha.pdf: 4416602 bytes, checksum: 8b663982eaff70076dc570733618b841 (MD5) Previous issue date: 2013-08-01 Bombyx mori multiple nucleopolyedrovirus (BmMNPV) is an entomopathogenic virus of the Baculoviridaefamily, genera Alphabaculovirus, which infects the silkworm (Bombyx Mori) and causes nuclear polyhedrosis disease. This virus is poliorganotrophic and a series of tissues are known as targets; however, literature does not present information in regards to the pylorus, segment of the hindgut, present in the transition with the midgut and responsible for regulating the passage of food towards the ileum. The organ is, thus, of fundamental importance in the ending of the digestive process, affecting the insect s metabolic balance and, the present study sought to analyze its susceptibility and cytopathology in regards to BmMNPV, geographic isolate of Paraná, Brazil. Moreover, due to the complexity of this segment, its general morphology will also be analyzed. In order to do so, hybrid B.mori caterpillars at 5º instar were inoculated experimentally with a viral suspension of BmMNPV. On different day post-inoculation (dpi), from 2º to 9ºdpi, segments of the intestine, containing the pylorus, with its subdivisions (posterior interstitial ring, pyloric cone and pyloric valve), were dissected, following the routine histological processing for paraffin wax blockage and dyes in haematoxylin and eosin, for general morphology analysis, and in modified Azan staining, for cytopathology. Segments also processed to form scanning electronic microscope for analized of morphological details. So the pylorus general morphology the caterpillars of B. mori, was similar to that observed in other insects. The cytopathology showed that the anterior area of the posterior interstitial ring is a secondary target of infection for the BmMNPV, after 5º dpi, and its infectious cycle is similar to that described in literature. In the hypertrophic nucleus one there the formation of viroplasm, place for production of enveloped nucleocapsids or virions, following the formation and development of the polyhedra. Later on, cytolysis occurred, promoting the liberation of polyhedra and the spreading of the disease, mainly in the B. mori creation sheds. The posterior area of the posterior interstitial ring, the pyloric cone and the pyloric valve did not reveal any traces of infection by BmMNPV and, thus, resistance mechanisms involving genetic factors could be acting. The knowledge obtained from this work will contribute in the establishment of the infectious cycle of this important entomopathogenic virus, which may lead to an epizootic that can negatively affect the whole productive chain of silk Bombyx mori multiple nucleopolyedrovirus (BmMNPV) é um vírus entomopatogênico da família Baculoviridae, gênero Alphabaculovirus, que infecta o bicho-da-seda (Bombyx mori) e causa a doença poliedrose nuclear. Este vírus é poliorganotrófico e uma série de tecidos são conhecidos como alvos; contudo, a literatura não apresenta informações sobre o piloro, segmento do intestino posterior, presente na transição com o médio e responsável pela regulação da passagem do alimento em direção ao ileo. O órgão é assim de fundamental importância na finalização do processo digestório, afetando o equilíbrio metabólico do inseto e, o presente estudo objetivou analisar sua susceptibilidade e citopatologia frente ao BmMNPV, isolado geográfico do Paraná, Brasil. Ainda, devido a complexidade deste segmento, também será analisada sua morfologia geral. Para tanto, lagartas híbridas de B. mori no 5° instar foram inoculadas experimentalmente com uma suspensão viral de BmMNPV. Em diferentes dias pós-inoculação (dpi), do 2° ao 9° dpi, segmentos do intestino, contendo o piloro, com suas subdivisões (anel intersticial posterior, cone pilórico e válvula pilórica), foram dissecados, seguindo o processamento histológico de rotina para emblocamento em parafina e colorações em hematoxina e eosina, na análise da morfologia geral, e em Azan modificado, para a citopatologia. Segmentos também foram processados em microscopia eletrônica de varredura para análise de detalhes morfológicos. Assim, a morfologia geral do piloro das lagartas da B. mori foi semelhante à observada em outros insetos. A citopatologia mostrou que a área anterior do anel intersticial posterior é alvo secundário de infecção pelo BmMNPV, a partir do 5° dpi, e seu ciclo infeccioso é semelhante ao descrito em literatura. No núcleo hipertrófico houve a formação do viroplasma, local de produção dos nucleocapsídeos envelopados ou virions, seguindo a formação e o desenvolvimento dos poliedros. Posteriormente, ocorreu a citólise, promovendo a liberação dos poliedros e disseminação da doença, principalmente nos barracões de criação de B. mori. A área posterior do anel intersticial posterior, o cone pilórico e a válvula pilórica não revelaram quaisquer indícios de infecção pelo BmMNPV e, desta forma, mecanismos de resistência envolvendo fatores genéticos poderiam estar atuando. Os conhecimentos obtidos irão contribuir no estabelecimento do ciclo infeccioso deste importante vírus entomopatogênico, cuja conseqüência de uma epizootia pode afetar negativamente toda a cadeia produtiva da seda

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Wang, Jian-Yang. "Interactions microsporidies-insectes in vivo : dissémination de Nosema bombycis (Microsporidia) dans son hôte Bombyx mori (Lepidoptera) et caractérisation de protéines structurales majeures de N. bombycis impliquées dans l'invasion." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2007. http://tel.archives-ouvertes.fr/tel-00717814.

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Nosema bombycis est un parasite obligatoire intracellulaire et eukaryoitique microsporidia apparenté aux champignons. Cette microsporidie est l'agent responsable de la pébrine, maladie du ver à soie Bombyx mori qui inflige de sévères pertes économiques à la sériciculture mondiale. Nous avons étudié l'interactions N. bombycis-B. mori in vivo : l'infestation par N. bombycis démarre au niveau de l'épithélium intestinal antérieur, puis s'étend aux muscles et trachées adjacents. Les tissus plus distants sont ensuite infectés. Cependant, les réponses immune mélanisation et phagocytose, l'hémolymphe et les hémocytes sont les vecteurs de la dissémination de N. bombycis dans son hôte. Nous avons développé une approche protéomique pour identifier des protéines de tube polaire (PTP). Trois PTPs ont été caracterisés par immunocytochimie MET et MS/MS. Des motifs de séquence peptidique ont pu en être déduits par les programmes Peaks Online et DeNovoX, puis évalués par algorithmes Mascot et Sequest

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Åberg, Gabriel. "Intrinsically Functionalized Silk (Bombyx Mori)." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97636.

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The goal of the thesis is to incorporate materials with either fluorescent or conductive properties in silk fibers, by feeding silkworms with a diet containing these materials. To achieve this, one would have to breed (rear) silkworm from eggs into larvaes, then to feed the silkworms with this special diet containing fluorescent or conductive materials. Samples of silk were then collected either from spun cocoons or via removing the silk producing organs (silk glands) from the silkworms via dissection. The samples were then analyzed with absorbance spectrometer, spectrofluorometer or via photoluminesecent measurement to determine if any materials had been incorporated into the silk fibers. Silkworms were successfully reared from eggs up to moths, once the silkworm larvae had grown enough in size their diet were switches from their regular food (silkworm chow) to food containing conjugated molecules or polymers with fluorescent or conductive properties. A total of 14 materials were tested. One material gave a clear positive result and that was from the fluorescent compound Rhodamine B. Other fluorescent materials, Nile red and POWT yielded some results indicating their presence in the silk but the results were not conclusive. The rest of the materials all failed with being incorporated within the silk fibers; this was due to their lethality, size, lack of zwitterionic properties and such. The properties of the materials are of great importance for the uptake process, where a small zwitterionic molecule has a great change of being taken up and incorporated in the silk fibers. Whereas a big materials such as a polymer without any zwitterionic will in most cases just follow through the food in the digestive track without any uptake.

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Trancik, Jessika. "Silk microstructures." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249173.

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Brady, Daniel. "Modulazione circadiana delle risposte immunitarie innate in Bombyx mori." Doctoral thesis, Università degli studi di Padova, 2022. http://hdl.handle.net/11577/3459359.

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The circadian clock is an internal timekeeping mechanism that enables organisms to physiologically anticipate and synchronise to daily changes in the environment such as shifting day light hours. The molecular mechanism of the clock is endogenously driven and rhythmically promotes and represses gene expression with a periodicity of around 24-hours. The clock regulates many biological functions and has been shown to modulate innate immune defences throughout the 24-hour day. In Drosophila, the immune response to several bacterial infections is regulated by the clock, and flies are more susceptible to systemic bacterial infections occurring in the day compared to at night. Oral ingestion is a more typical route of pathogenesis, though it is less well studied. We aimed to determine whether the immune response to an oral infection with Enterococcus mundtii in germ-free 1st day 5th instar (L5D1) Bombyx mori is regulated by the circadian clock or is modulated by light. We performed oral infections in B. mori reared in different photoperiods, including constant darkness. We found that larvae reared in 12:12 LD exhibited a time-of-day dependent variation in their immune responses, with larvae infected in the day (ZT3) more sensitive to the pathogen compared to night infected larvae (ZT15). When infected in DD, there was no difference in the survival response depending on the time of infection, indicating the immune response is not regulated by the circadian clock. We then characterised the 24-hour expression profiles of core clock and immune genes, circulating hemocytes and the structure of the midgut in germ-free L5D1 B. mori. The results indicate L5D1 B. mori lack a mature circadian oscillator, though several individual genes, including Clock (Clk), were cycling in 12:12 LD. Circulating hemocyte numbers vary in a cyclic fashion and are increased in the day but do not cycle in DD. We did not observe any daily variation in the midgut structure. A transcriptomic analysis of the midgut following oral infection identified distinct differential gene expressions following morning and night infections. Progenitors of hydrogen peroxide, juvenile hormone regulation, including ecdysone, and pathogen recognition receptors were rapidly upregulated 3 hours post infection at night. Moreover, antimicrobial peptides were activated 6 hours post night infection and a gene set enrichment analysis showed the Toll and imd pathway was activated 9 hours post a night infection. These immune modulators were not upregulated following a day-time infection. Although L5D1 B. mori lack a mature circadian clock, the Clk gene was rhythmically expressed in the brain and only in 12:12 LD. In a light-dependent manner, Clk regulates prothoracic hormone, that regulates ecdysone, that is an upstream activator Peptidoglycan Recognition Receptor-LC, a membrane bound pathogen sensor that activates the imd immune pathway. Therefore, even in the absence of a mature circadian clock the rhythmic expression of Clk in 12:12 LD and not DD, may be causing light driven modulation of innate immune responses that are not regulated by the circadian clock. We generated a period gene KO mutant and characterised the line for silk productivity, gene expression, egg hatching rhythm, daily hemocyte profile, daily variations in the midgut structure and performed an oral infection with E. mundtii in 12:12 LD. There was no difference in silk production compared to the wildtype, mutants lost hatching rhythmicity and per expression was considerably downregulated. Hemocytes fluctuated in the day but not in a circadian fashion. The per null line was more sensitive to oral infection with E. mundtii compared to the wildtype although the variation in survival depending on the time of infection was maintained with day-time infected larvae being more susceptible to the pathogen. The gut structure was unchanged thought the day but the peritrophic matrix was considerably compacted in the mutant. The circadian clock is an internal timekeeping mechanism that enables organisms to physiologically anticipate and synchronise to daily changes in the environment such as shifting day light hours. The molecular mechanism of the clock is endogenously driven and rhythmically promotes and represses gene expression with a periodicity of around 24-hours. The clock regulates many biological functions and has been shown to modulate innate immune defences throughout the 24-hour day. In Drosophila, the immune response to several bacterial infections is regulated by the clock, and flies are more susceptible to systemic bacterial infections occurring in the day compared to at night. Oral ingestion is a more typical route of pathogenesis, though it is less well studied. We aimed to determine whether the immune response to an oral infection with Enterococcus mundtii in germ-free 1st day 5th instar (L5D1) Bombyx mori is regulated by the circadian clock or is modulated by light. We performed oral infections in B. mori reared in different photoperiods, including constant darkness. We found that larvae reared in 12:12 LD exhibited a time-of-day dependent variation in their immune responses, with larvae infected in the day (ZT3) more sensitive to the pathogen compared to night infected larvae (ZT15). When infected in DD, there was no difference in the survival response depending on the time of infection, indicating the immune response is not regulated by the circadian clock. We then characterised the 24-hour expression profiles of core clock and immune genes, circulating hemocytes and the structure of the midgut in germ-free L5D1 B. mori. The results indicate L5D1 B. mori lack a mature circadian oscillator, though several individual genes, including Clock (Clk), were cycling in 12:12 LD. Circulating hemocyte numbers vary in a cyclic fashion and are increased in the day but do not cycle in DD. We did not observe any daily variation in the midgut structure. A transcriptomic analysis of the midgut following oral infection identified distinct differential gene expressions following morning and night infections. Progenitors of hydrogen peroxide, juvenile hormone regulation, including ecdysone, and pathogen recognition receptors were rapidly upregulated 3 hours post infection at night. Moreover, antimicrobial peptides were activated 6 hours post night infection and a gene set enrichment analysis showed the Toll and imd pathway was activated 9 hours post a night infection. These immune modulators were not upregulated following a day-time infection. Although L5D1 B. mori lack a mature circadian clock, the Clk gene was rhythmically expressed in the brain and only in 12:12 LD. In a light-dependent manner, Clk regulates prothoracic hormone, that regulates ecdysone, that is an upstream activator Peptidoglycan Recognition Receptor-LC, a membrane bound pathogen sensor that activates the imd immune pathway. Therefore, even in the absence of a mature circadian clock the rhythmic expression of Clk in 12:12 LD and not DD, may be causing light driven modulation of innate immune responses that are not regulated by the circadian clock. We generated a period gene KO mutant and characterised the line for silk productivity, gene expression, egg hatching rhythm, daily hemocyte profile, daily variations in the midgut structure and performed an oral infection with E. mundtii in 12:12 LD. There was no difference in silk production compared to the wildtype, mutants lost hatching rhythmicity and per expression was considerably downregulated. Hemocytes fluctuated in the day but not in a circadian fashion. The per null line was more sensitive to oral infection with E. mundtii compared to the wildtype although the variation in survival depending on the time of infection was maintained with day-time infected larvae being more susceptible to the pathogen. The gut structure was unchanged thought the day but the peritrophic matrix was considerably compacted in the mutant.

