Дисертації з теми "Marqueur microsatellite"
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Cochard, Benoît. "Etude de la diversité et du déséquilibre de liaison au sein de populations améliorées de palmier à huile (Elaeis guineensis Jacq. )." Montpellier SupAgro, 2009. http://www.theses.fr/2009NSAM0001.
Knapp, Jenny. "Caractérisation et validation du marqueur microsatellite multilocus répété en tandem EmsB pour la recherche de polymorphisme génétique chez Echinococcus multilocularis : application à l'étude de la transmission du parasite en Europe." Phd thesis, Université de Franche-Comté, 2008. http://tel.archives-ouvertes.fr/tel-00338957.
Avenot, Hervé. "Variabilité au sein de l'espèce fongique phytopathogène Alternaria brassicicola : analyse au niveau d'un marqueur sélectionné de type résistance aux fongicides et de marqueurs neutres de type microsatellites." Angers, 2005. http://www.theses.fr/2005ANGE0033.
Alternaria brassicicola causes blackspot disease of crucifers worldwide. This disease is seed-borne and responsible for important yield losses. Field isolates of A. Brassicicola highly resistant to dicarboximide and phenylpyrroles fungicides have been identified. These isolates are still pathogenic to host plants and most of them are more sensitive to osmotic stress than wild type strains. To elucidate the molecular basis of the osmosensitive and dicarboximide/phenylpyrrole-resistant phenotypes, an osmosensing histidine kinase gene AbNIK1 was isolated from a fungicide-sensitive isolate and its sequence compared with corresponding sequences from fungicide-resistant isolates. All the fungicide-resistant strains displaying a osmosensitive phenotype were found to have null mutations in the AbNIK1 gene. To investigate the effects of AbNIK1 null mutations on their fitness, these strains were inoculated on radish under field conditions. Quality controls of produced seeds revealed that null mutants are strongly affected in their competitivity towards wild type strains in the absence of selective pressure. In parallel, the genetic diversity within the species A. Brassicicola was estimated. Twelve polymorphic microsatellite loci were identified and used to analyze a population of strains with various geographic origins. In agreement with the lifestyle of this fungus (absence of sexual reproduction and seed transmission) a relatively weak polymorphism (3. 5 alleles per locus) and an absence of population structuration were observed
Iquira, Elmer. "Évaluation de la diversité génétique chez deux collections de soja à l'aide de marqueurs microsatellites." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25896/25896.pdf.
Queney, Guillaume. "Histoire des populations et organisation sociale du lapin européen (Oryctolagus cuniculus) à travers l'étude de marqueurs microsatellites." Paris 7, 2000. http://www.theses.fr/2000PA077192.
Roustan, Pau. "Contribution à l'élaboration de la carte génétique du chromosome X humain : caractérisation de nouveaux marqueurs génétiques du type microsatellite." Toulouse 3, 1993. http://www.theses.fr/1993TOU30236.
WEINMAYR, GUDRUN. "Apports des marqueurs microsatellites a l'etude de la dispersion reelle en manche d'especes d'annelides polychetes a cycle benthopelagique." Paris 6, 1999. http://www.theses.fr/1999PA066530.
Picaud, Dorothée. "Phylogéographie du phoque commun (Phoca vitulina concolor) dans l'Atlantique nord-ouest utilisation de marqueurs microsatellites et de l'ADN mitochondrial /." Thèse, [Rimouski, Québec] : Université du Québec à Rimouski, 2008.
Titre de l'écran-titre (visionné le 30 juin 2008). Mémoire présenté à l'Université du Québec à Rimouski comme exigence partielle du programme de maîtrise en océanographie. CaQRU CaQRU Comprend des réf. bibliogr.: (f. 69-77). Publié aussi en version papier. CaQRU
Valière, Nathaniel. "Amélioration et optimisation des méthodes non-invasives et des marqueurs microsatellites en biologie des populations et de la conservation." Lyon 1, 2002. http://www.theses.fr/2002LYO10075.
Roussel, Valérie. "Analyse de la diversité et de la structuration génétique d'une collection de blés tendres (Triticum aestivum) à l'aide de marqueurs agro-morphologiques, biochimiques et moléculaires." Rennes, Agrocampus, 2005. http://www.theses.fr/2005NSARC079.
Genetical resources centre at INRA Clermont-Ferrand groups about 10 000 bread wheat accessions originating from all over the world and maintained using the ex-situ technique. To proceed an efficient management of these resources one of the aims o this centre is to create one or several core collections, to be able to use in the best way the genetic diversity presented in the entire collection. So, a preliminary description of this collection was necessary. The aim of this thesis was to evidence possible genetic structuration in a sub-collection composed with about 4 000 accessions representing all the countries presented in the whole collection, and all the periods or registratrions. This work was processed tat three different geographical levels. First a study was done using a sub-collection of 559 french bread wheat accessions to analyse a possible temporal structuration linked to the registration period. Three different markers were used (agro-morphologic, molecular and biochemical) and the structurations obtained wre quite similar. All the markers evidenced a nearness between landraces and old varieties and a separation of the most recent wheats in the 70ies for agro-morphological traits and molecular markers, and in the 80ies for biochimecal markers. The separation observed in the 70ies comes probably from the introduction at the early 60ies of foreign genitors possessing dwarf genes, while the separation observed in the 80ies for biochemical markers indicates the new interest for the quality criteria in selection at this time
Bergeron, Nathaël. "Distribution de l'épifaune associée à l'aquaculture de moule et estimation du flux génique de Mytilus edulis à l'aide de marqueurs microsatellites." Thèse, [Rimouski, Québec] : Université du Québec à Rimouski, 2005.
Titre de lʹécran-titre (visionné le 1er septembre 2006). Mémoire présenté à l'Université du Québec à Rimouski comme exigence partielle du programme de maîtrise en gestion de la faune et de ses habitats. CaQRU CaQRU Bibliogr.: f. 40-46. Paraît aussi en éd. imprimée. CaQRU
Wattier, Rémi. "Recherche de marqueurs genetiques microsatellites et analyse de la structure genetique des populations chez une algue rouge haplo-diploide, gracilaria gracilis." Paris 6, 1998. http://www.theses.fr/1998PA066365.
