Academic literature on the topic 'Branchiostoma'

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Journal articles on the topic "Branchiostoma"

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He, Chunpeng, Tingyu Han, Xin Liao, et al. "Phagocytic intracellular digestion in amphioxus ( Branchiostoma )." Proceedings of the Royal Society B: Biological Sciences 285, no. 1880 (2018): 20180438. http://dx.doi.org/10.1098/rspb.2018.0438.

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The digestive methods employed by amphioxus ( Branchiostoma )—both intracellular phagocytic digestion and extracellular digestion—have been discussed since 1937. Recent studies also show that epithelial cells lining the Branchiostoma digestive tract can express many immune genes. Here, in Branchiostoma belcheri , using a special tissue fixation method, we show that some epithelial cells, especially those lining the large diverticulum protruding from the gut tube, phagocytize food particles directly, and Branchiostoma can rely on this kind of phagocytic intracellular digestion to obtain energy throughout all stages of its life. Gene expression profiles suggest that diverticulum epithelial cells have functional features of both digestive cells and phagocytes. In starved Branchiostoma , these cells accumulate endogenous digestive and hydrolytic enzymes, whereas, when sated, they express many kinds of immune genes in response to stimulation by phagocytized food particles. We also found that the distal hindgut epithelium can phagocytize food particles, but not as many. These results illustrate phagocytic intercellular digestion in Branchiostoma , explain why Branchiostoma digestive tract epithelial cells express typical immune genes and suggest that the main physiological function of the Branchiostoma diverticulum is different from that of the vertebrate liver.
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Bi, Changwei, Na Lu, Tingyu Han, et al. "Whole-Genome Resequencing of Twenty Branchiostoma belcheri Individuals Provides a Brand-New Variant Dataset for Branchiostoma." BioMed Research International 2020 (January 26, 2020): 1–15. http://dx.doi.org/10.1155/2020/3697342.

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As the extant representatives of the basal chordate lineage, amphioxi (including the genera Branchiostoma, Asymmetron and Epigonichthys) play important roles in tracing the state of chordate ancestry. Previous studies have reported that members of the Branchiostoma species have similar morphological phenotypic characteristics, but in contrast, there are high levels of genetic polymorphisms in the populations. Here, we resequenced 20 Branchiostomabelcheri genomes to an average depth of approximately 12.5X using the Illumina HiSeq 2000 platform. In this study, over 52 million variations (~12% of the total genome) were detected in the B. belcheri population, and an average of 12.8 million variations (~3% of the total genome) were detected in each individual, confirming that Branchiostoma is one of the most genetically diverse species sequenced to date. Demographic inference analysis highlighted the role of historical global temperature in the long-term population dynamics of Branchiostoma, and revealed a population expansion at the Greenlandian stage of the current geological epoch. We detected 594 Single nucleotide polymorphism and 148 Indels in the Branchiostoma mitochondrial genome, and further analyzed their genetic mutations. A recent study found that the epithelial cells of the digestive tract in Branchiostoma can directly phagocytize food particles and convert them into absorbable nontoxic nutrients using powerful digestive and immune gene groups. In this study, we predicted all potential mutations in intracellular digestion-associated genes. The results showed that most “probably damaging” mutations were related to rare variants (MAF < 0.05) involved in strengthening or weakening the intracellular digestive capacity of Branchiostoma. Due to the extremely high number of polymorphisms in the Branchiostoma genome, our analysis with a depth of approximately 12.5X can only be considered a preliminary analysis. However, the novel variant dataset provided here is a valuable resource for further investigation of phagocytic intracellular digestion in Branchiostoma and determination of the phenotypic and genotypic features of Branchiostoma.
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Klootwijk, Wim, Edith C. H. Friesema, and Theo J. Visser. "A Nonselenoprotein from Amphioxus Deiodinates Triac But Not T3: Is Triac the Primordial Bioactive Thyroid Hormone?" Endocrinology 152, no. 8 (2011): 3259–67. http://dx.doi.org/10.1210/en.2010-1408.

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Thyroid hormone (TH) is important for metamorphosis in many species, including the cephalochordate Branchiostoma floridae, a marine invertebrate (amphioxus) living in warmer coastal areas. Branchiostoma expresses a TH receptor, which is activated by 3,3′,5-triiodothyroacetic acid (TA3) but not by T3. The Branchiostoma genome also contains multiple genes coding for proteins homologous to iodothyronine deiodinases in vertebrates, selenoproteins catalyzing the activation or inactivation of TH. Three Branchiostoma deiodinases have been cloned: two have a catalytic Sec, and one, bfDy, has a Cys residue. We have studied the catalytic properties of bfDy in transfected COS1 cells by HPLC analysis of reactions with 125I-labeled substrates and dithiothreitol as cofactor. We could not detect deiodination of T4, T3, or rT3 by bfDy but observed rapid and selective inner ring deiodination (inactivation) of TA3 and 3,3′,5,5′-tetraiodothyroacetic acid (TA4). Deiodination of TA3 by bfDy was optimal at 25 C and 10 mm dithiothreitol. bfDy was extremely labile at 37 C, showing a half-life of less than 2 min, in contrast with a half-life of more than 60 min at 25 C. Deiodination of labeled TA3 was inhibited dose dependently by unlabeled TA3≈TA4>T4≈T3. Michaelis-Menten analysis yielded Michaelis-Menten constant values of 6.8 and 68 nm and maximum velocity values of 1.4 and 5.4 pmol/min·mg protein for TA3 and TA4, respectively. bfDy was not inhibited by propylthiouracil and iodoacetate and only weakly by goldthioglucose and iopanoic acid. In conclusion, we demonstrate rapid inactivation of TA3 and TA4 but not of T3 and T4 by the first reported natural nonselenodeiodinase. Our findings support the hypothesis that TA3 is a primordial bioactive TH.
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Niang, Tania Marcia S., André Luiz M. Pessanha, and Francisco Gerson Araújo. "Dieta de juvenis de Trachinotus carolinus (Actinopterygii, Carangidae) em praias arenosas na costa do Rio de Janeiro." Iheringia. Série Zoologia 100, no. 1 (2010): 35–42. http://dx.doi.org/10.1590/s0073-47212010000100005.