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Rao, P. Ram Tarak. "Genetic Architecture and gene action in bombyx mori l." Thesis, University of North Bengal, 1997. http://hdl.handle.net/123456789/1114.

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Grosse-Wilde, Ewald. "Rezeptoren und Bindeproteine für Pheromone von Bombyx mori: funktionelle Charakterisierung." Berlin Logos-Verl, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2844474&prov=M&dok_var=1&dok_ext=htm.

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Gil, Jr José. "Characterizing the 3D organization of holocentric chromosomes in Bombyx mori." Electronic Thesis or Diss., Université Paris sciences et lettres, 2022. http://www.theses.fr/2022UPSLS084.

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L'organisation du génome dans le noyau cellulaire a été observée et décrite dans différents organismes depuis plus de 140 ans. La plupart des organismes où cela a été fait sont monocentriques, c’est-à-dire dont les chromosomes n’ont qu’un seul centromère. Il a été montré que les centromères contraignent fortement l'architecture des chromosomes en interphase, et j'ai contribué lors de ma thèse à l’écriture d’une revue décrivant ce phénomène (Muller et al., 2019). Cependant, à travers l'Arbre de la Vie eucaryote, on peut trouver plusieurs exemples d'organismes qui sont holocentriques, c’est-à-dire qui ont plusieurs centromères distribués sur toute la longueur de leurs chromosomes. Pour étudier l'impact des centromères sur ce type de chromosomes, nous avons choisi comme organisme modèle le ver à soie, Bombyx mori. Bien que les chromosomes holocentriques de B. mori aient fait l'objet d'études décrivant l'organisation et la formation de leurs centromères et kinétochores (Cortes-Silva et al., 2020 ; Senaratne et al., 2021), l'organisation de leur génome reste à décrire. Ma thèse vise à caractériser l'organisation du génome de B. mori en utilisant des techniques basées sur le séquençage et des approches bioinformatiques sur deux systèmes expérimentaux.Dans la première partie de ma thèse, j'ai utilisé une combinaison de données Hi-C et ChIP-Seq d'embryons de B. mori pour identifier et caractériser les caractéristiques de l'organisation du génome. En utilisant les techniques Hi-C, j'ai produit des cartes de contact pour les 28 chromosomes de l'assemblage du génome de B. mori et j'ai pu montrer que les chromosomes de B. mori établissent des contacts peu fréquents entre eux, ce qui donne lieu à des territoires chromosomiques forts. J'ai ensuite combiné ces données Hi-C avec des ensembles de données ChIP-Seq correspondant à plusieurs marques épigénétiques de l'embryon de B. mori afin de définir et de caractériser les compartiments chromosomiques. Cette étude a révélé que les chromosomes de B. mori sont organisés en trois compartiments à l'échelle du génome : A, B et X. Les compartiments A et B de B. mori rappellent ceux décrits pour la première fois dans les chromosomes humains. Le compartiment X est composé de régions très compactes et pauvres en gènes qui n'interagissent ni avec les deux autres compartiments, ni avec des compartiments similaires sur le même chromosome. Ces résultats sont inclus dans une étude à laquelle j'ai participé et qui décrit l'organisation du génome des embryons de B. mori (Muller et al., en cours).Dans la deuxième partie de ma thèse, je me suis tourné vers les lignées cellulaires de B. mori afin de déterminer certains des facteurs contribuant à cette organisation du génome. Pour ce faire, j'ai utilisé l'ARN interférence pour perturber les centromères, les cohésines et les condensines, dont l'impact sur l'organisation du génome a été démontré chez d'autres organismes. J'ai acquis des données Hi-C, profilé différentes marques épigénétiques dans chaques conditions, et montré que les centromères et les complexes SMC jouent un rôle dans l'organisation du génome de B. mori, la cohésine et la condensine II ayant des effets opposés sur le repliement des chromosomes à courte et longue distance. Pour analyser correctement ces données, j'ai développé des outils bioinformatiques pour tenir compte de la nature holocentrique des chromosomes de B. mori. J'ai également eu l'occasion de mettre mes compétences en bioinformatiques au service d'une collaboration portant sur l'appariement méiotique des chromosomes de B. mori (Rosin et al., 2021). Ensemble, en utilisant Hi-C et ChIP-Seq et en effectuant l'analyse bioinformatique des deux, j'ai pu décrire pour la première fois l'organisation du génome de B. mori et caractériser les rôles des facteurs qui y contribuent The genome’s organization within the cell nucleus has been observed and described in various different organisms for over 140 years. Most of the organisms where this has been done are monocentric, or organisms that have chromosomes with a single centromere. Studies have shown that centromeres strongly constrain the architecture of chromosomes in interphase and during my thesis, I contributed to a review describing this phenomenon (Muller et al., 2019). However, across the eukaryotic tree of life you can find several examples of organisms that are holocentric, or organisms that have centromeres distributed along the entire length of their chromosomes. To study the impact of centromeres on these types of chromosomes, we choose the silkworm, Bombyx mori, as our model organism. Although the holocentric chromosomes of B. mori have been subjects of studies describing the organization and formation of their centromeres and kinetochores (Cortes-Silva et al., 2020; Senaratne et al., 2021), their genome organization has yet to be described. My thesis aims at characterizing the genome organization of B. mori with the use of sequencing-based techniques and bioinformatic approaches on two experimental systems.In the first part of my thesis I used a combination of Hi-C and ChIP-Seq data from B. mori embryos to identify and characterize genome organizational features. Using Hi-C, I produced contact maps for all 28 chromosomes of the B. mori genome assembly and I was able to show that B. mori chromosomes make infrequent contacts between themselves resulting in strong chromosome territories. I then combined this Hi-C data with ChIP-Seq data sets corresponding to several B. mori embryo epigenetic marks in order to define and characterize chromosome compartments. This study revealed that B. mori chromosomes are organized into three genome-wide compartments: A, B and X. The A and B compartments in B. mori are reminiscent of those first described in human chromosomes. The X compartment is composed of highly compact, gene-poor regions that do not interact with the other two compartments, nor with like compartments on the same chromosome. These findings are included in a study that I was a part of describing the genome organization of B. mori embryos (Muller et al., in progress).In the second part of my thesis I turned to B. mori cell lines in order to determine some of the factors contributing to this genome organization. In order to do this, I used RNAi to perturb centromeres, cohesins and condensins which have been shown to have an impact on genome organization in other organisms. I acquired Hi-C data and profiled different epigenetic marks in each condition and show that centromeres and SMC complexes play a role in B. mori genome organization with cohesin and condensin II having opposite effects in short- and long-range chromosome folding. To properly analyze this data, I developed bioinformatic tools to account for the holocentric nature of B. mori chromosomes. I even had the chance to contribute my bioinformatic skill set to a collaboration studying meiotic pairing of B. mori chromosomes (Rosin et al., 2021). Taken together, using Hi-C and ChIP-Seq and performing the bioinformatic analysis of both, I was able to describe for the first time the genome organization of B. mori and characterize the roles of factors contributing to it

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Wen, Shihao. "Design Of Multi-Drug Release Coaxial Electrospun Mat Targeting Infection And Inflammation." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1468852133.

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Zafar, M. S. "Developing silica based nanocomposites for dental applications using Bombyx mori silk." Thesis, Nottingham Trent University, 2011. http://irep.ntu.ac.uk/id/eprint/213/.

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A significant amount of research is being carried out on natural Bombyx mori (BM) silk which has gained remarkable popularity for biomedical applications in recent years. The main objective of this thesis is concerned with the development of a new silk based material with improved properties for dental tissue repair and dentin regeneration. In the first phase, research was carried out to study the chemistry and kinetics of silica formation and to assess the effects of silk proteins on the mechanical and functional properties of nanocomposite materials. A novel method was developed to separate different silk fractions (heavy chain fibroin and light chain fibroin) from natural silk using formic acid. Silk and its fractions were regenerated for use in gelation studies and fabricating nanocomposites by adding silica. The silica was added using, hydrolysed tetraethoxy silane (TEOS) to condense into gelling silk solutions or by adding pre-condensed silica nanoparticles (14-350 nm), prepared using a modified Stbber method. Silk solutions were characterised using viscometery, dynamic light scattering (DLS) and electrophoresis (SDS-PAGE). In the second phase, silk based nanocomposites were fabricated using electrospinning and gelation routes. The fabricated nanocomposite materials were characterised using scanning electron microscopy (SEM), elemental analysis (EDX), Fourier transform infra-red spectroscopy (FTIR), Thermogravimetric analysis (TGA) and compressibility testing. Both silk fractions (heavy chain fibroin and light chain fibroin) have entirely different structural, conformational and functional properties and can be regenerated using ionic solutions. Heavy chain silk due to its unique properties such as high hydrophobic amino acid domains (repeats of GAGAGS or GAGAGY) resulted in comparatively more p-sheet content, producing different solution as well as materials properties. Silk fractions were electrospun and the morphology of electrospun fibres was affected by the relative proportion of heavy and light chain silk in the solutions. Similar results were found for materials prepared by the gelation route. Addition of pre-condensed silica particles improved mechanical properties of composite materials compared to silica derived from TEOS. The development of novel methods of separating silk fractions will improve the availability of these fractions for future research and give a robust base for further studies in areas such as dental materials, biomaterials, biochemistry and biotechnology. Natural silk fractions and inorganic composites have a large potential for future applications in industry and research however a lot more research is required for their detailed characterisation and their interaction studies within the biological environment.

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Mangé, Alain. "Etude structurale et fonctionnelle des gènes d'actine cytoplasmique de Bombyx mori." Lyon 1, 1996. http://www.theses.fr/1996LYO10080.

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Dans la glande sericigene de bombyx mori, la majorite du pool cellulaire d'actine cytoplasmique est incluse dans des microfilaments apicaux impliques dans l'exocytose des proteines de la soie. Ces filaments sont desorganises de maniere cyclique au cours des mues larvaires, concomitamment avec l'arret de la synthese de la soie. Dans le cadre de ma these, j'ai entrepris l'analyse fonctionnelle du gene d'actine cytoplasmique a3 par des approches complementaires in vivo et in vitro. Deux sites aux fonctions antagonistes, ra3 et sre, modulent l'expression du gene de maniere negative pour l'element ra#3 et positive pour l'element sre. De facon interessante, ce dernier element est structurellement et fonctionnellement homologue a celui present en amont des genes d'actine cytoplasmique de vertebres. Les observations realisees in vitro et dans la chromatine, par footprinting in vivo, suggerent que l'element sre fixe un facteur proteique, dont les caracteristiques sont tres proches du facteur srf humain. Parallelement a cette etude, j'ai isole et caracterise le quatrieme gene d'actine de bombyx mori (a4). Ce dernier code une actine cytoplasmique tres homologue a celle codee par le gene a3. La comparaison de sa sequence codante a celles d'autres genes d'actine cytoplasmique d'insectes suggere que ces genes ont evolue a partir d'au moins un gene d'actine ancestral commun. Le gene a4 possede une organisation moleculaire complexe avec deux promoteurs distincts. L'ensemble de ces resultats souleve la question de l'importance biologique de chacune des isoformes d'actine cytoplasmique. L'etude fonctionnelle de leurs genes dans la glande sericigene devrait permettre d'aborder les fonctions multiples de la proteine dans la physiologie cellulaire

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Santorum, Marilucia. "Avaliação da toxicidade do inseticida novaluron em Bombyx mori (Lepidoptera Bombycidae) /." Botucatu, 2019. http://hdl.handle.net/11449/182490.