Rivet, Jacqueline. "Etude des marqueurs de progression tumorale dans les cancers de l'appareil urinaire de l' adulte." Paris 7, 2008. http://www.theses.fr/2008PA077023.
Renal cell cancers are highly vascularised. We quantified VEGF and showed that its expression is correlated to prognostic factors in these tumors. Using laser microdissection, we sampled separately tumor cells and stromal cells. We showed that VEGF mRNA and VEGFR-1 mRNA (but not VEGFR-2 mRNA) levels were higher in tumor and stromal cells than in non tumor cells, suggesting that both tumor and stromal cells contribute to VEGF and VEGFR-1 overexpression. Tumor growth may be under the control of the VEGFA/EGFR-1 pathway rather than the VEGFA/EGFR-2 pathway. Moreover, VEGF and VEGFR-1 colocalization in tumor cells and in stromal cells suggests autocrine and paracrine interactions. Necrosis may be a prognostic factor in renal cancer but this is still controversial. Quantification of necrosis on tissue sections using digital microscopy has proved to be highly reproducible as compared to conventional microscopy. Digital microscopy could therefore become an important tool for the quantitation of necrosis after antiangiogenic treatments. Allelic losses and microsatellite instability (MSI+) have been analysed in tumors of the upper urinary tract. MS was observed in over 50% of tumors, while only 3% of bladder tumors were MSI+. Urothelial tumors of the upper urinary tract are therefore biologically different from those of the lower urinary tract
Dayo, Guiguigbaza-Kossigan. "Recherche de marqueurs génétiques associés à la tolérance et/ou sensibilité des bovins aux trypanosomoses africaines." Montpellier 2, 2009. http://www.theses.fr/2009MON20167.
This thesis aimed at identifying genetic markers associated with tolerance / sensitivity of cattle to African trypanosomosis. Association studies between microsatellite markers and trypanotolerance phenotype (anaemia control) were performed on a crossbred Baoule/zebu peul cattle population in natural conditions in south-western Burkina Faso. For genotyping, we used microsatellite markers located in four QTL (Quantitative Trait Loci) regions previously identified as related to anaemia or parasitaemia control in N'Dama / Boran zebu crossbred population. The linkage disequilibrium (LD) was estimated with D', r' and χ'² measures from genotype and haplotype data. Results showed high genetic variability in terms of mean number of alleles per locus, heterozygosities and the LD extends over shorter distances than what has been observed in selected European bovine populations. The ANOVA test showed that an allele of MNB-42 microsatellite marker was significantly associated with this phenotype (FDR = 0. 011). The search for signatures of selection performed on African trypanotolerant taurine, African trypanosusceptible zebu and European trypanosusceptible taurine, using tests based on the reduction of the microsatellite markers variability between trypanotolerant cattle and trypanosusceptible cattle in one hand and tests based on genetic differentiation on the other hand, allowed the detection of outliers (markers that deviate from the assumption of neutral evolution) that are probably linked to selected loci. Our results support the hypothesis that natural selection contributed to the development of trypanotolerance in West African taurine populations
Roy, Marc-André. "Caractéristiques génétiques des principaux gisements de pétoncle géant (Placopecten magellanicus) à l'échelle du golfe du Saint-Laurent analyse à l'aide de marqueurs microsatellites /." Thèse, [Rimouski, Québec] : Université du Québec à Rimouski, 2005.
Mémoire présenté à l'Université du Québec à Rimouski comme exigence partielle du programme de maîtrise en océanographie. Comprend un résumé. Titre de l'écran-titre (visionné le 29 juin 2006). CaQRU CaQRU CaQRU Bibliogr.: f. [106]-121. Parait aussi en éd. imprimée. CaQRU
Meyer, Lucie. "The annual ragweeds (Ambrosia artemisiifolia L. - Ambrosia trifida L.) : adaptive response to chemical weeding and population genetics in agricultural environments." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCK005.
The first aim of this work was to investigate the risk for the evolution of resistance to acetolactate synthase inhibitor (ALS) herbicides in the common ragweed (Ambrosia artemisiifolia L.) through four points: (i) the selection pressure (effectiveness of a range of ALS inhibitor herbicides), (ii) the adaptive response of Ambrosia artemisiifolia (recurrent selection experiment), (iii) a resistance monitoring in fields in France, and (iv) the investigation of the mechanisms underlying herbicide resistance (target-site (TSR) and non-target-site resistance (NTSR) using transcriptomic analyses). The second aim was to study the connectivity of A. artemisiifolia populations in agricultural landscapes using microsatellite markers developed during this work, to determine factors that could facilitate the spread of this invasive weed species and the spread of herbicide resistance.In regards to herbicide resistance:-The sensitivity of A. artemisiifolia to ALS-inhibiting herbicides is variable between active ingredients.-Plants that survived the French maximum authorized field rate and higher rates of metsulfuron were selected to implement a recurrent breeding program. After two selection cycles, the resistance level to metsulfuron increased and resistance to imazamox and tribenuron emerged.-Three cases of imazamox resistance were identified in the field, including two cases of pure NTSR and one case of TSR - NTSR coexistence.-A transcriptome for A. artemisiifolia, AMBELbase, was generated using the PacBio sequencing technology to search for genes involved in NTSR mechanisms (RNAseq approach). 62 candidate contigs were identified including ABC transporters, cytochromes P450 and glutathione S-transferases known to be involved in the degradation of herbicides.In regards to population connectivity:-26 microsatellite markers were developed and revealed high genetic variability. Genetic structuring has been studied on a large scale for populations of A. artemisiifolia from Europe (invasion range) and North America (native range).-On a finer scale (agricultural landscape), the genetic structure of populations was influenced by colonization events. Migration events detected among the areas colonized by A. artemisiifolia suggested moderate pollen/seed flows and connectivity at the farmland scale. In agricultural environments, herbicide resistant alleles could be easily spread among neighbouring populations via pollen flow, and also at longer distances via seed dispersal. Human-related activities play a major role in the dispersal of seeds (agricultural machinery, contaminated seed lots, etc.).-The mating system analysis confirmed that A. artemisiifolia is an obligate outcrossing species which leads to important intra- and inter-population gene flow.The knowledge acquired during this work may help to foster the development of better management strategies to effectively control A. artemisiifolia to limit its spread, such as:-Diversified weed control strategies: combination of mechanical (including false-seed) and chemical weeding (diversification of herbicide modes of action).-Longer diversified crop rotations including more winter crops and/or cover and competitive crops to break the life cycle of A. artemisiifolia.These knowledge may also be used to better control of another weed species of the genus Ambrosia, Ambrosia trifida L
Barnetche, Thomas. "Enjeux méthodologiques de l'analyse de marqueurs génétiques dans les études d'association de maladies multifactorielles : application à la polyarthrite rhumatoïde." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/43/.