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Estudamos a dieta dos juvenis de Trachinotus carolinus (Linnaeus, 1766) em praias da Baía de Sepetiba (Rio de Janeiro, Brasil) entre janeiro de 2000 e abril de 2001. Procuramos avaliar a plasticidade trófica de peixes desta espécie ao longo de um gradiente espacial com diferentes níveis de exposição às ondas, sazonalidade, além de avaliar mudanças ontogenéticas na dieta. Os itens alimentares foram analisados através do índice de importância relativa (IIR), determinado pelos valores das frequências de ocorrência, de número e de peso. Os itens de maior importância foram do subfilo Crustacea, ordens Mysidacea, e o representante da ordem Decapoda Emerita brasiliensis (Schmitt, 1935), além de Cefalochordata, representado por Branchiostoma platae (Fitzinger, 1862). Na zona de maior exposição às ondas (praia de Barra de Guaratiba) e com substrato predominantemente arenoso, a dieta foi constituída principalmente por Emerita brasiliensis e Cirripedia, este último presente nos costões rochosos que limitam a praia; na zona de exposição intermediária (praia de Muriqui), houve um predomínio de Mysidacea e Branchiostoma platae; na zona mais protegida (praia de Itacuruçá), os itens de maior abundância foram Polychaeta, Mysidacea e Branchiostoma platae. Sazonalmente não ocorreu variação no uso de Mysidacea, enquanto Branchiostoma platae foi mais consumido durante o inverno, Polychaeta na primavera e Cirripedia e Emerita brasiliensis, no verão. Mysidacea foi o alimento predominante em todas as classes de tamanho, enquanto Polychaeta foi utilizado predominantemente por peixes menores que 20 mm de comprimento padrão e Emerita brasiliensis e Cirripedia foram consumidos principalmente por indivíduos maiores que 40 mm, somente na praia de maior exposição. O sucesso no uso de praias desprotegidas e zonas de arrebentação por esta espécie de peixe pode ser em parte devido à estratégia trófica oportunista, que utiliza uma ampla variedade de recursos disponíveis no ambiente.
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Vergara, Makarena, Marcelo E. Oliva, and José M. Riascos. "Population dynamics of the amphioxus Branchiostoma elongatum from northern Chile." Journal of the Marine Biological Association of the United Kingdom 92, no. 3 (2011): 591–99. http://dx.doi.org/10.1017/s0025315411000804.

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Amphioxi represent the evolutionary link between vertebrates and invertebrates. For this reason, research dealing with these animals has been focused mainly on embryological and anatomical studies. Out of 30 described species, only one, Branchiostoma elongatum, is known to inhabit shallow sandy bottoms along the Humboldt Current System (HCS) of Chile and Peru. The population dynamics of B. elongatum from northern Chile was studied between February 2008 and January 2009, and the results were compared with other species within the genus Branchiostoma inhabiting distinct ecosystems. Mean abundance of B. elongatum was low (158.6 ind m−2) in comparison with the abundance of other species within Branchiostoma. Although the gametogenic activity was continuous, a clear spawning event was observed between August and October, which seemingly produced a recruitment pulse during the summer and consequently a simultaneous increase in population density and decrease of mean length during that period. Growth of B. elongatum was best fitted to the seasonalized von Bertalanffy growth function (K = 0.45 year−1 and L∞ = 64.6 mm), with faster growth during summer–autumn. Growth performance (Ф′ = 3.273) was high in comparison with other species within the genus. Mortality of B. elongatum (Z = 1.075 year−1) was well fitted to the single exponential model (r2 = 0.92). The annual total production of B. elongatum reached 0.68 g ash-free dry mass (AFDM) m−2 and the annual mean biomass was 0.56 g AFDM m−2, which determined a production to biomass ratio of 1.22. The huge productivity of the HCS was not reflected in a high abundance and biomass of B. elongatum. However, this species displayed a high growth efficiency and P/B ratio that are comparable to those of other Branchiostoma inhabiting highly productive ecosystems.
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Kusakabe, Rie, Noriyuki Satoh, Linda Z. Holland, and Takehiro Kusakabe. "Genomic organization and evolution of actin genes in the amphioxus Branchiostoma belcheri and Branchiostoma floridae." Gene 227, no. 1 (1999): 1–10. http://dx.doi.org/10.1016/s0378-1119(98)00608-8.