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Orientador: Daniela Carvalho dos Santos Resumo: O bicho-da-seda, Bombyx mori (Lepidoptera: Bombycidae), é o inseto de maior importância econômica na produção de seda. A lagarta se alimenta de folhas de amoreira e é altamente sensível a agrotóxicos, assim o uso destes em culturas agrícolas circunvizinhas às plantações de amoreira pode afetar o desenvolvimento de B. mori, acarretando em desequilíbrio nas suas funções metabólicas e, consequentemente, comprometendo a produção de casulos. Entre estes agrotóxicos, destaca-se o Novaluron, inseticida inibidor da síntese de quitina nos insetos e empregado no controle de insetos pragas de culturas agrícolas próximas as plantações de amoreira. Assim, investigamos os efeitos tóxicos de Novaluron no desenvolvimento de B. mori. Lagartas de B. mori, foram separadas em dois grupos experimentais: grupo controle (GC) e grupo tratamento (GT: tratado com 0, 15 mL/L de Novaluron). Após ecdise do 2° para o 3° instar, lagartas do GT foram alimentadas por 24 horas com folhas de amoreira tratadas com o inseticida. Paralelamente foi realizada uma nova exposição, porém em lagartas que realizavam a ecdise do 4° para o 5° instar. Lagartas, pupas e adultos de B. mori foram anestesiadas e segmentos do intestino médio, glândula da seda e órgãos reprodutores retirados e processados convencionalmente para técnicas de microscopias de luz, eletrônica e imunohistoquímica. Além disso, os efeitos no desenvolvimento, reprodução e qualidade do casulo também foram avaliados. O Novaluron provocou efeitos citotóxico... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: The silkworm, Bombyx mori (Lepidoptera: Bombycidae is the insect of major economic importance in the production of silk. The larvae feeds on mulberry leaves and is highly sensitive to agrochemicals, thus the use of these in agricultural crops surrounding the mulberry plantations can affect the development of B. mori, causing an imbalance in its metabolic functions and, consequently, compromising the production of cocoons. Among these agrochemicals, stands out the Novaluron, an insecticide inhibitor of the synthesis of chitin in insects and used in the control of insect pests of crops near mulberry plantations. Thus, we investigated the lethal and sublethal effects of Novaluron on the development of B. mori. Larvae were selected into two experimental groups: control group (CG) and treatment group (TG: treated with 0, 15 mL/L Novaluron). After ecdysis from the 2nd to the 3rd instar, the TG larvae were fed for 24 hours with mulberry leaves treated with the insecticide. In parallel, a new exposition was carried out, however in larvae that carry out the ecdysis from the 4th to the 5th instar. B. mori larvae, pupae and adults were anesthetized and segments of the midgut, silk gland and reproductive organs were removed and processed conventionally for light microscopy, electron microscopy and immunohistochemistry. In addition, the effects on the development, reproduction and quality of the cocoon were also evaluated. Novaluron caused cytotoxic effects on the midgut and the silk glan... (Complete abstract click electronic access below) Doutor

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Ray, Nilay. "Impact of qualitative differences of mulberry leaves on the performance of selected vivoltine races of Bombyx mori in the Terai of west Bengal." Thesis, University of North Bengal, 1999. http://hdl.handle.net/123456789/1094.

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Paul, Dulal Chandra. "Impact of dietary moisture on the performance of bombyx mori L. During Unfavourable Wet part of summer in West Bengal." Thesis, University of North Bengal, 1995. http://hdl.handle.net/123456789/1089.

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Madureira, Jéssica Vencatto Senem. "Citopatologia causada pelo Alphabaculovirus no sistema traqueal de Bombyx mori (Lepidóptera: Bombycidae)." Universidade Estadual do Oeste do Parana, 2014. http://tede.unioeste.br:8080/tede/handle/tede/658.

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Made available in DSpace on 2017-07-10T14:17:13Z (GMT). No. of bitstreams: 1 Dissertacao -16.pdf: 1891470 bytes, checksum: 1b28975beba2d1e4f43d3a0f9f79a9aa (MD5) Previous issue date: 2014-02-11 Bombyx mori is an insect of the order Lepidoptera that is only found only in germplasm banks; it is used in scientific research and for commercial purposes. In the latter case, the silk cocoon, which is produced at the end of the 5th larval instar, is used in the production of various yarns and fabrics. This branch of Brazilian agribusiness, known as sericulture, is well developed in the state of Paraná, where it is a form of small-scale family farming. Several factors impact negatively on Brazilian sericulture, such as diseases during rearing, and B. mori is susceptible to a virus from the Baculoviridae family, namely, Bombyx mori multiple nucleopolyhedrovirus (BmMNPV), genus Alphabaculovirus (AlphaBV), which infects the larvae and jeopardises commercial production of the cocoon, causing losses to farmers and industry. Studies have proved that BmMNPV is polyorganotropic and there are several target organs, such as the tracheal system; however, details of its cytopathology are not known. The tracheal system is responsible for the aeration of the tissues of the insect. Thus, the present study aimed to describe the cytopathology of the tracheas of hybrid larvae of B. Mori, infected experimentally with BmMNPV, and isolated geographically in the state of Paraná. Fifth instar hybrid larvae were divided into two groups; one control, and the other inoculated. After ingestion, and on different days post-inoculation (dpi), from the 2nd to the 9th dpi, the larvae were anesthetized and dissected. Segments of organs such as the integument, muscle and silk gland, containing branches of the trachea, were collected and fixed in Karnovsky modified for transmission electron microscopy. On the 2st dpi, fresh hemolymph analysis was conducted in order to determine the susceptibility of the hemocytes. The results revealed that the hemocytes were infected from the 2nd dpi and the epithelial cells of the trachea were infected from the 4th dpi. The cytopathology of the tracheal cells showed hypertrophic nucleus, containing the viroplasm, the site of the synthesis of the nucleocapsids. Subsequently, the formation and development of the polyhedra occured, accentuating the nuclear hypertrophy and culminating in cell lysis. Virions were also observed, immersed in the basal lamina of the trachea, which appeared to be disorganized. Thus, the cytopathology of the trachea was consistent with the infection caused by AlphaBV, and the data that was obtained provides a better understanding of the infectious cycle of BmMNPV in the body of the insect. The time of infection, later for the hemocytes, and the presence of virions in the basal lamina of the trachea, indicated that this system is a secondary target for infection, and also that the hemolymph is an important dispersant of viral infection Bombyx mori é um inseto da ordem Lepidoptera encontrado somente em bancos de germoplasma, sendo utilizado em pesquisas científicas e para fins comerciais. Neste caso, seu casulo de seda, construído ao final do 5º instar larval, é usado na produção de diversos fios e tecidos. Este ramo da agroindústria brasileira, conhecido como sericicultura, se apresenta bem desenvolvido no Estado do Paraná, estando incluído no programa de agricultura familiar. Vários são os fatores que exercem influência na sericicultura nacional, como as doenças, e B. mori é susceptível a um vírus da família Baculoviridae, o Bombyx mori multiple nucleopolyhedrovirus (BmMNPV), gênero Alphabaculovirus (AlphaBV). Ao infectar as lagartas o vírus compromete a produção comercial do casulo, causando prejuízos aos produtores rurais e a indústria. Estudos comprovam que o BmMNPV é poliorganotrófico e vários são os órgãos-alvos, como o sistema traqueal; entretanto, detalhes de sua citopatologia não são conhecidos. O sistema traqueal é responsável pela aeração dos tecidos do inseto e o presente estudo objetivou descrever a citopatologia das traqueias de lagartas híbridas de B. mori infectadas experimentalmente pelo BmMNPV, isolado geográfico do Paraná. Para tanto, lagartas híbridas de 5º instar foram divididas em dois grupos, controle e inoculado. Neste, o inóculo viral foi fornecido na alimentação e em diferentes dias pós-inoculação (dpi), do 2º ao 9º dpi, as lagartas foram anestesiadas e dissecadas; segmentos do tegumento, músculo e glândula da seda, contendo ramos da traqueia, foram coletados e fixados em Karnovsky modificado para a microscopia eletrônica de transmissão. No 2º dpi foi efetuada análise a fresco da hemolinfa, para averiguar a susceptibilidade dos hemócitos. Os resultados revelaram que os hemócitos se apresentaram infectados a partir do 2º dpi e as células epiteliais da traqueia a partir do 4° dpi. A citopatologia das células traqueais revelou núcleo hipertrófico, contendo o viroplasma, que é o local de síntese dos nucleocapsídeos. Posteriormente, houve a formação e o desenvolvimento dos poliedros, acentuando-se a hipertrofia nuclear e culminando com a citólise. Vírions também foram visualizados na lâmina basal da traqueia, que se apresentou desorganizada. Assim, a citopatologia da traqueia condiz com a infecção causada por AlphaBV, e as informações obtidas permitem um melhor entendimento do ciclo infeccioso do BmMNPV no corpo do inseto. O tempo de infecção, posterior ao dos hemócitos, e a presença de vírions na lâmina basal da traqueia, indicam que este sistema é alvo secundário e, ainda, que a hemolinfa se apresenta como um importante dispersor da infecção viral.

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Senaratne, Aruni Prabhashwari. "Formation of the CenH3-independent holocentromere in Lepidoptera avoids active chromatin." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS355.

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Malgré leur caractère essentiel pour une ségrégation fidèle des chromosomes, il existe diverses architectures de centromères parmi les eucaryotes représentés en deux principales configurations : mono- et holocentromères pour, respectivement une distribution localisée ou non localisée de l’activité centromérique. De précédentes études ont révélé que l’holocentrisme chez de nombreux insectes coïncide fortement avec la perte du marqueur centromérique – par ailleurs essentiel – CenH3 (CENP-A), suggérant un lien moléculaire entre les deux évènements. Nous avons exploité des éléments de centromères récemment identifiés ainsi que des approches génomiques pour cartographier et caractériser les centromères du vers à soie Bombyx mori, un insecte représentatif holocentrique dépourvu de CenH3. Cela a révélé une corrélation robuste entre les profils de centromères et les régions de faible dynamique de la chromatine trouvée n’importe où le long du chromosome. Des expériences de perturbation transcriptionnelle ont montré que les centromères sont exclus des régions actives de la chromatine, mais peuvent se former de novo dans les régions où l’activité de la chromatine est faible. Le lien identifié avec la chromatine aide à discuter de la plasticité de l’identité du centromère. Dans ce contexte, notre étude pointe vers un nouveau mécanisme de formation des centromères qui se produit de manière récessive sur le chromosome – large paysage chromatinien plutôt que d’être défini par la présence de CenH3. Sur la base de profils similaires observés chez d’autres lépidoptères, nous proposons un mécanisme conservé qui sous-tend l’établissement d’holocentromères par la perte d’un centromère précis Despite their essentiality for faithful chromosome segregation, centromere architectures are diverse among eukaryotes and embody two main configurations: mono- and holocentromeres, referring respectively to a localized or unrestricted distribution of centromeric activity. Previous studies revealed that holocentricity in many insects strongly coincides with the loss of the otherwise essential centromeric marker CenH3 (CENP-A), suggesting a molecular link between the two events. In this study, we leveraged recently- identified centromere components and genomics approaches to map and characterize the centromeres of the silk moth Bombyx mori, a holocentric insect representative lacking CenH3. This uncovered a robust correlation between centromere profiles and regions of low chromatin dynamics found anywhere along the chromosome. Transcriptional perturbation experiments showed that centromeres become excluded from active chromatin regions but can form de novo in regions where chromatin activity is low. The identified link to chromatin dynamics helps to discuss the plasticity of centromere identity. In this context, our study points to a novel mechanism of centromere formation that occurs in a manner recessive to the chromosome-wide chromatin landscape rather than being defined by the presence of CenH3. Based on similar profiles observed in additional Lepidoptera, we propose an evolutionarily conserved mechanism that underlies the establishment of holocentromeres through loss of a specified centromere

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Giacomin, Alessandra Maria. "Dinâmica da inovação da sericicultura no Brasil." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/100/100133/tde-14102018-180657/.