Genetics of multifactorial diseases raise new methodological challenges because of complex pathophysiological mechanisms, and our technic capability to analyse genomic data. This PhD work aims at highlighting the main methodological features of genetic studies dealing with multifactorial diseases, within the example of rheumatoid arthritis (RA). RA is the most frequent chronic inflammatory rheumatism, and is characterized by synovial joints inflammation and articular destructions. After a review of methodological strategies in genetics of complex diseases, two main questions were addressed. First, a case-control study was performed to search a new susceptibility gene inside the HLA region, and independent from HLA-DRB1. This work also warranted the set up of a new nomenclature of HLA microsatellite markers. Second, a meta-analysis on a worldwide sample of RA patients, caucasoids and non-caucasoids, was conducted to investigate the relevance of the new HLA-DRB1 allele's classification in terms of RA susceptibility. PATIENTS AND METHODS: The first case-control study, with 170 RA patients and 282 healthy controls, tried to identify new genetic markers, associated with susceptibility and / or severity of RA, within the MHC region, using microsatellite markers. Then, a meta-analysis on RA patient's samples from the XIIIth International Histocompatibility Workshop investigated the new SE coding allele's classification on caucasoids and non-caucasoids patients. RESULTS: The study HLA microsatellites/RA highlighted a significant association between HLA-A*02/D6S265*136 and susceptibility to RA, association which is independent from HLA-DRB1 gene effect. No association was found with RA severity. Results from the meta-analysis permit to confirm the relevance of the new SE allele's classification, which differentiates susceptibility and protective alleles
Molinier, Virginie. "Diversité génétique et aromatique de la truffe de Bourgogne." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS021/document.
Truffles are ectomycorrhizal Ascomycota fungi belonging to the Tuberaceae family and more specifically to the Tuber genus. More than thirty Tuber species are currently described in Europe. In this thesis, we specifically focused on the Tuber aestivum-uncinatum model. This truffle is commonly called "Burgundy Truffle" and has a gastronomic and cultural interest.The first part of this thesis focused on the taxonomic status of the Burgundy truffle (Tuber uncinatum). For this, we used a multi-marker approach combining several genetic markers commonly used at the interspecific scale. Our analyses showed that the two taxa, Tuber aestivum (summer truffle) and Tuber uncinatum are conspecific.In the second part, we addressed the genetic diversity of Tuber aestivum. To do this, we firstly developed specific microsatellite markers by "direct shotgun pyrosequencing". This method has allowed the development of 15 polymorphic microsatellite markers. Then, we used those markers to genotype individuals from different European locations. We have identified four differentiated subpopulations that not correspond, for the majority, to a geographical distribution. However, one cluster differs from the others by its location (south of France) and its genetic characteristics (presence of rare alleles). These preliminary results may indicate the existence of a particular ecotype attached to a southern ecology: Tuber aestivum sensu stricto.We were then interested, in the third part of this thesis, to the aromatic diversity of Tuber aestivum at a local scale. Our results highlight the existence of a moderate differentiation between individuals from a natural truffle orchard and individuals from planted orchard. From one season to another, genotypic stability was observed. Only C8 volatile organic compounds seem to be related to the genotypes.In the last part, we analyzed harvesting data, over more than thirty years, from an hazelnut truffle orchard initially inoculated by Tuber melanosporum. Through simple statistical analyzes, we noted changes in both quantity and weight of truffles harvested according to the seasons and hazelnut trees. It appears that Tuber aestivum rapidly replaced Tuber melanosporum (in three years). The disappearance of Tuber melanosporum can probably be explained by the canopy closure; Tuber melanosporum not appreciating excessive shading
Siret, René. "Etude du polymorphisme génétique de la vigne cultivée (vitis vinifera L. ) à l'aide de marqueurs microsatellites : application à la caractérisation des cépages dans les vins." Montpellier 1, 2001. http://www.theses.fr/2001MON13502.
Devaux, Céline. "Modélisation et estimation de la dispersion efficace du pollen de colza à longue distance, dans un paysage agricole et dans un champ." Paris 11, 2006. http://www.theses.fr/2006PA112173.
This study aimed at building spatially explicit models of oilseed rape pollen dispersal to estimate dispersal kernels and conclude on the proportion of long-distance pollination. These dispersal kernels, that describe the probability of a pollen grain to fertilize a plant at a given distance, were estimated using data collected in a french production area (selommes, loir-et-cher) of 100 km² and containing 170 oilseed rape fields. First male-sterile plants were scattered in the study area to collect pollen grains. Then the genotypes of these pollen grains were retrieved using microsatellite markers. Dispersal kernels were estimated by maximising the likelihood of the genetic data under a mating model adapted to cultivated species. Results of this study showed that (1) sampled pollen clouds were diverse and differentiated, (2) these pollen clouds originated from close and distant fields (several hundred meters) and (3) half of the pollen clouds originated from pollen sources whose position and composition could not be precisely determined. The best-fitted dispersal kernel in this study (geometric) predicts much more long-distance pollination than the exponential functions that are commonly used and than dispersal kernels that were previously fitted within a field. The best-fitted kernel here was then (partially) validated by using it to predict cross-pollination rates observed in twelve canadian sites consisting of commercial fields of several hundred hectares
Charrier, Olivia. "Histoire biogéographique et système de reproduction de Rhododendron ferrugineum dans les Pyrénées." Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0034/document.