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Bi, Changwei, Na Lu, Zhen Huang, Junyuan Chen, Chunpeng He, and Zuhong Lu. "Whole‐genome resequencing reveals the pleistocene temporal dynamics of Branchiostoma belcheri and Branchiostoma floridae populations." Ecology and Evolution 10, no. 15 (2020): 8210–24. http://dx.doi.org/10.1002/ece3.6527.

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Nishikawa, Teruaki. "Reinstatement of the Lancelet Name Asymmetron lucayanum, Recently Proposed as a Junior Synonym of Branchiostoma pelagicum (Cephalochordata)." Species Diversity 23 (May 25, 2018): 83–85. https://doi.org/10.12782/specdiv.23.83.

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Nishikawa, Teruaki (2018): Reinstatement of the Lancelet Name Asymmetron lucayanum, Recently Proposed as a Junior Synonym of Branchiostoma pelagicum (Cephalochordata). Species Diversity 23: 83-85, DOI: 10.12782/specdiv.23.83
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Del Moral-Flores, Luis Fernando, Miguel Ángel Guadarrama-Martínez, and César Flores-Coto. "Taxonomic composition and distribution of cephalochordates (Cephalochordata: Amphioxiformes) from Mexico." Latin American Journal of Aquatic Research 44, no. 3 (2017): 497–503. http://dx.doi.org/10.3856/vol44-issue3-fulltext-8.

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Based on the number of specimens examined, review of reference collections and literature, we determined the presence of four cephalochordates (two genera and one family) in the seas of Mexico; moreover, the registry of the locations is denoted also a taxonomic key for their identification comes attached. The presence of three of the four species for the Gulf of Mexico and the Mexican Caribbean is registered, of which Branchiostoma caribaeum has the largest distributional area, from Veracruz coasts to the Yucatan Peninsula; B. longirostrum has been registered only on the west part of the Gulf of Mexico and Asymmetron lucayanum in front of the northeastern coast of Yucatan. Branchiostoma californiense is the only one registered on the Pacific coast of Mexico but it counts with a wider distribution.
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Yu, Jr-Kai, Francoise Mazet, Yen-Ta Chen, Song-Wei Huang, Kuo-Chen Jung, and Sebastian M. Shimeld. "The Fox genes of Branchiostoma floridae." Development Genes and Evolution 218, no. 11-12 (2008): 629–38. http://dx.doi.org/10.1007/s00427-008-0229-9.

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Dissertations / Theses on the topic "Branchiostoma"

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Luke, Graham Nigel. "The NK homeobox gene cluster of Branchiostoma floridae." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408097.

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Le, Petillon Yann. "Etude fonctionnelle de l'induction neurale chez le céphalochordé Branchiostoma lanceolatum." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066116/document.

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L’induction neurale est le processus au travers duquel les cellules ectodermiques de l’embryon deviennent neurales. De nombreuses études sur les mécanismes contrôlant ce processus on été réalisées mais du fait de sa complexité, de nombreuses questions restent sans réponse. Au cours de ce travail de thèse, je me suis intéressé à l’étude de l’induction neurale sous une perspective évolutive en étudiant ce processus chez le céphalocordé amphioxus, l’un des plus proches parents des vertébrés. J’ai pu mettre en évidence que, comme les vertébrés, l’amphioxus possède un organisateur. J’ai également confirmé une conservation du rôle des voies de signalisation BMP et FGF respectivement dans l’induction de l’épiderme et la régionalisation du tissu neural. Cependant, au contraire des vertébrés, le signal FGF ne semble pas être un acteur prépondérant de l’induction neurale. Au contraire, un rôle important de la voie de signalisation Activine/Nodal a été mis en évidence.Les résultats obtenus soutiennent d’une part la conservation de certains aspects de ce mécanisme chez tous les chordés, et suggèrent d’autre part l’implication de certains acteurs comme la voie Activine/Nodal jusque là inconnue chez les vertébrés. La position phylogénétique de l’amphioxus et la conservation globale de ce processus entre les céphalochordés et les vertébrés nous permettent de suggérer que l’ancêtre des chordés formait du tissue neurale au travers des mécanismes mis en évidence dans cet étude. Ces résultats nous permettent également de proposer de nouvelles études chez les vertébrés visant à établir un rôle putatif de la voie Activine/Nodal au cours de ce processus, rôle jusque la complètement inconnu<br>Neural induction is the process through which embryonic ectodermal cells become neural. Many studies on the mechanisms controlling this process have been made, but because of its complexity, many questions remain unanswered. In this thesis, I have focused my interest on the study of neural induction in an evolutionary context studying this process in the cephalochordate amphioxus, one of the closest relatives of vertebrates. I have highlighted that amphioxus, as vertebrates, possesses an organizer. I have demonstrated a conservation of the role of BMP and FGF signals in the induction of the epidermis and the regionalization of neural tissue respectively. However, in contrast to vertebrates, FGF signal does not appear to be a major player in neural induction. Instead, an important role of Activin/Nodal signaling pathway has been demonstrated. These results support, first, the conservation of several aspects of this mechanism in all chordates, and second, they suggest the involvement of the Activin/Nodal signaling in this process, something previously unknown in vertebrates. The phylogenetic position of amphioxus and the overall conservation of this process between cephalochordates and vertebrates allow us to suggest that the ancestor of chordates formed its neural tissue through mechanisms highlighted in this study. These results also allow us to propose new studies in vertebrates for establishing a putative role of the Activin/Nodal signaling during this process, a role previously completely unknown
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Le, Petillon Yann. "Etude fonctionnelle de l'induction neurale chez le céphalochordé Branchiostoma lanceolatum." Electronic Thesis or Diss., Paris 6, 2014. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2014PA066116.pdf.