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O Brasil destaca-se como maior produtor de seda em escala comercial no Ocidente e o quinto maior no mundo, devido ao eficiente sistema integrado de produção, que qualifica os fios de seda brasileiros como de alta qualidade. A sericicultura é a criação do Bombyx mori L. (bicho-da-seda) para obtenção dos casulos de seda para a fiação. A atividade emprega, no Brasil, aproximadamente, 2.500 famílias no meio rural, gerando renda por cerca de 8 a 9 meses do ano, contribuindo para a fixação delas ao campo. Além disso, cerca de 2.000 funcionários trabalham nas empresas de fiação no meio urbano, e o total de empregos, contando com os empregos indiretos, associados à atividade, somam, aproximadamente, 20.000. Esta pesquisa teve como objetivo apresentar a dinâmica da inovação da sericicultura no Brasil e as medidas que vêm sendo tomadas nesse sentido. Os dados, para elaboração deste estudo, foram coletados por meio de análise bibliográfica, assim como, visitas técnicas às empresas e aos produtores ligados à sericicultura nos estados do Paraná e São Paulo. Foram realizadas entrevistas com quatro sericicultores, juntamente com representantes das empresas Fiação de Seda BRATAC S.A., Fiação de Seda Artesanal O Casulo Feliz, Instituto Vale da Seda e com Enéas Neto, estilista residente da marca Vale da Seda. As principais modernizações constatadas visam diminuir o esforço físico do trabalhador rural e aumentar a produtividade, mantendo os padrões de qualidade. Constatou-se, nas visitas e entrevistas aos produtores rurais, que a sericicultura é, na maioria dos casos, a principal fonte de renda familiar, afirmando a importância social e econômica da referida atividade e que, mesmo após anos anteriores de declínio, vem se mostrando promissora no Brasil, com aumentos gradativos nas últimas safras, tornando-se uma atividade bastante rentável. Por meio das entrevistas com os empresários e representantes do setor, relacionados com a produção de seda no Brasil, percebe-se que se sentem otimistas com relação ao futuro da seda, pois existe hoje uma maior preocupação com o uso de produtos provenientes de extração mais sustentável, duráveis e com maior valor agregado e, a seda, se enquadra nesses requisitos. Além disso, estudos preliminares indicam uma correlação positiva entre a produção de seda e a mitigação da Pegada de Carbono. Desse modo, a sericicultura, de forma sustentável, ética e socialmente responsável, poderá apresentar cada vez maior destaque e, por consequência, refletir positivamente na economia brasileira como um todo. Conclui-se que a sericicultura é uma atividade economicamente viável para o Brasil, o qual apresenta condições de solo e clima favoráveis para a criação do bicho-da-seda, em diversas regiões de seu território, com a possibilidade de gerar empregos e renda, tanto na área rural, quanto na urbana. Impulsionada pela mecanização e modernização da atividade agropecuária, a sericicultura nacional vem retomando lugar de destaque Brazil stands out as the largest commercial scale silk producer in the West and the fifth largest in the world due to its efficient integrated production system, which qualifies Brazilian silk yarns as high quality. The sericulture is the creation of Bombyx mori L. (silkworm) to obtain silk cocoons for spinning. The activity employs approximately 2,500 rural families in Brazil, generating income for about 8 to 9 months of the year, contributing to their setting in the field. In addition, around 2,000 employees work in the spinning companies and the total amount of jobs, added to the indirect jobs by the activity, is, approximately, 20,000. This research aimed to present the dynamic of sericulture innovation in Brazil and the measures that have been taken in this direction. All the data for the preparation of this study were collected through bibliographic analysis, as well as technical visits to companies and producers linked to sericulture in the states of Parana and Sao Paulo. Interviews were conducted with four sericulturists, along with representatives of the spinning companies of Silk BRATAC S.A., spinning of handmade silk O Casulo Feliz, Silk Valley Institute and with Eneas Neto, resident designer of the Silk Valley brand. The main modernizations observed aim to reduce the physical effort of the rural worker and increase productivity, maintaining the renowned Brazilian quality standards. In the visits and interviews with rural producers, sericulture is, in most cases, the main source of income of the family, affirming the social and economic importance of this activity, and that, even after previous years of decline, showing promising in Brazil, with gradual increases in the last harvests, becoming a very profitable activity for producers of other crops. Through interviews with businessmen and industry representatives related to the production of silk in Brazil, it is perceived that they feel optimistic about the future of silk, as there is a greater concern with the use of products from more sustainable extraction, durable and with higher added value, and silk meets these requirements. Furthermore, preliminary studies indicate a positive correlation between silk production and Carbon Footprint mitigation. In this way, sericulture, in a sustainable, ethical and socially responsible manner, may be increasingly prominent, and consequently, positively reflecting on the Brazilian economy as a whole. It is concluded that sericulture is an economically viable activity for Brazil that presents favorable soil and climate conditions for the creation of silkworms, as well as generates jobs and income in the rural area, contributing to a decrease in the rural exodus. Driven by the mechanization and modernization of agricultural activity, the national sericulture has resumed a prominent place

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Hu, Yupeng. "ELECTROSPUN NANOFIBERS FOR PROGRAMMABLE DRUG DELIVERY SYSTEM SEQUENTIALLY TARGETING INFLAMMATION AND INFECTION." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1436835377.

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Ayutsede, Jonathan Eyitouyo Ko Frank K. "Regeneration of bombyx mori silk nanofibers and nanocomposite fibrils by the electrospinning process /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/546.

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Simons, Pamela J. "Molecular evolution of the alpha-amylase genes of Bombyx mori and other insects." Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/6643.

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The gene of the ubiquitous starch degrading enzyme $\alpha$-amylase has been chosen to study evolutionary mechanisms and the relationships between several insect groups. In this project, the $\alpha$-amylase gene sequence of a representative of the order Lepidoptera, Bombyx mori, was determined. The coding region of Bombyx and the seven other insect genes are approximately the same size and have at least 60% identity with one another. There are various numbers of introns dispersed throughout the loci but often sites are shared between two or more species. There is evidence of differing codon biases among the genes with Drosophila and Anopheles being very GC rich and Choristoneura and Tribolium having virtually no bias. Biases caused discrepancies between the phylogenetic trees created by several different methods. Representatives of the same order always grouped together as predicted, but the order within the Lepidoptera varied with the method used. (Abstract shortened by UMI.)

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saviane, alessio. "Selezione di razze di Bombyx mori ad alta efficienza nutrizionale e relative problematiche." Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3424034.

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The silkworm (Bombyx mori L.) is an insect belonging to the lepidopteran order, family Bombycidae: it is one of the two unique species belonging to the genus Bombyx, together with its ancestor – Bombyx mandarina Moore. In the past, silkworm exploitation in Europe was particularly related to the agricultural sector and the production of the silk thread but this type of activity has being disappearing from the old continent, in favour of some Asian countries, especially China, where cost of labour is low. In spite of the decline of these traditional activities the silkworm started to be used as a tool in a lot of technological applications and as a model in scientific research in various fields. Silk is regarded as a promising biomaterial because of its physical and chemical features both on the macro and microscale as well as in nano-technologies. Furthermore biology and biotechnology are interested in silkworm, or in its cell cultures, as a bioreactor to produce recombinant proteins which should otherwise be produced in bacteria or yeasts. The silkworm has a suitable size even for complex experiments with respect to other organisms used for the same aims, however it does not require large rearing rooms or high quantity of food, it can be easily reared under controlled conditions and its biological cycle is short (it lasts about 45 days), representing thus, also a model for basic research in life sciences. Moreover, to use the silkworm as a technological platform, important steps were achieved by sequencing the whole genome and by developing new optimized artificial diets for this insect (strictly monophagous), which freed rearing from seasonal constraints coming from mulberry leaf production in temperate climates. Thus, the above-mentioned new potentialities and a revived interest from the textile industry, about a silk supply chain outside Asia, establish the background of the research work described in this thesis. In fact, performed experiments relate with relaunching basic research activities about B. mori and aimed at meeting the needs of a silk industry, possibly developing in temperate countries. The starting material, that is the B. mori strains, belongs to the germplasm collection of Consiglio per la Ricerca e la sperimentazione in Agricoltura – Unità di ricerca di Apicoltura e Bachicoltura (CRA-API) of Padua and consists of about 200 strains, which differ in their phenotypic and genotypic characteristics. From the aforementioned collection, a selection process based on a mixed rearing strategy on both mulberry leaves and artificial diet has been started. The final goal was to select new strains characterized by high nutritional efficiency in order to optimize the cost-benefit ratio in all those application oriented to productivity. As already stated selection was based on a mixed approach: the first and more traditional step consisted in rearing silkworm larvae on mulberry leaf without any limitation in its quantity, by selecting only for the most important commercial parameters. On the other hand, the second step was a rearing cycle on artificial diet with a limited food amount fed to fifth instar larvae, followed by a selection process according to the most important productive traits. After three years and six generations of selection and genetic improvement, the obtained strains were compared among each other and with the unselected populations on the base of nutritional indexes which permitted an assessment of their conversion efficiency of proteins contained in the food matrix to body mass and silk. The final evaluation allowed to highlight the efficacy of the adopted strategy in selecting the desired features, although a difference related to diverse adaptability of the strains to the diet was recorded. In particular, for some of them, an additional preparatory step of selection on diet appears to be appropriate. During the period when experiments aimed at selection of highly efficient strains were performed, other relevant experimental data were produced. First of all, a new micro-organism which proved itself to be pathogenic for the silkworm reared on artificial diet was isolated and characterized; then, in-depth measurements about cold hardiness of eggs of a polyvoltine silkworm strain belonging to CRA-API’s collection were carried out. Described results to date do not represent the final goal but, an intermediate stage of a selection process that will continue at CRA-API and also, the starting point for the production of new hybrids with improved performances and suited to be reared on both mulberry leaf and artificialdiet. Il baco da seta (Bombyx mori L.) è un insetto appartenente all’ordine dei lepidotteri, famiglia Bombycidae; è una delle due uniche specie rappresentanti il genere Bombyx, assieme a Bombyx mandarina M., suo progenitore ancestrale. In passato, in Europa, il suo utilizzo era legato soprattutto al mondo agricolo ed alla produzione della fibra serica ma questo tipo di attività è andata scomparendo dal vecchio continente, a favore di alcuni Paesi asiatici, fra cui soprattutto la Cina, con basso costo della manodopera. A dispetto del declino di questo tipo di attività tradizionali, il baco da seta ha però cominciato ad essere utilizzato per applicazioni tecnologiche di alto profilo legate al mondo della ricerca scientifica e della bio-industria. Si sono indagati, da un lato, utilizzi che impiegano la seta come biomateriale e che mirano allo sfruttamento delle sue proprietà fisiche e chimiche sia su scala macroscopica sia su scala microscopica come nel campo delle nanotecnologie. Dall’altro lato, le scienze biologiche e le biotecnologie sono in grado di utilizzare l’insetto stesso, oppure colture cellulari da esso derivate come bio-fabbriche per la produzione di proteine altrimenti sintetizzate in batteri o lieviti. Poiché il baco da seta, rispetto ad altri organismi utilizzati per gli stessi scopi, è di dimensioni adeguate a sperimentazioni anche complesse, pur non richiedendo ampi spazi d’allevamento o elevate quantità di cibo, come ad esempio gli animali superiori, è facilmente allevabile in laboratorio e possiede un ciclo biologico breve (circa 45 giorni), rappresenta un ottimo modello per la ricerca di base nei campi delle scienze della vita. In tal senso, per rendere il B. mori un’appetibile piattaforma tecnologica, importanti passi avanti sono stati fatti con il sequenziamento del genoma e con la formulazione di diete artificiali in grado di svincolare l’allevamento dell’insetto, strettamente monofago, dalla produzione della foglia di gelso, reperibile solo stagionalmente nelle regioni a clima temperato. Sullo sfondo di queste potenzialità tecnologiche e anche in relazione ad un rinato interesse da parte dell’industria del settore serico per una filiera produttiva extra-asiatica, va inquadrato il lavoro di ricerca presentato nella seguente tesi. La sperimentazione descritta è, infatti, inquadrabile in una più generale attività di rilancio della ricerca di base riguardante il baco da seta ed in sintonia con le necessità di un potenziale settore produttivo localizzato in paesi climaticamente simili all’Italia. Il materiale di partenza, ossia le razze di B. mori, appartengono infatti alla banca di germoplasma del Consiglio per la Ricerca e la sperimentazione in Agricoltura – Unità di ricerca di Apicoltura e Bachicoltura (CRA-API) di Padova; la collezione di accessioni è composta da circa 200 razze distinguibili sulla base di diverse caratteristiche fenotipiche e genotipiche. Partendo dalla suddetta collezione, è stato compiuto un lavoro di selezione basato su una strategia di allevamento misto dieta-foglia finalizzato alla selezione di razze, caratterizzate da un’elevata efficienza alimentare sia su foglia di gelso sia su dieta sostitutiva, in modo da ottimizzare il rapporto costi/benefici in tutti quegli ambiti interessati ad aspetti di produttività. Come sopra ricordato, la strategia era basata su un approccio misto: un primo step, più tradizionale e orientato all’incremento dei parametri produttivi della seta in senso classico, era incentrato sull’allevamento con foglia, fornita senza limitazioni di quantità. Un secondo step prevedeva, invece, un ciclo d’allevamento su una dieta sostitutiva della foglia di gelso in cui la selezione per la produttività avveniva a fronte di un’alimentazione contingentata. Dopo tre anni in cui si sono svolte sei generazioni di selezione, le popolazioni originali sono state confrontate sia tra loro sia con le selezioni ottenute; per tale comparazione, sono stati utilizzati indici alimentari in grado di qualificare le larve secondo la loro efficienza nel convertire le proteine contenute nella matrice alimentare in massa corporea e seta. La valutazione finale ci ha permesso di evidenziare come la strategia adottata, si sia rivelata efficace nel permettere la selezione dei caratteri desiderati sebbene, alcune differenze legate alla diversa adattabilità delle varie razze alla dieta artificiale, suggeriscano l’utilità dell’introduzione di una selezione preliminare per questo carattere. Nell’ambito della sperimentazione finalizzata alla selezione delle razze ad alta efficienza sono stati condotti alcuni esperimenti complementari che hanno portato alla produzione di rilevanti dati scientifici. In primo luogo è stato isolato e caratterizzato un microorganismo, dimostratosi patogeno per il baco da seta allevato su dieta artificiale ed, in secondo luogo, sono state effettuate approfondite misurazioni sulla resistenza alle basse temperature da parte di uova di una razza polivoltina appartenente alla collezione del CRA-API. I risultati esposti nel presente lavoro rappresentano, allo stato attuale, non un punto d’arrivo ma la tappa intermedia di un processo di selezione che verrà proseguito presso CRA-API oltre che la base di partenza per la produzione di nuovi ibridi dalle prestazioni migliorate ed allevabili, indifferentemente, su foglia e dieta sostitutiva con buone performances.

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22

Fayard, Chantal. "Mises au point de la transgenèse chez le ver à soie Bombyx mori L et perspectives d'applications." Lyon 1, 2001. http://www.theses.fr/2001LYO10273.