Recent global changes affect the physiology, distribution and phenology of species, also they impact population dynamic and interactions among species. Plantpollinators interactions are particularly threated by global changes and perturbations of these interactions may lead to important changes in plant mating system. In this context of globalchanges, we determined the pollinator assemblages of Rhododendron ferrugineum and howthe variability of their efficiencies affects the mating system. We also studied thebiogeographic history of R. ferrugineum and how it responds to past climatic changes.We have shown that R. ferrugineum is visited by a large variety of insects. Visitorassemblages efficiency varied along environmental gradients but did not seem to impact themating system of R. ferrugineum. This species presents a mixed mating system, indeed it isable to self-fecundate but high levels of inbreeding depression are limiting the development of self-fecundate descendants. High levels of inbreeding depression maintain high genetic diversity in the Pyrenees. Also, it did not allow the evolution of selfing and maintain a mixed mating system. The ability to self-fecundate may favor the colonization of new habitats.During the last glaciation, R. ferrugineum survived in large lowland refugia and in nunataks at high altitude. Some marginal populations present a high level of selfing (FIS> 0) and low genetic diversity. This genetic pattern is consistent with foundation events and loss of genetic diversity and heterozygosity along colonization rods. Our data suggest that inbreeding depression in these populations should have been low and the reproductive assurance played akey role in the establishment of these populations
Laliberté, Hugo Yann. "Caractérisation de la variabilité et des distances génétiques des bovins de race Canadienne, Suisse-Brune et Holstein à l'aide du polymorphisme des caséines et de marqueurs microsatellites." Sherbrooke : Université de Sherbrooke, 1998.
Aurelle, Didier. "Contacts secondaires naturels et artificiels chez la truite commune (Salmo trutta, L. ) des Pyrénées occidentales françqises : utilisation de marqueurs microsatellites pour la distinction de taxons faiblement différenciés." Montpellier 2, 1999. http://www.theses.fr/1999MON20087.
Laliberté, Hugo Yann. "Caractérisation de la variabilité et des distances génétiques des bovins de race Canadienne, Suisse-Brune et Holstein à l'aide du polymorphisme des caséines et de marqueurs microsatellites." Mémoire, Université de Sherbrooke, 1998. http://savoirs.usherbrooke.ca/handle/11143/4392.
Simard, Frédéric. "Variabilité génétique et flux de gènes chez les moustiques anophèles arabiensis et anophèles gambiae, vecteurs du paludisme en Afrique. Apport des loci microsatellites." Nancy 1, 1999. http://docnum.univ-lorraine.fr/public/SCD_T_1999_0147_SIMARD.pdf.
Baudry, Emmanuelle. "Cartographie genetique du genome de l'abeille domestique (apis mellifera l. ) a l'aide de marqueurs microsatellites, recherche de locus controlant la variation de caracteres quantitatifs et localisation de centromeres." Paris 11, 1999. http://www.theses.fr/1999PA112307.
Collin-Chavagnac, Delphine. "Carcinomes urothéliaux de la vessie : apport de l’analyse dans les cellules du culot urinaire de huit marqueurs microsatellites et de l’hyperméthylation de promoteurs de cinq gènes suppresseurs de tumeur." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10307.
On the basis of clinical and pathological criteria, the evolution of superficial bladder tumours (SBT) is unpredictable. Currently, no marker exists permitting the identification of tumours with high potential for recurrence and progression to more aggressive forms. Firstly, we looked for loss of heterozygosity (LOH) at microsatellite polymorphisms in the bladder cells of 127 patients, with the aim of identifying a marker potentially useful in 1) diagnosis and prognosis and 2) the monitoring of patients following trans-urethral resection. Compared to urine cytology, the sensitivity of LOH detection was significantly higher for SBT. The presence of LOH at TP53 and markers of chromosome 9p was associated with an increased risk of recurrence. Among the patients who relapsed, results of LOH analysis were positive in 78% of urine samples, 20% of which were positive before the relapse was detected by cystoscopy. Secondly, we developed a technique for the rapid and quantitative urinary analysis of patterns of promoter methylation of 5 tumour suppressor genes. The promising results (sensitivity of 62%) of the qPCR-HRM correlate well with the gold standard and could be improved by expanding the panel of genes studied. Analysis of genetic and epigenetic alterations improves the understanding of mechanisms of carcinogenesis in urothelial carcinomas. These alterations could be used as diagnostic and prognostic markers. Molecular biology could therefore prove useful in the management of this pathology
Estoup, Arnaud. "Apport des marqueurs microsatellites pour l'etude de la variabilite genetique chez deux insectes sociaux, l'abeille domestique (apis mellifera l. ) et le bourdon (bombus terrestris latreille) : de la colonie a l'espece." Paris 11, 1995. http://www.theses.fr/1995PA112032.
Laliberté, Hugo Yann. "Caractérisation de la variabilité et des distances génétiques des bovins de race Canadienne, Suisse-Brune et Holstein à l'aide du polymorphisme des caséines et des marqueures microsatellites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0001/MQ40599.pdf.
Zhang, Liyi. "Etude de la portabilité de marqueurs microsatellites issus d'EST de blé tendre (T. aestivum) ou de riz (O. sativa) vers des espèces apparentées et évaluation de leur intérêt pour la structuration des ressources génétiques chez les graminées." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00689788.
Alfonsi, Eric. "Le marsouin commun et le phoque gris en mer d'Iroise et le long de la façade Atlantique française : génétique des populations et modifications de l'écosystème." Thesis, Brest, 2013. http://www.theses.fr/2013BRES0073/document.