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L’induction neurale est le processus au travers duquel les cellules ectodermiques de l’embryon deviennent neurales. De nombreuses études sur les mécanismes contrôlant ce processus on été réalisées mais du fait de sa complexité, de nombreuses questions restent sans réponse. Au cours de ce travail de thèse, je me suis intéressé à l’étude de l’induction neurale sous une perspective évolutive en étudiant ce processus chez le céphalocordé amphioxus, l’un des plus proches parents des vertébrés. J’ai pu mettre en évidence que, comme les vertébrés, l’amphioxus possède un organisateur. J’ai également confirmé une conservation du rôle des voies de signalisation BMP et FGF respectivement dans l’induction de l’épiderme et la régionalisation du tissu neural. Cependant, au contraire des vertébrés, le signal FGF ne semble pas être un acteur prépondérant de l’induction neurale. Au contraire, un rôle important de la voie de signalisation Activine/Nodal a été mis en évidence.Les résultats obtenus soutiennent d’une part la conservation de certains aspects de ce mécanisme chez tous les chordés, et suggèrent d’autre part l’implication de certains acteurs comme la voie Activine/Nodal jusque là inconnue chez les vertébrés. La position phylogénétique de l’amphioxus et la conservation globale de ce processus entre les céphalochordés et les vertébrés nous permettent de suggérer que l’ancêtre des chordés formait du tissue neurale au travers des mécanismes mis en évidence dans cet étude. Ces résultats nous permettent également de proposer de nouvelles études chez les vertébrés visant à établir un rôle putatif de la voie Activine/Nodal au cours de ce processus, rôle jusque la complètement inconnu<br>Neural induction is the process through which embryonic ectodermal cells become neural. Many studies on the mechanisms controlling this process have been made, but because of its complexity, many questions remain unanswered. In this thesis, I have focused my interest on the study of neural induction in an evolutionary context studying this process in the cephalochordate amphioxus, one of the closest relatives of vertebrates. I have highlighted that amphioxus, as vertebrates, possesses an organizer. I have demonstrated a conservation of the role of BMP and FGF signals in the induction of the epidermis and the regionalization of neural tissue respectively. However, in contrast to vertebrates, FGF signal does not appear to be a major player in neural induction. Instead, an important role of Activin/Nodal signaling pathway has been demonstrated. These results support, first, the conservation of several aspects of this mechanism in all chordates, and second, they suggest the involvement of the Activin/Nodal signaling in this process, something previously unknown in vertebrates. The phylogenetic position of amphioxus and the overall conservation of this process between cephalochordates and vertebrates allow us to suggest that the ancestor of chordates formed its neural tissue through mechanisms highlighted in this study. These results also allow us to propose new studies in vertebrates for establishing a putative role of the Activin/Nodal signaling during this process, a role previously completely unknown
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Millar, D. A. "Some aspects of the immunobiology of Saccoglossus ruber (Hemichordata) and Branchiostoma lanceolatum." Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638192.

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The work embodied in this thesis concerns the host defence mechanisms of the hemichordate, <i>Saccoglossus ruber</i> and the cephalochordate, <i>Branchiostoma lanceolatum</i>. Initially the cellular repsonses of these animals towards experimentally introduced foreign particles were examined. <i>S. ruber</i> possesses avidly phagocytic coelomocytes which were studied <i>in vitro</i> and <i>in vivo</i>, and shown by light and electron microscopy to be of a single morphological type. These coelomocytes probably originate from the coelomic lining, but autoradiography failed to substantiate this. The cellular response in <i>B. lanceolatum</i> towards wounding and subcutaneously injected bacteria was very limited. Even after 7 days, a relatively small number of coelomocytes accumulated at the site of injection. These coelomocytes contained phagocytosed bacteria and formed the beginning of nodule-like structures. In the majority of sections, the bacteria were observed surrounded by an unidentifiable amorphous material. Haemagglutinins and antibacterial factors were also detected in whole body homogenates of <i>S. ruber</i> and <i>B. lanceolatum</i>. The haemagglutinins from both animals were proteinaceous and functioned independently of Ca<SUP>++</SUP> and Mg<SUP>++</SUP>. The <i>S. ruber</i> agglutinin showed specificity for D-galactose containing carbohydrates, whereas no clear-cut carbohydrate specificity could be discerned with the <i>B. lanceolatum</i> agglutinin. The <i>S. ruber</i> agglutinin was also associated with the mucus covering the body surface, and the <i>B. lanceolatum</i> agglutinin with mucus in the pharynx. Antibacterial activity in <i>S. ruber</i> was strongest against natural bacterial isolates. The active factor, which may be a bromophenol, was heat stable, dialyzable, bactericidal in its mode of action and also associated with the body surface mucus. The <i>B. lanceolatum</i> antibacterial factor was bacteriostatic, probably proteinaceous, heat labile and operated over a wide temperature range. At a protein concentration above 5 mg ml<SUP>-1</SUP>, the antibacterial proteins aggregated and could be disassociated only at high pH. A role for these humoral factors in the defence systems of the experimental animals is discussed.
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Garstang, Myles Grant. "The evolution and regulation of the chordate ParaHox cluster." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/11788.