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La transgenèse est une méthode puissante pour étudier la fonction de gènes ou pour conférer des traits génétiques utiles à des organismes. Au cours de ma thèse, j'ai testé l'aptitude du transposon piggyBac (découvert chez le lépidoptère Trichoplusia ni) à intégrer des gènes dans les chromosomes de cellules d'insectes en culture. J'ai ensuite appliqué ce système à l'intégration stable et transmissible à la descendance d'un gène d'intérêt dans le génome du ver à soie Bombyx mori L. Ce système utilise deux vecteurs; l'un véhicule un gène d'intérêt (le gène rapporteur gfp sous le contrôle du promoteur du gène de l'actine cytoplasmique BmA3) placé entre les extrémités inversées répétées de l'éléments piggyBac ; l'autre est un vecteur assistant non-autonome qui code la transposase de piggyBac sous le contrôle du même promoteur. La co-injection des deux vecteurs dans l'œuf au stade préblastodermique aboutit à la transformation de gamètes chez environ 2% des individus injectés. L'analyse de l'ADN génomique des larves transgéniques a révélé que l'expression de la fluorescence résultait d'insertions souvent multiples du transgène ; celui-ci est par ailleurs hérité de façon mendélienne au cours des générations. J'ai donc pu montrer que ce système est efficace pour la transformation germinale du ver à soie. J'ai donc pu montrer que ce système est efficace pour la transformation germinale du ver à soie. J'ai entrepris d'exploiter la transgenèse pour inhiber par interférence d'ARN l'expression de gènes fortement exprimés dans la glande séricigène. L'application au gène codant la Fibroine, la protéine majoritaire de la soie, si elle est réalisable, permettrait de substituer cette protéine par des protéines d'intérêt textile et pharmaceutique.

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Gupta, Maneesh Kumar. "FABRICATION AND TESTING OF SCAFFOLDS FOR CELL GROWTH FROM IONIC LIQUID SOLUBILIZED FIBROIN." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1197670563.

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24

Banerjee, Kamalendu. "Reproductive performance and cocoon charecters of Bombyx mori L. with reference to regulated feeding and treatments with methoprene and imidazole compounds." Thesis, University of North Bengal, 1998. http://hdl.handle.net/123456789/1092.

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25

Lee, Donghan. "NMR studies on the structure and function of the Bombyx mori pheromone-binding protein /." [S.l.] : [s.n.], 2003. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=15263.

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26

Begum, Hosne Ara. "Hybridization of mulberry silkworm (Bombyx Mori L.) for higher silk productivity and disease resistance /." [St. Lucia, Qld.], 2006. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19789.pdf.

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27

Krasnov, Igor [Verfasser]. "Mechanical properties of Bombyx mori silkworm silk: viscoelasticity, structural and molecular origin / Igor Krasnov." Kiel : Universitätsbibliothek Kiel, 2013. http://d-nb.info/1045604046/34.

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28

Santorum, Marilucia. "Infecção de células da ampola dos túbulos de MALPIGHI de Bombyx Mori pelo Alphabaculovirus." Universidade Estadual do Oeste do Parana, 2015. http://tede.unioeste.br:8080/tede/handle/tede/650.

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Made available in DSpace on 2017-07-10T14:17:10Z (GMT). No. of bitstreams: 1 AMPOLA DOS _ MALPIGHI DE Bombyx mori PELO ALPHABACULOVIRUS.pdf: 2176663 bytes, checksum: 866566cf54573cb621db0597bbb30516 (MD5) Previous issue date: 2015-02-24 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Bombyx mori nucleopolyhedrovirus (BmNPV) is an entomopathogenic virus Baculoviridae family, Alphabaculovirus genre, which infects the silkworm, Bombyx mori and causes nuclear polyhedrosis disease. A viral geographic isolated from BmNPV was identified in the state of Paraná, Brazil, and a number of organs and target tissues were identified, but there is no information about the infection of Malpighian tubules (MT). MT make up the excretory system of B. mori, acting in the elimination of toxic substances and electrolyte homeostasis. This study aimed to analyze the behavior on the susceptibility and cytopathology of MT B. mori to BmNPV. Therefore, hybrid B.mori caterpillars at 5º instar, were inoculated experimentally with a viral suspension of BmNPV. On different days post-inoculation (dpi), the 4° to 9° dpi, MT segments were collected, divided in regions of the ampullae, proximal, medial and distal; following the processing for light and electron microscopy transmission. Material control followed the same process that the inoculated. The results showed that B. mori MT showed variations in their morphology and susceptibility to BmNPV according to the analyzed region. Thus, the region of the ampullae in its transition area to the proximal, appeared susceptible to BmNPV, from 6° dpi, while other regions showed no evidence of infection by the pathogen. The transition area is a small region which is located at the end of the ampullae and the beginning of the proximal region of MT. The cellular morphology of simple lining epithelium showed continuous variation of pavement, characteristic of the ampullae, the cylindrical, in the transition area; already continuous with the proximal region of MT, this morphological change was abruptly. The cytopathology revealed in hypertrophic nucleus, viroplasm containing the nucleocapsid and viral polyhedra. At the end of the infectious cycle was observed cytolysis of infected cells, releasing polyhedra in the extracellular medium, both in hemocele as in MT lumen, a factor that may favor the transmission of the disease. Thus, infection of the ampullae in its transition area to the proximal region, will contribute to greater scientific knowledge of cytopathology aspects and targets of infection from this virus isolated geographical, for the establishment of its infectious cycle of the insect's body BmNPV Bombyx mori nucleopolyhedrovirus (BmNPV) é um vírus entomopatogênico da família Baculoviridae, gênero Alphabaculovirus, que infecta o bicho-da-seda, Bombyx mori (Lepidoptera: Bombycidae) e causa a doença poliedrose nuclear. Um isolado geográfico viral do BmNPV foi identificado no estado do Paraná, Brasil, e uma série de órgãos e tecidos alvos foram identificados, porém não há informações sobre a infecção dos túbulos de Malpighi (TM). Os TM compõem o sistema excretor de B. mori, atuando na eliminação de substâncias tóxicas e na homeostase hidroeletrolítica. Assim, este estudo objetivou analisar o comportamento referente à susceptibilidade e citopatologia dos TM de B. mori ao BmNPV. Para tanto, lagartas híbridas de B. mori, 5° instar, foram inoculadas experimentalmente com uma suspensão viral de BmNPV. Em diferentes dias pós-inoculação (dpi), do 4° ao 9° dpi, segmentos dos TM foram coletados, subdivididos nas regiões da ampola, proximal, média e distal; seguindo o processamento para as microscopias de luz e eletrônica de transmissão. Material controle seguiu o mesmo processamento que o inoculado. Os resultados demonstraram que os TM de B. mori, apresentaram variação na sua morfologia e susceptibilidade ao BmNPV de acordo com a região analisada. Assim, a região da ampola, na sua área de transição com a proximal, se apresentou susceptível ao BmNPV, a partir do 6° dpi, enquanto as demais regiões não evidenciaram indícios de infecção pelo patógeno. A área de transição é uma pequena região que se localiza ao término da ampola e inicio da região proximal do TM. A morfologia celular do epitélio de revestimento simples apresentou variação continua de pavimentoso, característico da ampola, a cilíndrico, na sua área de transição; já na continuidade com a região proximal do TM, esta variação morfológica foi abrupta. A citopatologia revelou no núcleo hipertrófico, o viroplasma, contendo os nucleocapsídeos e os poliedros virais. Ao final do ciclo infeccioso foi verificado a citólise de células infectadas, liberando poliedros no meio extracelular, tanto na hemocele como no lúmen do TM, fator que pode favorecer a transmissão da doença. Assim, a infecção da ampola, na sua área de transição com a região proximal, irá contribuir com um maior conhecimento científico dos aspectos citopatológicos e dos alvos de infecção deste isolado geográfico viral, visando o estabelecimento do seu ciclo infeccioso do BmNPV no corpo do inseto.

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29

Mounier, Nicole. "Étude de la structure et de l'expression de trois gènes d'actine chez Bombyx mori." Lyon 1, 1991. http://www.theses.fr/1991LYO19011.

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Trois gènes d'actine ont été isoles d'une banque génomique et leur région codante a été séquencée. L'étude de leur expression pendant le développement a montré que deux d'entre eux codent pour des actines musculaires et que le troisième est un gène d'actine cytoplasmique. Les actines musculaires d'insectes sont des protéines très voisines qui ont significativement divergé des actines cytoplasmiques des invertébrés et des vertèbres. L'expression du gène d'actine cytoplasmique a été analysée dans la glande séricigène en relation avec le cycle de production de la soie. L'accumulation de ses ARNM est étroitement liée à l'alternance mue inter-mue. Ce gène a été transféré dans la lignée germinale de la drosophile et est transcrit dans les lignées transgéniques

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30

Meneguim, Ana Maria. "Qualidade nutricional de cultivares de amoreira (Morus spp.) para Bombyx mori L. (Lepdoptera : Bombycidae)." Universidade Estadual de Londrina. Centro de Ciências Agrárias. Programa de Pós-Graduação em Agronomia, 2008. http://www.bibliotecadigital.uel.br/document/?code=vtls000135552.

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O crescimento da sericicultura paranaense depende, entre outros fatores, da maior rentabilidade da atividade, tanto em nível do produtor como das indústrias de fiação. Maior produtividade, aliada à qualidade tecnológica do casulo, pode ser alcançada através da exploração de cultivares com maior produção de massa foliar e nutricionalmente superiores a cultivar padrão Miura, que atualmente, está plantada em mais de 80% da área sericícola do Estado. Visando obter informações para identificar cultivares alternativas à ?Miura?, foram conduzidos estudos no Instituto Agronômico do Paraná, IAPAR, Londrina para caracterizar quimicamente e bromatologicamente as cultivares de amoreira Miura, Korin, Tailandesa, FM 3/3, FM 86, SK 1 e SK 4. Os efeitos destas cultivares sobre a nutrição quantitativa, o desenvolvimento, a produção e qualidade tecnológica de casulos também foram determinados. Os tratamentos foram repetidos quatro vezes no delineamento de blocos ao acaso no experimento da criação e análise tecnológica dos casulos, e no delineamento inteiramente casualizado para as análises da nutrição quantitativa e da caracterização química e bromatológica. As cultivares apresentaram diferenças significativas em relação à composição química e bromatológica das folhas e influenciaram significativamente os parâmetros da nutrição quantitativa, da criação e da produção e qualidade tecnológica de casulo do bicho-da-seda. Duas cultivares (FM 3/3 e SK 4) foram identificadas como superiores, pois afetaram favoravelmente o desenvolvimento das lagartas e, influenciaram as características comerciais do casulo, proporcionando incrementos importantes na produção. Para maioria dos parâmetros tecnológicos do casulo, essas cultivares proporcionaram resultados iguais ou superiores a ?Miura?, porém quanto aos índices da nutrição quantitativa de consumo e de utilização do alimento por lagartas de B. mori o híbrido SK 4 foi o mais adequado. A análise conjunta, considerando o maior teor de nutrientes das folhas e melhor adequação nutricional juntamente com a produção e qualidade tecnológica de casulos, indica que entre as cultivares de amoreira, alternativas à variedade padrão Miura, o híbrido ?SK 4? é a cultivar mais favorável para ser utilizada na exploração sericícola paranaense. Sericulture expansion in the State of Paraná depends, among other factors, on the higher rentability for the farmer and for the silk reeling industries. Higher productivity allied to cocoon technological quality may be achieved by exploiting cultivars with high foliar mass production and nutritionally superiors to the standard cultivar Miura that is presently planted in more than 80% of the siriciculture area in the State. Aiming to obtain information to identify alternative cultivars to ?Miura?, studies were carried out at the Instituto Agronomico do Parana, in Londrina, PR, to characterize chemically and bromatologically the mulberry cultivars Miura, Korin, Tailandesa, FM 3/3, FM 86, SK 1 e SK 4. The effects of these cultivars on quantitative nutrition, development, production and technological quality of cocoons were also determined. Treatments were replicated four times in a randomized block design in the rearing and technological analysis of the cocoons experiment, and in a completely randomized block design for qualitative nutrition and chemical and bromatological characterization analysis. Significant differences were found among cultivars tested in relation to chemical and bromatological composition of the leaves and qualitative nutrition parameters, rearing and production and technological quality of the silkworm. Two cultivars (FM 3/3 and SK 4) were identified as superiors as they favorably affected larvae development and, in general, influenced the commercial cocoon characteristics, thus resulting in increments in production. In he majority of the cocoon technological parameters these cultivars were similar or superior to ?Miura?, however, when the qualitative nutritional consumption index and silkworm food utilization was considered, the hybrid SK 4 was the most adequate. The joint analysis considering the positive results obtained in relation to mulberry leaf quality, quantitative nutrition and technological quality of cocoons indicates that among the alternatives to the Miura variety, the hybrid SK 4 is the most favorable cultivar to be used in the exploitation of sericiculture in the State of Paraná.

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31

Hachouf, Saliha. "Caractérisation et identification de 2 ADNc exprimés lors de la morphogenèse alaire chez Bombyx mori : BmSP1 et alpha tubuline." Lyon 1, 1997. http://www.theses.fr/1997LYO10194.