Marine mammals are key species of ecosystems. They undergo numerous environment modifications which require conservation plans. For that, the knowledge about population structure is primary. Studies of population genetic were led about two flagship species of the Iroise Sea. For the harbour porpoise, a specie who know a return along french coasts, our works unexpectedly show this return is the result of two movements and an hybridization between individuals of the Iberia population and those of North Europe population. These movements are, probably, linked to modifications of prey's availability caused by environment changes. For the grey seal, our works show a great genetic richness, with an ancestral structure for the mitochondrial control region and a panmixia for the microsatellites loci, which are signs of a population at the scale of Celtic Shelf. A differentiation was observed between the stranding years even and odd and a possible genetic signal of individuals from another population. Finally we led a pilot study for marine mammal genetic biodiversity observatory with the DNA barcoding technique. This study shows this observatory may be a relevant and innovative means to follow the marine mammal biology. All our results bring new information about ecosystem variations and are a help for the establishment of conservation strategy
Boucher, Annie Christine. "Caractérisation de la structure génétique des populations québécoises du nématode doré (Globodera rostochiensis) et développement d'exsudats racinaires de pomme de terre." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6572.
Masson, Séverine. "Continuité écologique et conservation de la diversité génétique et écotype d’un grand migrateur (Salmo trutta L.)." Thesis, Pau, 2016. http://www.theses.fr/2016PAUU3031/document.
Dispersal, characterized by the movements of individuals in space and time leading to gene flows, allows populations to connect. Understanding factors shaping gene flow and population structure is vital to improve management and conservation practices of species. Those characterized by a partial anadromy, such as brown trout (Salmo trutta L.), are models of choice to study the role of ecotypic and behavioral diversity, under anthropic activities on population functioning. By using population genetics, this theses proposes to analyse population structure of brown trout in the Bay of Biscay, but also to determine the combined influence of sea trout dispersal, its reproductive behavior, and anthropic activities (stocking, transport of spawners) on their functioning. This thesis also addresses the contribution of brown trout populations (natal origin) on sea trout stock captured by professional fisheries, on the same study site, by coupling population genetics and otolith microchemistry. Results show a strong hierarchical structure of Brown trout population with seven distinct population detected in Adour basin. This seems to be explained a high site fidelity movement of sea trout together with a directional movement of sea trout from South (Spain) to North. This directional movement did not result into effective dispersal (i.e. movement followed by reproduction). Furthermore, a limited contemporary impact of stocking on genetic structure of wild population is observed. A few cases of inter-population gene flow detected seems to be explained by wild population management, particularly transport of spawners. The majority of sea trout captured by professional fisheries come from Gave d’Oloron and few from Nives and Gave de Pau. The reason is that Gave de Pau is impacted by migration barriers. And also that sea trout from Nives have phenotypic differences (smaller length) from sea trout originated from gaves. This suggest a differentiation of this population and can explained that professional fisheries capture them in smaller proportion.On the other hand, this thesis have been shown the difficulties to assign natal origin by using genetics when population are closed genetically. This confirm the usefulness to coupling population genetics and otolith microchemistry together to assign individuals to their natal origin at a finer scale than basin.Results obtained during these three years of thesis have made it possible the determination of distinct populations one of which contribute in majority of professional fisheries activities. These populations can be considered like potential management units (MUs) which could serve as basis in the elaboration of conservation and management plans. The better understanding of brown trout biology and functioning, and the impact of anthropic activities on population structure, obtained in this thesis, can also improve the decision-making of local managers for brown trout population conservation and management
GUYOMARCIH, HELENE. "Developpement de marqueurs microsatellites a partir de triticum tauschii. Application a l'evolution des genomes du genre triticum et a la recherche de qtl de qualite technologique en panification chez le ble tendre (triticum aestivum l. )." Clermont-Ferrand 2, 2000. http://www.theses.fr/2000CLF22243.
Flahauw, Emilie. "Caractérisation génétique de l'effort reproducteur de l'huitre creuse, Crassostrea gigas, dans le cadre des mortalités estivales de juvéniles : approche QTL." Thesis, La Rochelle, 2013. http://www.theses.fr/2013LAROS406/document.
The Pacific oyster, Crassostrea gigas, is a major aquacultured species whose production represents an economic interest at worldwide, european and french levels. However, this species undergoes summer mortalities recorded from the beginning of the 20th century and, since 2008, this phenomenon increased and threatens mainly juvenile oysters. Aquaculture production of oysters suffers consequences of mass mortalities, that’s why this phenomenon has been studied for many years. In France, the bacterium Vibrio splendidus and the Ostreid virus Herpes Virus 1 (OsHV-1) are often associated with mass mortality outbreaks of juveniles oysters and it was demonstrated that selected individuals for resistance to summer mortality were able to slow the increasing in viral load OsHV-1 in their tissues and then to decline it. These same individuals also present a lighter reproductive effort than individuals selected for their sensitivity to summer mortality. In this context, this study aimed to improve the knowledge of genetic architecture of reproduction of C. gigas by identifying some regions of the genome called QTLs (Quantitative Trait Loci) involved in reproductive effort and highlighting possible genetic relationships between reproduction and survival; QTLs involved in survival being already detected. To characterize the reproductive effort, it was necessary to develop a set of new tools. From a biological point of view, 21 F2 families were produced from lines selected for their contrasting response to summer mortality. From a molecular point of view, new SNPs (Single NucleotidePolymorphism) were developed to increase density of the genetic map already available for C. gigas. On a technical point of view, Magnetic Resonance Imaging (MRI) allowed to observe the gametogenesis of 300 individuals of the same family F2 during eight sessions over two years while previous studies were limited to a one-time observation because of the conventional methods of observation of gametogenesis leading necessarily to the death of the animals. A strong correlation was found between observations by MRI and observations by the conventional method of histology. In addition to the estimation of gonadic index (index traditionally used to characterize there productive effort), MRI also revealed individual variations in kinetics of gametogenesis and differences between males and females, the sex being identifiable on MRI images. In parallel, 300 individuals from two F2 families were sacrificed to estimate the gonadic index by histology. This approach enabled the detection of QTLs involved in many gametogenesis traits. Individuals from the three families characterized for F2 reproductive effort were characterized for survival during a summer mortality outbreak. This study was able to detect QTLs involved in the trait "survival". These QTLs correspond to some of those detected in a previous study. In addition, these QTLs are often collocated with QTLs involved in reproductive effort. Although there production of the Pacific oyster is a complex trait to follow, the new tools used in this thesis allowed acquiring new knowledges. The sequencing of genome of Crassostrea gigas and Next-Generation Sequencing technologies may be able to help to refine the detected QTL regions
Naino, Jika Abdel Kader. "Flux de gènes et évolution des ressources génétiques du mil (Pennisetum glaucum) dans le Bassin du Lac Tchad : rôle de la diversité socio-culturelle." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS180/document.