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The ParaHox cluster is the evolutionary sister of the Hox cluster. Like the Hox cluster, the ParaHox cluster is subject to complex regulatory phenomena such as collinearity. Despite the breakup of the ParaHox cluster within many animals, intact and collinear clusters have now been discovered within the chordate phyla in amphioxus and the vertebrates, and more recently within the hemichordates and echinoderms. The archetypal ParaHox cluster of amphioxus places it in a unique position in which to examine the regulatory mechanisms controlling ParaHox gene expression within the last common ancestor of chordates, and perhaps even the wider Deuterostomia. In this thesis, the genomic and regulatory landscape of the amphioxus ParaHox cluster is characterised in detail. New genomic and transcriptomic resources are used to better characterise the B.floridae ParaHox cluster and surrounding genomic region, and conserved non-coding regions and regulatory motifs are identified across the ParaHox cluster of three species of amphioxus. In conjunction with this, the impact of retrotransposition upon the ParaHox cluster is examined and analyses of transposable elements and the AmphiSCP1 retrogene reveal that the ParaHox cluster may be more insulated from outside influence than previously thought. Finally, the detailed analyses of a regulatory element upstream of AmphiGsx reveals conserved mechanisms regulating Gsx CNS expression within the chordates, and TCF/Lef is likely a direct regulator of AmphiGsx within the CNS. The work in this thesis makes use of new genomic and transcriptomic resources available for amphioxus to better characterise the genomic and regulatory landscape of the amphioxus ParaHox cluster, serving as a basis for the improved identification and characterisation of functional regulatory elements and conserved regulatory mechanisms. This work also highlights the potential of Ciona intestinalis as a ‘living test tube' to allow the detailed characterisation of amphioxus ParaHox regulatory elements.
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Dailey, Simon Christopher. "Evolutionary developmental and genomic insights from a tail regeneration transcriptome of the cephalochordate Branchiostoma lanceolatum." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/12608.

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Caccavale, Filomena. "Study of the evolutionary role of nitric oxide (NO) in the cephalochordate amphioxus, Branchiostoma lanceolatum." Thesis, Open University, 2018. http://oro.open.ac.uk/54738/.

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Nitric Oxide (NO) is a gaseous molecule that acts in a wide range of biological processes. NO can be produced by enzymatic and non-enzymatic pathways and, in this scenario, the enzyme Nitric Oxide Synthase (NOS) has a great importance for its exclusive role in <i>de novo</i> synthesis of NO. In the present study, the role of the NO in the embryonic development was investigated in the cephalochordate <i>Branchiostoma lanceolatum</i> (amphioxus) with the purpose of acquiring further knowledge on the ancestral role of animal <i>Nos</i> and the acquisition of new NO functions during evolution. Amphioxus has three different <i>Nos</i> genes (<i>NosA, NosB</i> and <i>NosC</i>) that are not orthologues of the three <i>Nos</i> of mammals (<i>NosI, NosII</i> and <i>NosIII</i>) deriving from an independent duplication occurred in the common ancestor of cephalochordates. The three amphioxus <i>Nos</i> genes showed a different temporal and spatial expression during development and a different susceptibility to be induced after immune stimulation. The study of the promoter regions of these genes can be very useful to identify possible diversities in regulation that can lead those peculiar expression features. In amphioxus larva, NO was mainly detected in the developing nervous system and in the pharyngeal area, before and after the mouth opening. The inhibition of NOS activity, and as consequence the enzymatic NO production, during amphioxus neurulation, resulted in the alteration of pharyngeal structures formation in the larvae, in particular opening of the mouth resulted compromised. Moreover, an alteration in larva locomotion was observed. Further studies will be necessary to reveal the exactly molecular mechanisms and the pathways in which II NO acts for establishment of the pharyngeal structures and the neuromuscular junctions early in development. For this purpose, a differential transcriptomic analysis of NOS-inhibited embryos was performed but the results are still very preliminary.
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Zieger, Elisabeth. "Roles of retinoic acid signaling in regulating nervous system development in the cephalochordate amphioxus (Branchiostoma lanceolatum)." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066075.