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Chez les insectes holometaboles, les disques imaginaux sont des ebauches ectodermirques formees chez l'embryon. Au cours des developpements embryonnaire et larvaire, le disque s'accroit et se compartimente en territoires morphogenetiques par l'expression de genes de developpement. Il se differencie en organe adulte au cours de la phase de metamorphose dont le declenchement est controle par l'hormone de mue et l'hormone juvenile. Le but du present travail est de comprendre comment sont regulees et coordonnees les etapes de la morphogenese de l'aile nymphale ; l'analyse a ete entreprise sur le lepidoptere bombyx mori. La voie d'approche est l'analyse du fonctionnement de genes exprimes lors de cette morphogenese. Deux clones adnc ont ete isoles par criblage differentiel de banques correspondants aux arn presents en debut de morphogenese. Le premier adnc correspond a un messager caracteristique de la phase de croissance lente du disque. Il est present dans le disque uniquement en absence de la 20-hydroxyedysone (20e). La proteine conceptuelle correspond a la proteine de stockage bmsp1(sakurai et coll, 1988). Bien que son fonctionnement soit arrete par l'hormone de mue dans le disque et le tissu adipeux, le gene bmsp1 ne semble pas soumis strictement a la meme regulation dans les 2 tissus. Des hybridations in situ ont confirme la presence du transcrit dans le disque imaginal alaire chez les males comme chez les femelles. Le role de cette proteine dans le disque n'apparait pas clairement. Le second adnc analyse correspond a une proteine de la famille alpha tubulines. Les homologies les plus fortes sont avec les tubulines alpha1 et alpha3 de drosophile (98,5% avec alpha1 et 98% avec alpha3). La repartition tissulaire ubiquiste suggere que cette proteine pourrait jouer le role des 2 tubulines alpha1 et alpha3 de drosophile. Le transcrit est present en permanence dans les organes avec une augmentation de la quantite dans le disque alaire lors de la morphogenese. Il est suggere que cette augmentation est liee a un remaniement du cytosquelette non reproduit dans notre modele experimental. Ces resultats suggerent que la morphogenese de l'aile comporte des etapes ou des sous programmes qui ne sont pas tous sous directement controles par le contexte hormonal.

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Lunke, Martine Dominique. "Molecular characterization of BmGATA-beta, a gene involved in choriogenesis in the silkworm Bombyx mori." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0027/NQ49515.pdf.

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33

Blossman-Myer, Bonnie Burggren Warren W. "A contravention of established principles of interspecific allometric metabolic scaling in developing silkworms, Bombyx mori." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3704.

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34

Blossman-Myer, Bonnie. "A Contravention of Established Principles of Interspecific Allometric Metabolic Scaling in Developing Silkworms, Bombyx Mori." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3704/.

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Established interspecific metabolic allometric relationships do not adequately describe the complexity and variable physiological states of developing animals. Consequently, intraspecific allometric relationships of oxygen consumption and carbon dioxide production as a function of body mass; the respiratory quotient; the function of the silk cocoon; and body composition were investigated for each distinct developmental stage of the silkworm, Bombyx mori. Whole animal O2 consumption in Bombyx ranged from 0.00064 + 0.000047 ml O2 .hr-1 at larval instar I to 0.77 + 0.06 ml O2 .hr-1 in pre-pupal, falling to 0.21+ 0.01 ml O2 .hr-1 in the pupae. Those instars having a significant relationship between O2 consumption as a function of body mass, the slope of the line relating O2 consumption to body mass varied between 0.99 and 1.02, while across all instars the slope was 0.82. Developmental allometry should be presented for individual developmental stages because the individual allometric exponents of the stages can be significantly different from the overall allometric exponent throughout development and in some cases, the overall allometric exponent can be a statistical artifact. The first larval instar of Bombyx mori has the lowest cross sectional area of high metabolic tissue of the midgut (27%) and had one of the highest percentages of some metabolically inert tissues (i.e. lipid, 7.5%). Body composition of the first instar does not support the idea that smaller mass animals having the highest O2 consumption are composed of a greater percentage of metabolically active organs when compared to larger animals. However, this developmental stage has the highest percentage of the mitochondrial marker cytochrome oxidase, which correlates well with the high O2 consumption rate of the smaller mass. Therefore, established interspecific principles should not be assumed to function as valid models for intraspecific developmental relationships of metabolism as a function of body mass. Developmental allometry should include an analysis of individual stages of development as well as an analysis of development as a whole to gain a comprehensive understanding of the complexity of allometry of the developing animal such as the silkworm.

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35

Chareyre, Pascal. "Isolement de clones ADNc exprimés pendant la différenciation de l'aile nymphale chez Bombyx mori : caractérisation d'un clone ADNc de collagène." Lyon 1, 1995. http://www.theses.fr/1995LYO10050.

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Le declenchement par une hormone steroide, la 20-hydroxyecdysone, de la formation d'une aile a partir d'un massif de cellules indifferenciees, le disque imaginal, est etudie chez le lepidoptere bombyx mori comme un modele de differenciation d'un organe. Notre objectif est de determiner comment est hierarchisee et coordonnee la cascade d'activation genique a l'origine de cette differenciation. La realisation puis le criblage differentiel d'une banque adnc de disques alaires de bombyx mori en cours de differenciation ont permis d'isoler un certain nombre de clones correspondant a des genes exprimes dans un contexte hormonal eleve et pendant le processus de morphogenese de l'aile. L'analyse des patrons d'expression au cours du developpement des arnm correspondant a quelques uns de ces clones permet de suggerer que la morphogenese de l'aile nymphale d'un lepidoptere commence deja lors de la derniere mue larvaire. Le clone bmcoll correspond a un arnm codant pour une proteine de la superfamille des collagenes. Il represente la premiere molecule de ce type decrite chez bombyx mori. La frequence des interruptions de la serie des triplets gly-xaa-yaa codant pour la triple helice collagenique lui confere un caractere de collagene non fibrillaire, mais les comparaisons avec les banques de donnees ne permettent pas d'identification formelle. Les acides amines representes aux positions xaa et yaa des triplets gly-xaa-yaa sont dans la majorite des cas la glutamine et la proline respectivement et la region ncl, completement originale, ne presente aucune homologie avec les regions c-terminales deja decrites. L'accumulation des messagers de bmcoll varie dans le meme sens que le taux de 20-hydroxyecdysone chez la larve. In vitro, le blocage de la synthese proteique par la cycloheximide provoque, comme avec la 20-hydroxyecdysone, l'accumulation des transcrits de bmcoll sous un delai d'une heure. Le modele de regulation qui est propose dans cette these suggere que les messagers de bmcoll, intrinsequement instables dans le disque pendant les phases de croissance lente de l'ebauche, sont stabilises en presence d'hormone par la disparition d'une proteine destabilisatrice hormone sensible. Cette hypothese est en accord avec la presence dans la region 3' non traduite de sequences responsables de l'instabilite de certains messagers de mammiferes. A notre connaissance, un tel mode de regulation n'a jamais ete decrit dans les modeles rendant compte de l'action de la 20-hydroxyecdysone sur le controle de l'activite genique

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Rao, Sudhakara P. "Studies on the evolution of adaptive bivoltine breeds of silkworm bombyx mori L. for tropical climates." Thesis, Studies on the evolution of adaptive bivoltine breeds of silkworm bombyx mori L. for tropical climates, 2003. http://hdl.handle.net/2009/3159.

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Diao, Yupu, Anrui Lu, Bing Yang, et al. "Existence of Prophenoloxidase in Wing Discs : A Source of Plasma Prophenoloxidase in the Silkworm, Bombyx mori." Uppsala universitet, Jämförande fysiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-184482.

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In insects, hemocytes are considered as the only source of plasma prophenoloxidase (PPO). PPO also exists in the hemocytes of the hematopoietic organ that is connected to the wing disc of Bombyx mori. It is unknown whether there are other cells or tissues that can produce PPO and release it into the hemolymph besides circulating hemocytes. In this study, we use the silkworm as a model to explore this possibility. Through tissue staining and biochemical assays, we found that wing discs contain PPO that can be released into the culture medium in vitro. An in situ assay showed that some cells in the cavity of wing discs have PPO1 and PPO2 mRNA. We conclude that the hematopoietic organ may wrongly release hemocytes into wing discs since they are connected through many tubes as repost in previous paper. In wing discs, the infiltrating hemocytes produce and release PPO probably through cell lysis and the PPO is later transported into hemolymph. Therefore, this might be another source of plasma PPO in the silkworm: some infiltrated hemocytes sourced from the hematopoietic organ release PPO via wing discs.

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Silva, Sóstenez Alexandre Vessaro da. "Descrição morfológica do intestino posterior e comportamento diferencial do reto de Bombyx mori frente ao AlfaBV." Universidade Estadual do Oeste do Parana, 2013. http://tede.unioeste.br:8080/tede/handle/tede/633.

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Made available in DSpace on 2017-07-10T14:17:03Z (GMT). No. of bitstreams: 1 sostenez.pdf: 5444547 bytes, checksum: 0e57c73e9d81ba62bd8cce82698d43f6 (MD5) Previous issue date: 2013-10-17 Bombyx mori nucleopolyhedrovirus (BmNPV) is an entomopathogenic and poliorganotrophic virus that infects Bombyx mori. BmNPV consists of a double strand DNA with two distinct phenotypes: the derived polyhedral virus (PDV), responsible for the primary infection in the insect s midgut; and the budded virus (BV), which disperses the infection in the hemocele, causing secondary or systemic infection. It is extremely virulent and when it infects silkworms, causes serious damages to the insect, usually leading to its death or harming the silk production, affecting all the productive chain, leading to economic losses. For a good silk production, a determinant factor is the functioning of the food duct, which is divided in foregut, midgut and hindgut, being the hindgut the place for water and mineral salts absorption and for the end of the digestive process. Several tissues have been established as virus targets, however, others have shown to be resilient to BmNPV. Given the importance of the hindgut, the present paper aimed to verify the susceptibility of its components, ileum, colon and rectum to an geographic isolated of BmNPV in Paraná, Brasil, the BmMNPV. In different post-inoculation days (dpi), the hindgut segment of 5th instar silkworms was dissected and processed for analysis in light microscopy, using conventional dyes and cytochemistry for viral detection and electronic scanning microscopy for the morphological details. The results revealed that the ileum, colon and rectum of the B. mori are constituted by simple epithelium, with alterations in cell morphology, covered by an intima in its luminal side, and that its organization is similar to that of other described insects. The cytological analysis of the ileum, colon and fore rectum revealed that its epithelial cells are not susceptible to BmMNPV in neither of the times analyzed. However, the posterior hindgut or anal duct showed itself to be susceptible to the virus after the 5º dpi, developing all the classic signs described for the infection with AlphaBV, as the presence of viroplasm, nuclear hypertrophy, polyhedra in formation and mature ones. At the end of the infectious cycle, occurs cell lysis with the liberation of viral polyhedra in the intestinal lumen and, consequently, to the external medium, coinciding with the death of the insect. Even with no infection in the other regions of the hindgut, the surrounding tissues have shown infected, affecting the normal functioning of this intestinal region, verified through changes in fecal pellet, which was less compact and changed format. These results will contribute in the establishment of the BmMNPV infectious cycle. Furthermore, the basic knowledge of viral behavior is important for the development of infection control, prevention and previous identification methods of this disease in the field, once it also makes possible the removal of infected silkworms, diminishing the horizontal transmission of the virus in the creation rooms, in a way to reduce the loss of cocoons to be used in the confection of silk yarn Bombyx mori nucleopolyhedrovirus multiple (BmMNPV) é um vírus entomopatogênico e poliorganotrófico, constituído por DNA fita dupla e apresenta dois fenótipos distintos: o vírus poliédrico derivado, responsável pela infecção primária no intestino médio do inseto; e o vírus broto, que se dispersa na hemocele causando a infecção secundária ou sistêmica. É extremamente virulento e quando infecta lagartas do bicho-da-seda, causa sérios danos ao inseto, geralmente levando-o à morte ou prejudicando a produção da seda, comprometendo toda a sua cadeia produtiva e gerando prejuízos econômicos. Para uma boa produção de seda, um fator determinante é o funcionamento do canal alimentar, que nos insetos é dividido em anterior, médio e posterior, sendo o posterior, local de absorção de água e sais minerais e da finalização do processo digestório. Vários tecidos já foram estabelecidos como alvos do BmMNPV, entretanto outros se mostraram resistentes. Dada a importância do intestino posterior, o presente trabalho objetivou verificar a susceptibilidade de seus componentes, íleo, cólon e reto de lagartas de B. mori do 5° instar ao BmMNPV isolado geográfico do Paraná. Em diferentes dias pós-inoculação (dpi), o intestino posterior foi dissecado e processado para análise em microscopia de luz, utilizando colorações convencionais e citoquímica para detecção viral, e microscopia eletrônica de varredura, para os detalhes morfológicos. Os resultados revelaram que o íleo, cólon e reto de B. mori apresentou morfologia semelhante a de outros lepidópteros. A análise citopatológica do íleo, cólon e o reto anterior revelou que suas células epiteliais não são susceptíveis ao BmMNPV, em nenhum dos tempos analisados. Já o reto posterior ou canal anal, mostrou-se susceptível ao vírus a partir do 5º dpi, desenvolvendo todos os sinais clássicos descritos para a infecção com o AlphaBV, como presença de viroplasma, hipertrofia nuclear, poliedros em formação e maduros. No final do ciclo infeccioso, ocorre a lise celular com a liberação dos poliedros virais para luz intestinal e, consequentemente, para o meio externo, coincidindo com a morte do inseto. Mesmo não havendo infecção nas demais regiões do intestino posterior, os tecidos circunvizinhos se mostraram infectados, o que possivelmente afetou o funcionamento normal desta região, sendo visíveis as modificações na formação do pellet fecal, que se mostrou menos compacto e com alterações no formato. Os resultados obtidos irão contribuir no estabelecimento do ciclo infeccioso deste patógeno. Além disso, o conhecimento básico do comportamento viral é importante para o desenvolvimento de métodos de controle da infecção, prevenção e identificação prévia desta doença no campo, pois, possibilita ainda, a retirada de lagartas infectadas, diminuindo a transmissão horizontal do vírus nos barracões de criação, de forma a reduzir a perda de casulos, a serem utilizados na confecção dos fios de seda

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Calado, Vanessa Rodrigues Ferreira. "BIOLOGIA REPRODUTIVA E CRIAÇÃO DE Trichospilus diatraeae (HYMENOPTERA: EULOPHIDAE) EM PUPAS DE Bombyx mori (LEPIDOPTERA: BOMBYCIDAE)." Universidade Federal da Grande Dourados, 2011. http://tede.ufgd.edu.br:8080/tede/handle/tede/442.

