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Les voies de signalisation utérines à l'émergence de la diapause embryonnaire chez le vison américainLefèvre, Pavine L.C. 08 1900 (has links)
La diapause embryonnaire se manifeste par un arrêt réversible du développement embryonnaire durant la période de préimplantation et induit un retard de l’implantation. Chez le vison américain, une diapause embryonnaire obligatoire caractérise chaque gestation. Si les mécanismes de contrôle de la diapause embryonnaire obligatoire chez cette espèce sont bien connus, le rôle utérin impliqué dans la réactivation de l’embryon demeure, quant à lui, encore inconnu.
Le sujet de ce doctorat a consisté dans un premier temps à explorer l’environnement utérin à la sortie de la diapause embryonnaire afin de caractériser, dans un deuxième temps, les principaux acteurs utérins qui provoquent la réactivation de l’embryon.
Nous avons effectué une analyse du transcriptome utérin à l’émergence de la diapause embryonnaire ce qui a permis de construire une librairie de 123 séquences d’ADNc utérines différentiellement exprimées à la réactivation de l’embryon et homologues à des séquences de gènes connues chez d’autres espèces. Ces gènes sont impliqués dans la régulation du métabolisme (25 %), de l’expression génique (21 %), de la transduction de signal (15 %), du cycle cellulaire (15 %), du transport (10 %) et de la structure cellulaire (9 %), reflétant ainsi d’importantes modifications utérines à la réactivation embryonnaire. Nous avons validé l’expression différentielle de dix gènes ainsi identifiés : GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxin like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), et trois gènes codant pour AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) et SAT1 (spermidine/spermine N1-acetyltransferase), des enzymes impliquées dans la biosynthèse des polyamines. Le patron de l’expression spatio-temporel de SPARC et d’HMGN1 illustrent spécifiquement un remodelage tissulaire et de la chromatine au niveau utérin à la sortie de la diapause embryonnaire.
Ayant mesuré une augmentation des concentrations utérines en polyamines à la reprise du développement embryonnaire, nous avons émis l’hypothèse que les polyamines seraient impliquées dans les événements menant à la sortie de la diapause. L’inhibition de la biosynthèse des polyamines par un traitement à l’ α-difluoromethylornithine (DFMO) a provoqué une diminution significative de la proliferation cellulaire dans les embryons à la réactivation, un retard du moment de l’implantation, mais n’a pas affecté le succès de la reproduction. De manière similaire, nous avons induit un état de dormance dans les cellules de trophoblaste de vison en présence DFMO dans le milieu de culture, et constaté que cet état était réversible.
En conclusion, cette étude a non seulement ouvert de nouveaux horizons quant à la compréhension du rôle utérin dans les événements menant à la sortie de la diapause embryonnaire, mais a démontré pour la première fois, l’existence de facteurs utérins indispensables à la réactivation de l’embryon: les polyamines. / Embryonic diapause is characterized by a reversible arrest of blastocyst development prior to implantation and delay in implantation. In the American mink, embryonic diapause is a characteristic of each gestation. Although the mechanisms which control obligate embryonic diapause of this species are well known, the role of the uterus involved in blastocyst reactivation remains elusive.
The subject of this doctoral research consisted first in exploring the uterine environment at the emergence of embryonic diapause in order to subsequently determine, the main factors in the uterus that provoke reactivation of the embryo.
We have undertaken an analysis of the uterine transcriptome at the emergence of embryonic diapause which has enabled us to set up a library of 123 cDNA uterine sequences differentially expressed at blastocyst reactivation, and homologue gene sequences known in other species. Twenty-five percent of these genes are implicated in genetic expression, 15 % in cell signal transduction, 15 % in cell cycle, 10 % in transport and 9 % in cell structure. All of them reflect significant uterine modifications at blastocyst reactivation. We have validated differential expression of ten genes, identified as: GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxine like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), and three genes encoding for AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) and SAT1 (spermidine/spermine N1-acetyltransferase), which are enzymes implicated in polyamine biosynthesis. The spatio-temporal expression patterns of SPARC and HMGN1 illustrate tissue and chromatin remodelling in the uterus at the termination of embryonic diapause.
Having measured an increase in concentration of polyamines in the uterus at the resumption of blastocyst development, we have hypothetized that polyamines are implicated in the emergence of blastocysts from diapause. We inhibited polyamine biosynthesis in pregnant mink females during early blastocyst reactivation. The inhibition of polyamine biosynthesis through treatment with α-difluoromehtylornithine (DFMO) provoked a major reduction in cell proliferation in blastocysts at reactivation and a delay in the timing of implantation, but did not affect the success of reproduction. Similarly, we induced a reversible dormant state in cultured mink trophoblast cells traited with DFMO.
To conclude, not only are results of this study a breakthrough in the understanding of the role of the uterus in stimulating at the emergence of blastocysts from embryonic diapause, but also, for the very first time, they indicate the existence of uterine factors, the polyamines, that are responsible for blastocysts reactivation.