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Le système nerveux est responsable de l’interconnexion interne des animaux multicellulaires. Il leur permet en effet d’intégrer les activités physiologiques de leurs différentes composantes en une seule entité fonctionnelle, capable d’interagir avec son environnement. L’évolution et le développement des systèmes nerveux complexes comptent parmi les questions les plus fascinantes de la recherche en biologie. Afin de mettre en place une diversité de types de cellules neurales et de connexions neurales, les animaux métazoaires ne déploient qu’un nombre étonnamment réduit de signaux développementaux. C’est l’intermodulation dynamique de ces signaux qui va pouvoir induire un patron spatial d’identités et de comportements cellulaires distincts. L’acide rétinoïque (AR) est une petite molécule diffusible dérivée de la vitamine A qui contribue à la mise en place des axes du système nerveux central des vertébrés et est un régulateur crucial de la différentiation neuronale. D’autre part, il a été montré que les signaux à l’AR affectaient le phénotype de neurotransmetteurs exhibé par des sous-populations neuronales et jouent des rôles divers dans la morphogenèse du système nerveux périphérique issu des placodes crâniennes et des cellules des crêtes neurales. Néanmoins, bien que le rôle de l’AR dans la régionalisation du système nerveux central ait été étudié de manière extensive, nous en savons beaucoup moins au sujet de l’action de l’AR sur le développement du système nerveux périphérique, sur l’établissement des différentes identités de neurotransmetteurs, ou quant à comment ces fonctions ont évolué. Bien qu’initialement considéré comme spécifique aux vertébrés, un volume croissant de données indique désormais que l’AR serait impliqué dans le développement du système nerveux de divers taxons, tels que les cnidaires, les mollusques gastropodes ainsi que les cordés invertébrés. En particulier, l’amphioxus, céphalocordé dont l’évolution est lente, est connu pour posséder un système de signalisation à l’AR semblable à celui des vertébrés. Le génome de l’amphioxus présente un haut degré de conservation de sa synténie par rapport à celui des vertébrés et exhibe relativement peu de pertes ou de duplications indépendantes de ses gènes développementaux. Par conséquent, l’embryogenèse ainsi que la morphologie de l’amphioxus ressemble par bien des points à celles des vertébrés, ce qui facilite l’identification des traits ancestraux et dérivés et en fait donc un modèle approprié à la recherche comparative. Cette étude vise à fournir une description détaillée de différentes populations neurales au sein du système nerveux périphérique de l’amphioxus et d’explorer les rôles joués par l’AR dans ce processus. À cette fin, des analyses d’expression de gènes et d’immunohistochimie ont été utilisées, en vue d’identifier les différentes sous-populations de progéniteurs et les différents types de cellules neurales. De plus, les niveaux de signaux à l’AR ont été altérés pharmacologiquement à différents stades de développement de l’amphioxus, pour déterminer leurs effets sur la formation des populations neurales identifiées, ainsi que sur les patrons de prolifération et d’apoptose. Les résultats inclus dans ce travail révèlent la présence de différentes populations de cellules neurales chez l’amphioxus et mettent en lumière leur vraisemblable relation phylogénétique avec les structures leur correspondant chez les vertébrés. Par ailleurs, différents rôles contexte-dépendants de la signalisation à l’AR on été documentés, incluant la mise en place de frontières discrètes dans le système nerveux central et l’ectoderme de l’embryon d’amphioxus, et la régulation du développement des progéniteurs neuraux tardifs dans le système nerveux périphérique de manière spécifique à leur type cellulaire<br>The nervous system provides internal interconnection to multi-cellular animals. It enables them to integrate the physiological activities of their different components into one functional entity that can successfully interact with its environment. The evolution and development of complex nervous systems is one of the most fascinating questions of biological research. In order to generate a diversity of neural cell types and neural connections, metazoan animals deploy a surprisingly small number of instructive developmental signals, which crosstalk in a dynamic manner to induce a spatial pattern of cell identities and behaviors.Retinoic acid (RA) is a small diffusible signaling molecule derived from vitamin A that contributes to the axial patterning of the vertebrate central nervous system and functions as a crucial regulator of neuronal differentiation. Moreover, RA signals have been shown to affect the neurotransmitter phenotype of specific neuronal subsets and play distinct roles during the morphogenesis of the peripheral nervous system from cranial placodes and neural crest. However, while the role of RA signaling in the regionalization of the central nervous system has been extensively studied, much less is known about its actions in cranial placodes and neural crest derivatives, in the establishment of different neurotransmitter identities, or how these functions might have evolved.Albeit initially believed to be vertebrate-specific, a growing body of evidence now implicates RA signaling in the nervous system development of various distant taxa, such as cnidarians, gastropod mollusks and invertebrate chordates. In particular, the slow evolving cephalochordates, commonly called amphioxus, are known to possess a vertebrate-like RA signaling system. The amphioxus genome has retained a high degree of synteny with vertebrate genomes and exhibits relatively little losses or independent duplications of developmental genes. Accordingly, amphioxus embryogenesis and morphology also display remarkable similarity with vertebrates, which allows the identification of ancestral as well as newly derived traits and makes these animals attractive models for comparative research.This study aims at providing a detailed description of the development of different neural cell populations in the central and peripheral nervous system of amphioxus and explores the roles played by RA signaling during this process. To this end, gene expression analyses and immunohistochemistry were used, in order to identify distinct subsets of neural progenitors and neural cell types. Furthermore, RA signaling levels were manipulated pharmacologically at different stages of amphioxus development, to assess their effects on the formation of identified neural cell populations as well as on proliferation and apoptosis patterns. The results presented in this work reveal the presence of distinct neural cell populations in amphioxus and highlight their likely phylogenetic relationships with corresponding structures in other chordates. In addition, several context-dependent functions of RA signaling were documented, which include the generation of discrete boundaries in the central nervous system and ectoderm of amphioxus embryos as well as the cell type-specific regulation of late neural progenitor development in the peripheral nervous system. The observed roles of RA signaling in the amphioxus neural tube and peripheral nervous system correspond well to those reported for the vertebrate hindbrain and cranial placodes, supporting the current hypothesis of a close evolutionary relationship between these structures and suggesting that the involvement of RA signals in their development is a conserved feature of chordates
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9