The resilience of sub-Saharan farming systems to environmental and socioeconomic disturbances is partly based on the maintenance of agro-biodiversity, but also on preserving the right for farmers to reproduce and freely exchange seeds and related knowledge. However, few data are actually available on effective seed flow and on mechanisms modulating gene flow and genetic introgression between landraces grown in Sahelian farming systems. For pearl millet especially, there are only very few data on the relationship between diversity of this crop on the one hand and the socio-cultural diversity of farmers on the other hand. In the first part of my thesis, I was interested in assessing a potential relationship between ethnolinguistic diversity and population genetic structure of pearl millet in the Lake Chad Basin. Analysis of molecular polymorphisms suggests the existence of social barrier to seed flow among ethnolinguistic groups. However, these barriers are not sufficient to prevent genetic introgression between pearl millet populations cultivated by farmers belonging to different ethno-linguistic groups. In the second chapter, I focused on the role of local adaptation on gene flow. The results led me to propose the hypothesis that gene flow between early and late landraces are higher in the northern regions where rainfall is weak. Finally in the third part, I have quantified the biochemical compound of pearl millet seeds belonging to different varieties that show different uses or culinary preferences among farmers belonging to different ethnolingiuistic groups. I used a combined approach of proteomics and metabolics. Among the 1072 protein spots quantified only 7 distinguish the very photoperiodic non photoperiodic landrace. Metabolomics data suggest the presence of fungi, possibly endophytes, in some of the samples analyzed
Ndiade, Bourobou Dyana. "Dynamique spatiale et temporelle de la diversité génétique d’une espèce rare en Afrique Centrale : baillonella toxisperma Pierre (le Moabi)." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20045/document.
If genetic diversity patterns of gregarious rainforest forest trees are well known, few knowledges are available about low density tree species. Does those last one follow the same genetic distribution pattern? Which biotic and abiotic factors underline the spatial structure and evolution of the genetic diversity of such species? In order to improve the knowledge of the biology of such species, we have propose through nuclear microsatellite(nuc) and chlorosplastic (cp) markers to (i) analyse the reproductive system of a low density tree species, (ii) assess its dispersal capacity through seeds and pollen, and finally to (iii) describe the spatial genetic structure at a fine and large scale. We have addressed those questions with Baillonella toxisperma Pierre (commonly named Moabi), a commercial tree of many uses, known to be rare (1 ind/15ha à 20 ha) and distributed through different ecologicals areas of Congo basin. Three main results rise from our study: (i) Despite a strong isolation of the adults, B. toxisperma has a dominant allogamous reproductive system (tm ≈ 98%) with a reduce rate of self-pollination (1- tm< 3%) which is probably due to occurrence of protandry. (ii) As expected in the case of low density trees, the spatial statistic (Sp) of the fine spatial genetic structure is very low [Spnuc = 0.003 ; Spcp = 0.015]. Those reflected a very high gene flow mediated through pollen [σp = 9.8 km à 10.8 km] and seeds [σs = 4.0 km à 6.3 km], that probably mediated by efficient dispersal vectors like bats, human and elephant. At a large scale, a phylogenetic signal has been detected between individuals located in both side of the thermic equator, mainly between those from the block forest of Cameroon and Gabon [RST = 0.313 > RSTp = 0.115, P < 0.001]. Two discretes genetics units from the Gabon block forest which separate individuals of the West coastal forests from the lowland forest ones (in the inland) have also been detected and showed a moderate genetic differentiation [FST = 0.068, P < 0.001]. The genetic differentiation between these three units could be explained by a geographical isolation during past climatic disturbances in the African rainforest, occurred in the Pleistocene and Holocene, and which will be still maintained up to date by a reproductive isolation caused by flowering asynchrony periods among individuals. The occurrence of these three genetic units suggests a biogeographical repartition of B. toxisperma in the Congo basin that is mainly due to the past and current climate. Our conclusions may lead to implement conservation strategies and sustainable management programm for biodiversity in Central Africa
Ewedje, Eben-Ezer. "Biologie de la reproduction, phylogéographie et diversité de l'arbre à beurre Pentadesma butyracea Sabine, Clusiaceae: implications pour sa conservation au Bénin." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209647.
Le but de ce travail est d’acquérir les connaissances requises pour la conservation et la gestion durable des ressources génétiques de l’espèce. Trois objectifs ont été définis :(i) étudier la phylogéographie de l’espèce, (ii) étudier sa variabilité morphologique et génétique au Bénin et (iii) caractériser sa biologie de reproduction. En amont de ces travaux, nous avons développé onze marqueurs microsatellites nucléaires chez P. butyracea (chapitre 2). Ils ont été utilisés pour l’étude de la phylogéographie et la diversité génétique de P. butyracea (chapitres 3 et 5), ainsi que pour étudier la dépression de consanguinité et les paramètres de son système de reproduction (chapitre 7).