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L'économie criminelle de la Camorra et la pratique discursive des différents points de vue dans Gomorra de Roberto SavianoMilia, Bruno 12 1900 (has links)
This thesis will study the Italian literary phenomenon Gomorra, viaggi nell'impero economico e nel sogno di dominio della Camorra. First, the focus will be on the text's hybrid nature and implications and also on its literary and intellectual inspirations (such as Truman Capote, Pier Paolo Pasolini and Leonardo Sciascia). Secondly, we will take a closer look at the structure of the novel's narrative and its literary details, in order to reveal the different processes used by Roberto Saviano to convince the reader. Interwoven in this book's central plot, we will find a main obsession: the need to understand.
Lastly, we will discuss the question of the great power treated in this novel, the one of a criminal organisation transformed by the revelations made throughout the story. These revelations will allow us to draw interesting comparisons between organized crime and merchant capitalism. For this part, we will refer to Guy Debord's La société du spectacle, and to Hannah Arendt's work on the question of totalitarianism. All of these elements will allow us to discuss the different perspectives within the narrative's framework, and more precisely, the figure of the narrator/author/character that gives Saviano's novel anthropological qualities, in the form of an ethnofiction (Augé). / Ce Mémoire cherchera a étudier le phénomène littéraire italien Gomorra, viaggio nell’impero economico e nel sogno di dominio della Camorra. Au fil de l’analyse il sera évoqué autant son caractère hybride et les implications que cela représente que les influences littéraires et intellectuelles, auquel un tel texte fait écho ( Truman Capote, Pier Paolo Pasolini, Leonardo Sciascia…). Par la suite nous nous attacherons aux structures narratives et aux particularités littéraires du roman, afin de faire ressortir les différents procédés utilisés par Roberto Saviano dans son intention de convaincre. Une obsession qui s’inscrit dans la dynamique centrale du livre, celle de comprendre.
Enfin, il sera question de la grande force qui entoure ce roman, celle d’un crime organisé rendu différent de par les révélations faites au sein du roman. De cela nous tirerons une étude comparative entre le crime organisé et le capitalisme marchand, faisant appel autant à Guy Debord et son œuvre La société du spectacle, qu’à Hannah Arendt pour ses nombreux travaux entourant la problématique du totalitarisme. Tous ces éléments nous permettront de conclure sur la particularité des points de vue, notamment avec la figure du narrateur/auteur/personnage qui nous permettra de rapprocher le roman de Roberto Saviano au travail anthropologique, dans la dynamique d’une forme d’ethno- fiction (Augé)
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IDENTIFICATION OF LOCI CONTRIBUTING TO THE SMITH-MAGENIS SYNDROME-LIKE PHENOTYPE AND MOLECULAR EVALUATION OF THE RETINOIC ACID INDUCED 1 GENEWilliams, Stephen 27 April 2010 (has links)
Smith-Magenis syndrome (SMS) is a multiple congenital abnormalities intellectual disability syndrome that results from a deletion of chromosome 17p11.2 or mutation of the retinoic acid inducted one gene (RAI1). SMS is characterized by a multitude of phenotypic features including craniofacial defects, short stature, obesity, intellectual disability, self-abusive behavior, sleep disturbance and behavioral abnormalities. Interestingly, although SMS is a clearly defined syndrome with a known molecular change at its foundation, ~40% of all candidate cases sent to the Elsea lab for evaluation do not have a mutation or deletion of RAI1. We hypothesize that at least one other locus must be responsible for this Smith-Magenis-like (SMS-like) phenotype. To address this hypothesis, we first compiled a cohort of 52 subjects who had been referred to the Elsea lab for a clinical diagnosis of SMS. Once these individuals were confirmed to not have an RAI1 mutation or deletion, their phenotypes were compiled and statically analyzed to distinguish whether SMS and SMS-like cohorts are different in the prevalence of the core phenotypes of SMS such as, but not limited to, sleep disturbance, self-abusive behavior and developmental delay. SMS-like and SMS cohorts are not different in prevalence for these core features. Next, all SMS-like subjects were sent for whole genome array comparative genomic hybridization (aCGH) to identify duplications or deletions of each individual’s genome which contribute to the phenotype observed. We identified 6 pathogenic copy number variants (CNVs) in six individuals which contribute directly to the clinical phenotype, including two del(2)(q37). This study enabled us to draw relationships between SMS and other syndromes that had never been appreciated before and helped to identify pathways in which RAI1 may function. Using the data from our SMS-like study we were able to further characterize two known syndromes; Deletion 2q37 syndrome (brachydactyly mental retardation syndrome) and deletion 2q23 syndrome. With regard to deletion 2q37, syndrome we used genomic data from known and new deletion 2q37 subjects to refine the critical region to one gene: the histone deacetylase 4 gene (HDAC4). Using both clinical and molecular clues, we were able to identify one subject from our SMS-like cohort who has an insertion in HDAC4 which results in a premature stop codon. We conclude from this study that mutation of HDAC4 results in brachydactyly mental retardation syndrome. With regard to deletion 2q23 syndrome there were only five known cases in the published literature to which we were able to add two more. Using as similar approach to our del2q37 study we refined the critical region for this syndrome to one gene, the methyl binding domain 5 gene (MBD5). Using a molecular and clinical approach we were able to conclude that haploinsufficiency of MBD5 results in the core phenotypes seen in del2q23 syndrome including microcephaly, intellectual disabilities, severe speech impairment, and seizures. Using all the data generated from the three previous studies we set out to characterize the molecular function of RAI1. We hypothesize that RAI1 is a transcription factor that regulates gene expression of core genes involved in development, neurological function, and circadian rhythm. Using a ChIP-chip based approach we identified 257 transcripts we believe RAI1 regulates. Following up on these transcripts, using in vitro and in vivo methods, we have been able to conclude that RAI1 is a positive regulator of CLOCK, the master regulator of the central circadian cycle. Taken together, these studies have given us insight into the specific molecular changes that contribute to SMS and SMS-like syndromes. We have unveiled pathways and genes which are important to normal human development and behavior and identified novel functions of RAI1. These studies will provide the foundation for the future discovery of the pathways affected.