Zieger, Elisabeth. "Roles of retinoic acid signaling in regulating nervous system development in the cephalochordate amphioxus (Branchiostoma lanceolatum)." Electronic Thesis or Diss., Paris 6, 2016. http://www.theses.fr/2016PA066075.

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Le système nerveux est responsable de l’interconnexion interne des animaux multicellulaires. Il leur permet en effet d’intégrer les activités physiologiques de leurs différentes composantes en une seule entité fonctionnelle, capable d’interagir avec son environnement. L’évolution et le développement des systèmes nerveux complexes comptent parmi les questions les plus fascinantes de la recherche en biologie. Afin de mettre en place une diversité de types de cellules neurales et de connexions neurales, les animaux métazoaires ne déploient qu’un nombre étonnamment réduit de signaux développementaux. C’est l’intermodulation dynamique de ces signaux qui va pouvoir induire un patron spatial d’identités et de comportements cellulaires distincts. L’acide rétinoïque (AR) est une petite molécule diffusible dérivée de la vitamine A qui contribue à la mise en place des axes du système nerveux central des vertébrés et est un régulateur crucial de la différentiation neuronale. D’autre part, il a été montré que les signaux à l’AR affectaient le phénotype de neurotransmetteurs exhibé par des sous-populations neuronales et jouent des rôles divers dans la morphogenèse du système nerveux périphérique issu des placodes crâniennes et des cellules des crêtes neurales. Néanmoins, bien que le rôle de l’AR dans la régionalisation du système nerveux central ait été étudié de manière extensive, nous en savons beaucoup moins au sujet de l’action de l’AR sur le développement du système nerveux périphérique, sur l’établissement des différentes identités de neurotransmetteurs, ou quant à comment ces fonctions ont évolué. Bien qu’initialement considéré comme spécifique aux vertébrés, un volume croissant de données indique désormais que l’AR serait impliqué dans le développement du système nerveux de divers taxons, tels que les cnidaires, les mollusques gastropodes ainsi que les cordés invertébrés. En particulier, l’amphioxus, céphalocordé dont l’évolution est lente, est connu pour posséder un système de signalisation à l’AR semblable à celui des vertébrés. Le génome de l’amphioxus présente un haut degré de conservation de sa synténie par rapport à celui des vertébrés et exhibe relativement peu de pertes ou de duplications indépendantes de ses gènes développementaux. Par conséquent, l’embryogenèse ainsi que la morphologie de l’amphioxus ressemble par bien des points à celles des vertébrés, ce qui facilite l’identification des traits ancestraux et dérivés et en fait donc un modèle approprié à la recherche comparative. Cette étude vise à fournir une description détaillée de différentes populations neurales au sein du système nerveux périphérique de l’amphioxus et d’explorer les rôles joués par l’AR dans ce processus. À cette fin, des analyses d’expression de gènes et d’immunohistochimie ont été utilisées, en vue d’identifier les différentes sous-populations de progéniteurs et les différents types de cellules neurales. De plus, les niveaux de signaux à l’AR ont été altérés pharmacologiquement à différents stades de développement de l’amphioxus, pour déterminer leurs effets sur la formation des populations neurales identifiées, ainsi que sur les patrons de prolifération et d’apoptose. Les résultats inclus dans ce travail révèlent la présence de différentes populations de cellules neurales chez l’amphioxus et mettent en lumière leur vraisemblable relation phylogénétique avec les structures leur correspondant chez les vertébrés. Par ailleurs, différents rôles contexte-dépendants de la signalisation à l’AR on été documentés, incluant la mise en place de frontières discrètes dans le système nerveux central et l’ectoderme de l’embryon d’amphioxus, et la régulation du développement des progéniteurs neuraux tardifs dans le système nerveux périphérique de manière spécifique à leur type cellulaire<br>The nervous system provides internal interconnection to multi-cellular animals. It enables them to integrate the physiological activities of their different components into one functional entity that can successfully interact with its environment. The evolution and development of complex nervous systems is one of the most fascinating questions of biological research. In order to generate a diversity of neural cell types and neural connections, metazoan animals deploy a surprisingly small number of instructive developmental signals, which crosstalk in a dynamic manner to induce a spatial pattern of cell identities and behaviors.Retinoic acid (RA) is a small diffusible signaling molecule derived from vitamin A that contributes to the axial patterning of the vertebrate central nervous system and functions as a crucial regulator of neuronal differentiation. Moreover, RA signals have been shown to affect the neurotransmitter phenotype of specific neuronal subsets and play distinct roles during the morphogenesis of the peripheral nervous system from cranial placodes and neural crest. However, while the role of RA signaling in the regionalization of the central nervous system has been extensively studied, much less is known about its actions in cranial placodes and neural crest derivatives, in the establishment of different neurotransmitter identities, or how these functions might have evolved.Albeit initially believed to be vertebrate-specific, a growing body of evidence now implicates RA signaling in the nervous system development of various distant taxa, such as cnidarians, gastropod mollusks and invertebrate chordates. In particular, the slow evolving cephalochordates, commonly called amphioxus, are known to possess a vertebrate-like RA signaling system. The amphioxus genome has retained a high degree of synteny with vertebrate genomes and exhibits relatively little losses or independent duplications of developmental genes. Accordingly, amphioxus embryogenesis and morphology also display remarkable similarity with vertebrates, which allows the identification of ancestral as well as newly derived traits and makes these animals attractive models for comparative research.This study aims at providing a detailed description of the development of different neural cell populations in the central and peripheral nervous system of amphioxus and explores the roles played by RA signaling during this process. To this end, gene expression analyses and immunohistochemistry were used, in order to identify distinct subsets of neural progenitors and neural cell types. Furthermore, RA signaling levels were manipulated pharmacologically at different stages of amphioxus development, to assess their effects on the formation of identified neural cell populations as well as on proliferation and apoptosis patterns. The results presented in this work reveal the presence of distinct neural cell populations in amphioxus and highlight their likely phylogenetic relationships with corresponding structures in other chordates. In addition, several context-dependent functions of RA signaling were documented, which include the generation of discrete boundaries in the central nervous system and ectoderm of amphioxus embryos as well as the cell type-specific regulation of late neural progenitor development in the peripheral nervous system. The observed roles of RA signaling in the amphioxus neural tube and peripheral nervous system correspond well to those reported for the vertebrate hindbrain and cranial placodes, supporting the current hypothesis of a close evolutionary relationship between these structures and suggesting that the involvement of RA signals in their development is a conserved feature of chordates
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10