La caractérisation de la répartition spatiale des lignées génétiques de régions intergéniques de l’ADN chloroplastique et de l’ADN ribosomal (ITS) a détecté deux lignées génétiques allopatriques entre le Haut et le Bas-Guinéen, indiquant une forte différenciation génétique et un signal phylogéographique. L’analyse des microsatellites détecte trois pools géniques correspondant aux trois régions étudiées (Haute Guinée, Dahomey Gap et Basse Guinée). La diversité génétique est faible dans le Dahomey Gap, modérée dans le Haut-Guinéen et élevée dans le Bas-Guinéen. Ces résultats indiquent une séparation très ancienne des populations d’Afrique centrale et d’Afrique de l’ouest, alors que celles du Dahomey Gap pourraient résulter des forêts denses humides de l’Afrique de l’ouest lors de la période Holocène humide africaine. Dans ce couloir sec, les populations ont subi une forte dérive génétique, potentiellement due à des évènements de fondation. Au Bénin, deux groupes éco-morphologiques ont été détectés suivant un gradient nord-sud, contrastant avec deux pools géniques présentant une distribution est-ouest.
P. butyracea est une espèce auto-compatible majoritairement allogame. La corrélation de paternité est plus élevée aux niveaux intra-fruit vs. inter-fruits, et au sein d’une population de petite taille vs. de grande taille. Les principaux pollinisateurs au Bénin sont deux oiseaux (Cyanomitra verticalis, Cinnyris coccinigastrus) et trois abeilles (Apis mellifera, Meliponula togoensis, Hypotrigona sp.). La productivité totale en fruits augmente en fonction de l’âge de l’arbre et varie en fonction de l’année, atteignant un pic pour les arbres ayant un diamètre de 60-80 cm. Les graines sont récalcitrantes et ont une teneur en eau de 42.5 ± 2.9 %.
L’analyse des paramètres de reproduction et de diversité génétique, associés aux facteurs écogéographiques, nous a permis de proposer un échantillon de neuf populations représentatives de la diversité à l’échelle du Bénin, dans la perspective d’une conservation in situ. Le succès de celle-ci dépendra des efforts conjugués des communautés locales, de la recherche forestière et de la définition d’un cadre législatif par le politique pour la protection des habitats. La conservation ex situ est envisagée sous forme d’un verger rassemblant diverses origines, présentant l’intérêt supplémentaire de permettre d’étudier les contributions de la diversité génétique et de la plasticité phénotypique à la variation phénotypique. / Pentadesma butyracea Sabine is one of the four species of the endemic genus Pentadesma in Africa. The species is distributed from Sierra Leone to Gabon in two major types of habitats: the discontinuous and dense Guineo-Congolian rainforests (Upper and Lower Guinea) and the Sudanian domain of the dry corridor of Dahomey (considered as a barrier to the exchange of genes and species between Upper and Lower Guinea). In the latter, the species is found in gallery forests and plays a vital role in the socio-economic livelihood of local communities due to the various resources and services that provide its products (food, medicine and traditional, etc.). However, pressure from many sources including the collection of seeds to make butter, habitat fragmentation and its destruction for market gardening, inadequate agricultural practices, fires, are serious threats to the species.
The aim of this work was to acquire appropriate knowledge for the conservation and sustainable management of genetic resources of the species. Three objectives were defined (i) study the phylogeography of the species; (ii) evaluate its morphological and genetic variability in Benin; and (iii) characterize its reproductive biology. In a preliminary work, eleven nuclear microsatellite markers of P. butyracea were developed (Chapter 2). They were used for the study of phylogeography and genetic diversity of P. butyracea (chapters 3 and 5), and to study the inbreeding depression and parameters of its breeding system (Chapter 7).
The characterization of the genetic lineages and their spatial distribution using intergenic regions from chloroplast DNA and ribosomal DNA (ITS) region detected two allopatric genetic lineages between Upper and Lower Guinea, indicating a high genetic differentiation and a phylogeographic signal. Microsatellite markers allowed us to detect three genepools matching with the three studied regions (Upper Guinea, Dahomey-Gap and Lower Guinea). Genetic diversity was low in the Dahomey Gap, moderate in Upper Guinea and high in Lower Guinea. These results indicate an ancient separation of populations from Central and West Africa, while those from Dahomey Gap could originate West African rainforests (Upper Guinea) during the African humid Holocene period. In this dry corridor, populations experienced high genetic drift, possibly due to founding events. In Benin, two eco-morphological groups were detected following a north-south gradient, contrasting with two gene pools presenting an east-west distribution.
Pentadesma butyracea is a self-compatible, mainly allogamous species. The correlation of paternity was higher within-fruit vs. among-fruits, and in population of small size vs. large size. The main pollinators in Benin are two birds (Cyanomitra verticalis, Cinnyris coccinigastrus) and three bees (Apis mellifera, Meliponula togoensis, Hypotrigona sp.). Total productivity in fruit increases with tree age and varies yearly, reaching a peak for trees of 60-80 cm of diameter class. Seeds are recalcitrant (i.e. they cannot be conserved at low temperature), having a water content of 42.5 ± 2.9% at maturity.
The analysis of reproduction and genetics parameters, associated with eco-geographic factors, enabled us to select nine populations representative of the diversity in Benin, from the perspective of in situ conservation. The success of the latter will depend on combined efforts of local communities, forest research and an adequate legislative framework for the protection of habitats. Ex situ conservation is envisaged as an orchard assembling various origins, and would have the additional advantage of allowing to study the contribution of genetic diversity and phenotypic plasticity to phenotypic variation.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Kempf, Florent. "Structure génétique et évolution de la spécialisation chez deux ectoparasites hématophages, les tiques Ixodes uriae et I. Ricinus, vecteurs de la borréliose de Lyme." Montpellier 2, 2008. http://www.theses.fr/2008MON20186.