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Submitted by Cibele Nogueira (cibelenogueira@ufgd.edu.br) on 2017-03-28T17:50:48Z No. of bitstreams: 2 VANESSACALADO.pdf: 588287 bytes, checksum: 103bd85396851ece5815763aae21b26d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2017-03-28T17:50:48Z (GMT). No. of bitstreams: 2 VANESSACALADO.pdf: 588287 bytes, checksum: 103bd85396851ece5815763aae21b26d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2011-02-16 Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq The endoparasitoid Trichospilus diatraeae Margabandhu & Cherian, 1942 (Hymenoptera: Eulophidae) is parasites mainly pupae of Lepidoptera. Its potential as a biological control agent is not connected in Brazil. For this reason, this research aimed to evaluate the viability of the pupae of Bombyx mori Linnaeus, 1758 (Lepidoptera: Bombycidae) as an alternative host for T. diatraeae to optimize its creation in the laboratory. This research was conducted at the Laboratory of Entomology / Biological Control, Faculty of Agrarian Sciences, Federal University of Grande Dourados. Initially, we evaluated the development of T. diatraeae in hosts B.mori and Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae). Twelve pupae of B. mori and D. saccharalis, 72 and 24 hours old respectively and were exposed to parasitism by 21 female parasitoids. The duration of the life cycle of T. diatraeae was 19.44 ± 0.12 and 18.00 ± 0.05 days in pupae of D. saccharalis and B. mori, respectively, with 100% parasitism in both host and 66.6 and 75% emergence of the progeny of the parasitoid pupae of D. saccharalis and B. mori respectively. The progeny of T. diatraeae was 354.50 ± 43.21 and 469.11 ± 15.19 per pupa of D. saccharalis and B. mori, respectively. T. diatraeae shows good development in pupae of D. saccharalis and B. mori in the laboratory. Subsequently we estimated the density of female T. diatraeae created in pupae of B. mori. For this, the pupae of B. mori with 72 hours of age were exposed to parasitism by females of T. diatraeae 24 to 48 hours old, for 24 hours in parasitoid-host relationships 1:1, 14:1, 28:1, 56:1, 112:1 and 224:1, respectively, with 12 repetitions for each treatment. The percentage of parasitism of T. diatraeae in pupae of B. mori was 84% and 95% for the densities 1:1 and 56:1, respectively, and 100% for the others. The percentage of emergence of progeny ranged from 12% to 84% in the studied densities. The cycle of T. diatraeae was 24.20 ± 2.49 days and 20.00 ± 0.00 days at densities of 1:1 and 224:1, respectively. The density of 28 females of T. diatraeae by pupa of B. mori was the most suitable for rearing this parasitoid in the laboratory. Then we evaluated the effect of age of the pupae of B. mori on biological characteristics of T. diatraeae laboratory. Pupae of B. mori 24, 48, 72, 96 or 120 hours of age were exposed to parasitism by 28 females of T. diatraeae aged 24 to 48 hours of age for 24 hours and 12 replicates for each treatment. The percentage of parasitism of T. diatraeae in pupae of B. mori was 8.3% and 25% for pupae aged 24 and 48 hours respectively and 100% for the others. The percentage of emergence of progeny ranged from 0% to 91.6%. The cycle of T. diatraeae was 19.00 ± 0.00 days and 18.00 ± 0.35 days in the pupa ages of 48 and 120 hours respectively. Progeny pupa ranged from 277.00 ± 110.31 to 489.37 ± 255.40 descendants in the pupa ages of 48 and 120 hours respectively. Pupae of B. mori aged between 72 and 120 hours are better suited for creating T. diatraeae under laboratory conditions. We evaluated different temperatures on the development and parasitism of T. diatraeae in pupae of B. mori. Pupae of B. mori 72 hours old, were placed in separate glass vials with 28 females of T. diatraeae (24 to 48 hours old). The tubes containing the pupae with parasitoid females were transferred to a climatic chamber at temperatures of 16, 19, 22, 25, 28 or 31oC, 70 ± 10% relative humidity and photoperiod of 14 hours, respectively, where they were exposed to parasitism by 24 hours, with 12 repetitions for each treatment. The percentage of parasitism of T. diatraeae in pupae of B. mori was 91.6% for the temperatures of 16 and 19 ° C and 100% for the others. The percentage of emergence of progeny ranged from 0% to 58% for temperatures. The cycle of T. diatraeae was 60.00 ± 0.00 days and 15.71 ± 0.49 days at temperatures of 16 and 28 ° C, respectively. Progeny per pupa ranged from 23.00 ± 0.00 to 155.29 ± 86.80 offspring at temperatures of 16 and 28 ° C, respectively. T. diatraeae showed satisfactory development in pupae of B. mori at temperatures from 22 to 28 º C in the laboratory. These results contribute to the development of mass rearing techniques of T. diatraeae in pupae of B. mori and enables the use of natural enemies in biological control programs, especially the borer cane sugar D. saccharalis. O endoparasitóide Trichospilus diatraeae Cherian & Margabandhu, 1942 (Hymenoptera: Eulophidae) possui hábito gregário e parasita principalmente pupas de Lepidoptera. Seu potencial como agente de controle biológico é pouco conecido no Brasil. Por este motivo, esta pesquisa teve como objetivo avaliar a viabilidade de pupas de Bombyx mori Linneaus, 1758 (Lepidoptera: Bombycidae) como hospedeiro alternativo de T. diatraeae, visando otimizar sua criação em laboratório. Esta pesquisa foi conduzida no Laboratório de Entomologia/Controle Biológico da Faculdade de Ciências Agrárias da Universidade Federal da Grande Dourados. Inicialmente, avaliou-se a criação de T. diatraeae nos hospedeiros B.mori e Diatraea saccharalis (Fabricius,1794) (Lepidoptera: Crambidae). Doze pupas de B. mori e de D. saccharalis, de 72 e 24 horas de idade respectivamente e foram expostas ao parasitismo por 21 fêmeas parasitóides. A duração do ciclo de vida de T. diatraeae foi de 19,44 ± 0,12 e 18,00 ± 0,05 dias em pupas de D. saccharalis e B. mori, respectivamente, com 100% de parasitismo nos dois hospedeiros e 66,6 e 75% de emergência da progênie deste parasitóide em pupas de D. saccharalis e B. mori respectivamente. A progênie de T. diatraeae foi de 354,50 ± 43,21 e 469,11 ± 15,19 por pupa de D. saccharalis e B. mori, respectivamente. T. diatraeae apresenta bom desenvolvimento em pupas de D. saccharalis e de B. mori em laboratório. Posteriormente avaliou-se a densidade de fêmeas de T. diatraeae criado em pupas de B. mori. Para isso, pupas de B. mori com 72 horas de idade foram expostas ao parasitismo por fêmeas de T. diatraeae com 24 a 48 horas de idade, por 24 horas nas relações parasitóide-hospedeiro 1:1, 14:1, 28:1, 56:1, 112:1 ou 224:1, respectivamente, com 12 repetições para cada tratamento. A porcentagem de parasitismo de T. diatraeae em pupas de B. mori foi de 84% e 95% para as densidades 1:1 e 56:1, respectivamente e de 100% para as demais. A porcentagem de emergência de progênie variou de 12% a 84% nas densidades estudadas. A duração do ciclo de T. diatraeae foi de 24,20 ± 2,49 dias e de 20,00 ± 0,00 dias nas densidades de 1:1 e 224:1, respectivamente. A progênie por pupa variou de 37,60 ± 41,00 a 461,00 ± 0,00 descendentes por pupa, nas densidades de 1:1 e 224:1, respectivamente. A densidade de 28 fêmeas de T. diatraeae por pupa de B. mori foi a mais adequada para criação desse parasitóide em laboratório. Em seguida avaliou-se o efeito da idade de pupas de B. mori nas características biológicas de T. diatraeae em laboratório. Pupas de B. mori com 24, 48, 72, 96 ou 120 horas de idade, foram expostas ao parasitismo por 28 fêmeas de T. diatraeae com idade de 24 a 48 horas de idade por 24 horas e com 12 repetições, para cada tratamento. A porcentagem de parasitismo de T. diatraeae em pupas de B. mori foi de 8,3% e 25% para pupas com idades de 24 e 48 horas, respectivamente e de 100% para as demais. A porcentagem de emergência de progênie variou de 0% a 91,6%. A duração do ciclo de T. diatraeae foi de 19,00 ± 0,00 dias e de 18,00 ± 0,35 dias nas pupas com idades de 48 e 120 horas, respectivamente. A progênie por pupa variou de 277,00 ± 110,31 a 489,37± 255,40 descendentes nas pupas com idades de 48 e 120 horas, respectivamente. Pupas de B. mori com idades entre 72 a 120 horas são mais adequadas para criação de T. diatraeae em condições de laboratório. Avaliou-se diferentes temperaturas no parasitismo e desenvolvimento de T. diatraeae em pupas de B. mori. Pupas de B. mori com 72 horas de idade, foram individualizadas em tubos de vidro com 28 fêmeas de T. diatraeae (24 a 48 horas de idade). Os tubos contendo as pupas com as fêmeas parasitóides foram transferidos para câmaras climatizadas nas temperaturas de 16, 19, 22, 25, 28 ou 31oC, 70 ± 10% de umidade relativa e fotofase de 14 horas, respectivamente, onde foram expostas ao parasitismo por 24 horas, com 12 repetições para cada tratamento. A porcentagem de parasitismo de T. diatraeae em pupas de B. mori foi de 91,6% para as temperaturas de 16 e 19ºC e de 100% para as demais. A porcentagem de emergência de progênie variou de 0% a 58% para temperaturas testadas. A duração do ciclo de T. diatraeae foi de 60,00 ± 0,00 dias e de 15,71 ± 0,49 dias nas temperaturas de 16 e 28ºC, respectivamente. A progênie por pupa variou de 23,00 ± 0,00 a 155,29 ± 86,80 descendentes nas temperaturas de 16 e 28ºC, respectivamente. T. diatraeae apresentou desenvolvimento satisfatório em pupas de B. mori nas temperaturas de 22 a 28 ºC em laboratório. Esses resultados contribuem para o desenvolvimento de técnicas de criação em massa de T. diatraeae em pupas de B. mori e viabiliza o uso desse inimigo natural em programas de controle biológico, especialmente da broca-da-cana-de-açúcar D. saccharalis.

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Dencausse, Laurent. "Valorisation de matières premières végétales et animales pour l'industrie des cosmétiques : Pentadesma butyracea, Equus caballus, Bombyx mori." Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30043.

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Ce travail est consacre a l'etude de matieres premieres et d'actifs liposolubles destines a l'industrie des cosmetiques. Les beurres de pentadesma et de karite sont des matieres grasses vegetales qui ont des proprietes physico-chimiques et cosmetiques tres voisines. A ce jour, seul le beurre de karite est utilise dans l'industrie cosmetique. Une etude comparative des deux beurres montre que les compositions en acides gras et en triglycerides sont tres proches. De la meme maniere, les fractions insaponifiables sont constituees essentiellement d'alcools triterpeniques. Les principaux sont l' et la -amyrine, le butyrospermol et le lupeol. Les deux beurres different par leur composition sterolique constituee de <7-sterols (-spinasterol et <7-stigmastenol) pour le karite et d'un melange de <5 et <7-sterols pour le pentadesma ou le stigmasterol domine ce qui est rarement rencontre dans la nature. L'analyse de cette fraction permet de determiner l'origine botanique des beurres et l'existence de melanges eventuels notamment dans les preparations cosmetiques. Les n-acylaminoacides sont des actifs qui presentent des proprietes physico-chimiques et biologiques interessantes pour le maintien et le retablissement physiologique de l'epiderme. La synthese des n-acylaminoacides est realisee par reaction d'acides amines et d'un agent acylant. Une voie de synthese elaboree en milieu organique anhydre a ete appliquee avec succes a des hydrolysats de fibroine de soie et de crin de cheval. Les n-palmitoylaminoacides correspondants ont ete caracterises et doses par chromatographie en phase liquide. Une formulation (huile/eau) a ete realisee a partir des beurres de pentadesma et de karite ainsi qu'avec des n-palmitoylaminoacides. Cette composition presente des qualites rheologiques et cosmetiques particulierement interessantes pour le developpement d'une nouvelle ligne de produits cosmetiques.

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Horard, Béatrice. "Régulation tissulaire et cellulaire du gène de la protéine P25 de Bombyx mori : études fonctionnelles in vivo." Lyon 1, 1995. http://www.theses.fr/1995LYO10047.