Holland, Linda Zimmerman. "Evolution of the chordate body plan : amphioxus (Branchiostoma floridae) as a stand-in for the ancestral vertebrate /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035901.

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Books on the topic "Branchiostoma"

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Stach, Thomas. Microscopic anatomy of developmental stages of Branchiostoma lanceolatum (Cephalochordata, Chordata). Zoologische Forschungsinstitut und Museum Alexander Koenig, 2000.

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Book chapters on the topic "Branchiostoma"

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Gao, Zhan, and Shicui Zhang. "Cephalochordata: Branchiostoma." In Advances in Comparative Immunology. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76768-0_16.

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Holland, Linda Z., and Guang Li. "Laboratory Culture and Mutagenesis of Amphioxus (Branchiostoma floridae)." In Methods in Molecular Biology. Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0974-3_1.

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Le Petillon, Yann, Stéphanie Bertrand, and Héctor Escrivà. "Spawning Induction and Embryo Micromanipulation Protocols in the Amphioxus Branchiostoma lanceolatum." In Methods in Molecular Biology. Springer New York, 2019. http://dx.doi.org/10.1007/978-1-4939-9732-9_19.

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Zou, Yong-shui. "CONTRACTILE SYSTEM OF AMPHIOXUS (BRANCHIOSTOMA BELCHERI)." In Retrospect and Prospect of Protein Research. WORLD SCIENTIFIC, 1991. http://dx.doi.org/10.1142/9789814360425_0013.

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Conference papers on the topic "Branchiostoma"

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Smirnova, E. O., A. S. Okatova, N. V. Lantsova, A. M. Egorova, Y. Y. Toporkova, and A. N. Grechkin. "THE UNUSUAL ENZYME OF THE CYP74 CLAN OF EUROPEAN LANCELET." In XI МЕЖДУНАРОДНАЯ КОНФЕРЕНЦИЯ МОЛОДЫХ УЧЕНЫХ: БИОИНФОРМАТИКОВ, БИОТЕХНОЛОГОВ, БИОФИЗИКОВ, ВИРУСОЛОГОВ, МОЛЕКУЛЯРНЫХ БИОЛОГОВ И СПЕЦИАЛИСТОВ ФУНДАМЕНТАЛЬНОЙ МЕДИЦИНЫ. IPC NSU, 2024. https://doi.org/10.25205/978-5-4437-1691-6-271.

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The present work reports the detection and cloning of a new CYP74 clan gene of the European lancelet (Branchiostoma lanceolatum) and the biochemical characterization of the corresponding recombinant enzyme.
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Zhongbao Li, Jin Chen, and Yuanyu Cao. "Notice of Retraction: Genetic variation and differentiation of amphioxus Branchiostoma belcheri (gray) populations." In 2010 2nd Conference on Environmental Science and Information Application Technology (ESIAT 2010). IEEE, 2010. http://dx.doi.org/10.1109/esiat.2010.5568535.

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Zhongbao Li, Jin Chen, and Yuanyu Cao. "Notice of Retraction: Genetic diversity and conservation strategies of amphioxus Branchiostoma belcheri (gray) populations." In 2010 2nd Conference on Environmental Science and Information Application Technology (ESIAT 2010). IEEE, 2010. http://dx.doi.org/10.1109/esiat.2010.5568536.

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