Many studies have been devoted to understanding the origin of life's vast diversity. In parasitic organisms, host specialization may be a key process in the emergence and maintenance of this diversity. Host and parasite life history traits can shape the spatial and temporal patterns of genetic variation, and thus, the possibility of host-associated divergence. In this thesis, we examine the evolution of host specialization in two host/parasite systems involving tick vectors of Lyme borreliosis: Ixodes uriae, a tick that exploits colonial seabirds in polar regions and, Ixodes ricinus, a tick with a large spectrum of terrestrial hosts in Europe. These congeneric species share many traits, but differ noticeably by the characteristics of the hosts they exploit and the strategies they use to encounter these hosts. Based on the basic biology of these ticks, we have formulated several hypotheses concerning the distribution of their genetic variation in natural populations and particularly among their local hosts. Ticks were sampled across a large spatial scale and were characterized using microsatellite and mitochondrial markers. We analyzed this data using different statistical tools frequently employed in phylogeography and population genetics, including some recently developed methods. Taken as a whole, our results support a scenario of recent and recurrent evolution of host races in I. Uriae, where the local outcome of the interaction varies in space and among host species. Our results also suggest the existence of races specialized on different host types within I. Ricinus populations (birds, rodents, lizards, etc), and a potential mechanism for assortative mating in these races. Overall, the work presented in this thesis highlights the importance of parasitic traits for the diversification process (dispersal, host encounter strategies, mate pair formation). More specifically, the frequent evolution of specific host races within tick populations will have importance consequences for the circulation of the pathogens they carry and, as such, calls into question our current understanding of the epidemiology of tick-borne diseases such as Lyme borreliosis
Coudray, Clotilde. "Histoire génétique et évolution des populations berbérophones nord-africaines." Toulouse 3, 2006. http://www.theses.fr/2006TOU30185.
This research describes the genetic diversity of current North-African Berber communities according to three polymorphisms: the immunoglobulin allotypes (Gm system), some autosomic microsatellites and the mitochondrial DNA. Original data are presented for populations from Morocco and Egypt. Our multi-field study is based on biological, archaeological, historical, geographical and linguistic data in order to retrace the origins and the genetic history of Berber-speakers. For all markers, our results show that the Berbers are genetically closed to European populations but that they are differentiated from sub-Saharan groups. By the analysis of Siwan Berbers (from Egypt), a clear distinction is revealed between them and Berbers from the Maghreb. Then, we note that in North-West Africa, there isn’t a genetic differentiation between Berber- and Arabic-speakers
"Évaluation de la diversité génétique chez deux collections de soja à l'aide de marqueurs microsatellites." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25896/25896.pdf.
Lamarre, Philippe. "Variations dans la réponse de la diversité génétique de populations de couleuvres insulaires faisant face à la perte d’habitat." Thèse, 2015. http://hdl.handle.net/1866/12493.
La région métropolitaine de Montréal est formée de nombreuses îles à la jonction du fleuve Saint-Laurent et de la rivière des Outaouais, isolant ainsi les populations insulaires en fonction de distances respectives ainsi que des courants. Ce système offre un contexte idéal pour évaluer l’effet de la perte d’habitat liée à la pression d'urbanisation dans un paysage métropolitain insulaire ou en situation d’archipel. La présente étude a pour objectif de comparer l’effet de la perte d’habitat sur la diversité génétique de deux serpents très distincts, Storeria dekayi et Thamnophis sirtalis. Des analyses réalisées à l’aide de marqueurs microsatellites révèlent une plus importante structure génétique entre les populations de S. dekayi (FST=0,19) qu’entre celles de T. sirtalis (FST=0,07) dans la région montréalaise. Chez les deux espèces étudiées, la majorité des populations des habitats réduits présente une richesse allélique moyenne comparable à celle observée dans les habitats plus vastes. Néanmoins, certaines populations présentent des réponses différentes, dont des traces de goulots d’étranglement, une perte de richesse allélique ou encore une importante modification des fréquences alléliques. Au niveau régional, les résultats présentent une importante perte de diversité génétique chez les couleuvres se trouvant sur le continent alors que les populations insulaires de la région montréalaise constituent désormais un réservoir de diversité génétique. Les résultats observés auprès des populations insulaires démontrent que les effets de la perte d’habitat peuvent s’avérer très spécifiques à chaque situation et que la détection de traces génétiques d’un tel phénomène peut nécessiter un contexte logistique très particulier. Un nombre croissant de publications reportent une absence de signature génétique suite à la perte d’habitat chez des oiseaux et des mammifères. Il s’agit de la première étude témoignant de ce phénomène chez les reptiles. Une note est fournie en annexe à l’intention des gestionnaires au sujet de la conservation de la couleuvre brune, S. dekayi.
The Montreal metropolitan community includes numerous islands located at the confluence of the Saint-Lawrence and Ottawa Rivers. In such a fragmented landscape, dispersal of animals is limited by the distance between islands as well as the currents. This system offers an ideal context for the study of the effects of habitat loss on the genetic diversity of animal populations located on islands or archipelagos. This study seeks to assess the effects of habitat area by comparing the organization of genetic diversity of two highly distinct snake species, Storeria dekayi and Thamnophis sirtalis. Analysis realized with microsatellite markers reveals a much stronger genetic organisation in S. dekayi (FST=0.19) than in T. sirtalis (FST=0.07) in the Montreal area. For both studied species, most populations found in reduced habitats showed similar genetic diversity to what was observed in larger habitats. Nevertheless, some populations showed different responses to the loss of habitat, including traces of genetic bottlenecks, a loss in mean allelic richness or an important alteration of their allelic frequencies. This study also reveals an important loss of genetic diversity in the continental snake populations. At the regional scale, the results reveal an important loss of genetic diversity in the continental snake populations and that the insular populations of the Montreal area now constitute a reservoir of the remnant genetic diversity. Moreover, this study not only demonstrates that the genetic response to habitat loss can be very case-specific, but also that to detect traces of such a phenomenon can require a very particular framework. A growing number of publications based on birds and mammals have reported the absence of a genetic signature following a habitat loss. This is the first study to report this phenomenon in reptiles. A note intended for managers is provided about the conservation of the Dekay’s brown snake, S. dekayi.