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Le gene p25 de bombyx mori, codant une proteine de la soie, se caracterise par une regulation stricte de sa transcription dans le temps et l'espace. En effet, il est abondamment et exclusivement transcrit dans les cellules posterieures de la glande sericigene, et ceci, uniquement durant les periodes d'intermues larvaires. Dans le but d'apprehender les mecanismes moleculaires a l'origine de l'expression selective de p25, nous avons recherche les elements cis-regulateurs essentiels pour promouvoir in vivo cette activite specifique. Nous avons alors developpe un protocole de transfection des cellules sericigenes differenciees par biolistique. Ce protocole consiste a projeter, sur une glande sericigene prelevee extemporanement, des microprojectiles enrobes d'adn et acceleres a tres grande vitesse, l'organe ainsi traite etant ensuite reintroduit pour 48 heures dans une larve hote. De facon remarquable, la territorialite d'expression de p25 dans la glande sericigene est alors reproduite avec une tres grande efficacite. Par ce systeme d'expression transitoire, nous avons demontre que tous les elements essentiels a l'expression de p25 dans les cellules posterieures de la glande sericigene sont presents dans les 165 premieres paires de bases du promoteur. Dans cette region proximale, un element s'est avere indispensable a l'activation trancriptionnelle de p25. Il s'agit de l'element sgfb, defini auparavant par sa capacite a lier in vitro un facteur specifique des cellules sericigenes. Toutefois, notre analyse tend a demontrer qu'un element localise entre les positions -165 et -119 est requis en association avec l'element sgfb pour promouvoir le fonctionnement de p25 in vivo. De facon remarquable, les conclusions de cette analyse fonctionnelle peuvent etre correlees aux resultats de l'analyse de la structure chromatinienne entourant le gene p25. Parallelement a cette approche, l'etude du fonctionnement de p25 a ete abordee en utilisant la transgenese chez drosophila melanogaster. Cette etude a confirme que toutes les informations necessaires a la regionalisation de l'expression de p25 sont compris dans un court domaine de sequences proximales. De fait, nos resultats demontrent que malgre une divergence evolutive d'environ 250 millions d'annees, les mecanismes de regulation de l'expression des genes sont etonnamment conserves entre b. Mori et d. Melanogaster

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Ikeda, Kento. "Role of the clock gene period in the circadian rhythm and photoperiodism of the silkmoth Bombyx mori." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/264645.

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Martinez, Maria Juanita. "Transcription factor IIIB binding to two classes of Alanine tRNA gene promoters of the silkmoth, Bombyx mori /." view abstract or download file of text, 2001. http://wwwlib.umi.com/cr/uoregon/fullcit?p3018382.

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Thesis (Ph. D.)--University of Oregon, 2001. Typescript. Includes vita and abstract. Includes bibliographical references (leaves 128-143). Also available for download via the World Wide Web; free to University of Oregon users.

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Romoli, Ottavia. "Antimicrobial peptide-mediated immune response in four Bombyx mori strains infected with Gram-positive and -negative pathogens." Doctoral thesis, Università degli studi di Padova, 2016. http://hdl.handle.net/11577/3424450.

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The domesticated silkworm Bombyx mori is an important organism for its intrinsic economic and biotechnological value, but also for representing a model organism for Lepidoptera genetics. Silkworm strains can be grouped into four geographical types (Japanese, Chinese, European and Tropical) characterized by a different resistance to infections, which is inversely correlated to the silk productivity. The aim of this project was to characterize which are the main elements of the immune response protecting Bombyx mori against pathogen infections, with the final purpose to obtain silkworms enhanced in their pathogen-resistance, but still maintaining good production capabilities. To achieve this objective, two main approaches have been used: 1) the characterization of the humoral immune response to oral infection of four B. mori strains originating from Japan, China, Europe and India, focusing on antimicrobial peptides (AMPs), important effectors of the innate immunity; 2) the production and characterization of transgenic silkworms over-expressing specific AMPs. We first characterized the four strain under germ-free conditions for the structure of their peritrophic membranes and intestinal epithelia, which represent the first barriers for oral infection. Moreover, we evaluated the genetic variability of the four strains at the level of the 21 B. mori AMP genes, identifying several amino acid substitutions in the active portion of peptides. To determine the possible differential sensitivity to microbial attack, we performed infection experiments in which each B. mori line was exposed to two silkworm pathogens, the Gram-positive Enterococcus mundtii or the Gram-negative Serratia marcescens. After a 24h oral infection, the differential response to pathogens of the four strains was determined by comparing 1) the survival profiles, 2) the presence of living pathogen cells in the hemolymph circulation, 3) the expression induction of 9 representative AMP genes in the tissues involved in the immune response (fat bodies and midgut), 4) the in vitro antimicrobial activity of the silkworm hemolymph, 5) the Lysozyme concentration in larvae plasma and 6) the rate of the melanization reaction. Regarding the E. mundtii infection, the European line was found to be the most resistant, followed by the Chinese, the Indian and the Japanese strains. Our data suggest that the key resistance factor might consist in the AMP classes and/or isoforms produced in the European strain at both local and systemic levels. Regarding the S. marcescens infection, the Indian strain was completely resistant, while none of the other three strains survived to the microbial exposure. We found a general correlation between the survival profile and the systemic AMP transcription activation. In fact, the Indian line was the only one which showed a systemic induction of most AMPs and in which no viable bacteria were found in the hemolymph. Further analyses are required to explore whether this strain-specific resistance is due to more efficient mechanisms in the Gram-negative recognition process or in the signal transduction pathway activation. In order to obtain transgenic silkworm strains with enhanced pathogen resistance, we generated three different piggyBac-based constructs to achieve the over-expression of moricin, gloverin2 or cecropinB at the level of fat bodies. Currently, 2 independent lines over-expressing moricin have been obtained and are under evaluation for their resistance to infections. Il baco da seta, Bombyx mori, oltre a possedere un’importanza economica intrinseca, è ampiamente utilizzato sia come sistema modello per i Lepidotteri, che nel campo delle biotecnologie. In seguito alla domesticazione si sono originati numerosi ceppi, che possono essere classificati sulla base della loro origine geografica in giapponesi, cinesi, europei e tropicali. In genere, i ceppi che provengono dalle aree temperate mostrano una maggiore produttività, ma anche una più alta suscettibilità alle infezioni, mentre i ceppi di origine tropicale risultano essere più resistenti alle infezioni. Lo scopo di questo progetto consisteva nell’identificare quali potessero essere gli elementi chiave della resistenza del B. mori alle infezioni. Il fine ultimo era di creare dei ceppi di baco da seta che fossero più tolleranti ai patogeni, ma che mantenessero comunque buone capacità produttive. Per raggiungere questi obiettivi, sono stati utilizzate due principali strategie: 1) la caratterizzazione della risposta immunitaria indotta da infezioni orali di quattro ceppi di baco da seta originatisi rispettivamente in Giappone, Cina, Europa ed India, ponendo particolare attenzione sui peptidi antimicrobici (AMP), i principali effettori dell’immunità innata; 2) la produzione e la caratterizzazione di linee transgeniche over-esprimenti i geni codificanti gli AMP. In primo luogo abbiamo caratterizzato la morfologia delle membrane peritrofiche e degli epiteli intestinali dei quattro ceppi allevati in condizioni sterili. Queste strutture rappresentano la prima barriera fisica durante le infezioni orali. Successivamente, abbiamo valutato la variabilità genetica dei quattro ceppi a livello dei 21 geni codificanti per gli AMP di B. mori, identificando numerose sostituzioni amminoacidiche nella porzione attiva dei peptidi. Abbiamo quindi sottoposto i quattro ceppi ad infezione orale con due batteri, specifici patogeni del baco da seta: Enterococcus mundtii, Gram-positivo, e Serratia marcescens, Gram-negativo. In seguito ad un’infezione di 24 ore abbiamo valutato la risposta differenziale dei quattro ceppi confrontando: 1) i profili di sopravvivenza, 2) la presenza di cellule batteriche vive nell’emolinfa, 3) l’induzione dell’espressione dei geni codificanti 9 AMP rappresentativi, 4) l’attività antimicrobica dell’emolinfa, 5) la concentrazione del Lisozima nel plasma, 6) la velocità di melanizzazione dell’emolinfa. Per quanto riguarda l’infezione con E. mundtii, il ceppo europeo è risultato essere il più resistente, seguito dal cinese, dall’indiano e dal giapponese. I dati ottenuti indicano che le classi e i tipi di AMP prodotti dal ceppo europeo, sia a livello locale che a quello sistemico, possano essere l’effettiva causa della maggiore resistenza di questo ceppo. A seguito dell’infezione con S. marcescens, il ceppo Indiano si è rivelato essere totalmente resistente a questo patogeno, mentre nessuno degli altri tre ceppi è sopravvissuto all’infezione. Abbiamo trovato una generale correlazione tra il profilo di sopravvivenza e l’attivazione sistemica degli AMP. Infatti nell’emolinfa dei bachi da seta indiani non sono state isolate cellule batteriche di S. marcescens e solamente questo ceppo ha mostrato un’induzione della trascrizione della maggior parte degli AMP. Sono necessarie ulteriori analisi per verificare se il ceppo indiano possieda meccanismi di riconoscimento o vie di trasduzione del segnale più efficaci per questo tipo di infezione. Infine sono stati generati tre differenti costrutti basati sull’elemento trasponibile piggyBac per ottenere ceppi di baco da seta transgenici con una maggiore resistenza alle infezioni. Sono state ottenute due linee indipendenti over-esprimenti il gene per la Moricina. Al momento si stanno caratterizzando queste linee per verificare la loro resistenza alle infezioni.

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Brigaud, Isabelle. "Réception phéromonale et sa modulation chez les Noctuelles : focus sur les mécanismes moléculaires impliqués." Paris 6, 2008. http://www.theses.fr/2008PA066555.

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Glushek, Martin. "The transcriptional regulator BmGATAß of the silkmoth Bombyx mori, isolation of putative interacting factors from ovarian follicular cells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ64953.pdf.

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Baig, Murthuza. "Studies on nosema bombycis N- A pathogen of silk worm bombyx mori L." Thesis, 1994. http://hdl.handle.net/2009/2772.

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Kumar, Pradip. "Contribution to our knowledge on tricholyga bombycis BECK -A serious parasite of bombyx mori L. and its control." Thesis, 1987. http://hdl.handle.net/2009/2470.

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Valluzzi, Regina. "The interfacial behavior of Bombyx mori silk fibroin." 1998. https://scholarworks.umass.edu/dissertations/AAI9909229.

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A new crystal structure has been observed for Bombyx mori silk fibroin at air-water interfaces. This structure, silk III, incorporates a left-handed three-fold polyglycine II conformation and an approximately hexagonal lattice. Detailed crystallographic studies using electron diffraction data have been used to characterize the silk III crystal structure. There is a hexapeptide repetitive sequence found in the crystallizable portions of silk fibroin. When this sequence, Gly-Ala-Gly-Ala-Gly-Ser, is in a threefold helical conformation, a row of alternating glycine and serine residues parallel to the helical axis results. One third of the helix thus becomes slightly hydrophilic, whereas the other two thirds consist of glycine and hydrophobic alanine residues. The data indicate that the helices are arranged so that the serine residues pack preferentially in serine-rich sheets in the (110) planes of the crystal. The result is a monoclinic crystal structure, where the basal plane angle $\gamma$ is 116$\sp\circ$ rather than the 120$\sp\circ$ expected for perfect hexagonal packing, due to the distortion in nearest neighbor interhelical packing distances that results when the serine residues have a preferred packing. The separation of hydrophobic and hydrophilic residues in a threefold helical conformation of fibroin suggests that the air-water interface may stabilize the threefold conformation because this conformation allows the fibroin to behave as a surfactant at the interface. The sheet-like arrangement of serine residues deduced for the monoclinic silk III crystallites also supports a role for surfactancy in stabilizing the silk III structure at the air-water interface. If the crystallizable portions of fibroin are behaving as a surfactant, then the three-fold helical silk III structure should be oriented with the axes of the three-fold fibroin helices in the plane of the interface. This orientation is observed in uncompressed fibroin films which were picked up onto TEM grids. In LB films compressed to 16.7 mN/meter on the trough prior to being picked up onto TEM grids a uniaxial orientation is observed for silk III, with the helical axes perpendicular to the plane of the sample film. A surface compression of 34 mN/meter results in films containing silk II crystallites with the same uniaxial orientation, placing the helical axes perpendicular to the plane of the film. In addition to air-water interface experiments several experiments were carried out using aqueous-organic interfaces. A hydrated crystal structure incorporating a left-handed 6/2 helix which is still roughly three-fold, is observed at the water-hexane and water-chloroform interfaces. Large lamellar crystallites possessing a hexagonal habit were observed at both of these interfaces. A banded cholesteric mesophase which in some regions crystallizes into the same silk III hydrate structure as the lamellae was also observed and characterized.

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SAJWAN, Suresh Chandra Singh. "Gene targeting in Silkworm (Bombyx mori) by Engineered Endonucleases." Doctoral thesis, 2013. http://www.nusl.cz/ntk/nusl-151839.

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This thesis describes the establishment of a precise gene targeting methodology in the silkworm Bombyx mori by technologies based on engineered endonucleases. Two classes of engineered endonucleases, ZFNs and full length TALENs were used for creating DSBs at specified sites in the colour marker genes (BmBlos2 and Bmwh3). Direct embryo microinjection of engineered nucleases mRNA were performed and let the nuclease proteins to disrupt the functions of these marker genes by creating DSBs and inducing error prone NHEJ mechanism. These experiments showed that both ZFNs and TALENs could be used for targeted gene disruption in silkworms.

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Dissertations / Theses on the topic 'Bombyci mori'

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