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Variations développementales chez les poissons hybrides clonaux Chrosomus eos-neogaeus : transgressions phénotypiques en 3DDuclos, Kevin 08 1900 (has links)
Le succès écologique des organismes dépend principalement de leur phénotype. Une composante important du phénotype est la morphologie fonctionnelle car elle influence la performance d’un organisme donné dans un milieu donné et donc reflète son écologie. Des disparités dans la morphologie fonctionnelle ou dans le développement entre espèces peuvent donc mener à des différences écologiques.
Ce projet évalue le rôle des mécanismes de variation morphologique dans la production de différences écologiques entre espèces au sein des poissons hybrides du complexe Chrosomus eos-neogaeus. En utilisant la microtomodensitométrie à rayons X et la morphométrie géométrique 3D, la forme des éléments des mâchoires est décrite pour comparer la variation morphologique et les différences développementales entre les membres du complexe C. eos neogaeus.
Les hybrides présentent autant de variation phénotypique que les espèces parentales et présentent des phénotypes nouveaux, dit transgressifs. Les hybrides présentent aussi des différences marquées avec les espèces parentales dans leur allométrie et dans leur intégration phénotypique. Finalement, ceux-ci semblent être plastiques et en mesure de modifier leur phénotype pour occuper plusieurs environnements. L’entièreté de ces résultats suggère que des changements dans le développement des hybrides entraînent une différenciation phénotypique et écologique avec les espèces parentales. / An organism’s success is highly dependent on its phenotype. A major component of the phenotype is functional morphology because of its role in determining performance in a given environment clues as to their ecology. Morphological disparity and developmental differences between species can thus lead to ecological differences.
This project assesses the role that mechanisms capable of generating morphological variation have in producing ecological differences between species within the hybrid fishes of the Chrosomus eos-neogaeus complex. Using X-ray based computer-aided micro-tomography and 3D geometric morphometrics, the shape of bones composing the jaws was described to measure morphological variation and developmental differences in the C. eos-neogaeus complex.
Chrosomus eos-neogaeus hybrids displayed as much variation as parental species and novel, deemed transgressive, phenotypes. Hybrids were also markedly different from parental species in their patterns of allometric scaling and phenotypic integration. Finally, hybrids appeared to be plastic and able to acclimate to different environments. The results of this study indicate that changes in the development of hybrids could lead to phenotypic and, in turn, ecological differences with parental species.
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Recherche translationnelle sur les dystrophies myotoniques : étude de biomarqueurs et mise en place d’un observatoire national pour les essais cliniquesBassez, Guillaume 15 December 2011 (has links)
Pas de résumé français / Pas de résumé anglais
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Hybridation et dynamique de la spéciation chez les chênes sessile (Quercus petraea) et pédonculé (Quercus robur) / Hybridization and speciation dynamic of Quercus petraea and Quercus roburLagache, Lélia 14 December 2012 (has links)
Les chênes sessiles et pédonculés sont deux espèces sympatriques interfertiles occupant des places distinctes dans la succession écologique. Elles constituent pour cela un bon modèle pour l’étude de la spéciation écologique. Malgré leur écologie contrastée, les deux espèces de chênes coexistent naturellement dans de nombreuses forêts, rendant possible l’étude de leur système de reproduction intra- et interspécifique. Des travaux précédents ont suggéré que l’hybridation entre ces deux espèces serait fréquence-dépendante. Elle dépendrait de la proportion de pollen allospécifique (c'est-à-dire de pollen de l’autre espèce) que reçoit l’arbre mère étudié. Ce phénomène d’hybridation fréquence-dépendante est appelé effet Hubbs, du nom d’un ichtyologue qui découvrit ce mécanisme en 1955. Mon travail a consisté à étudier, dans une parcelle mixte de chênes, les barrières à l’hybridation qui permettent la coexistence de ces deux espèces. Pour cela, j’ai effectué une étude de paternité de grande ampleur (près de 3500 individus typés sur 12 marqueurs microsatellites). Tout d’abord, je me suis intéressée à la délimitation des deux espèces en appliquant pour la première fois in situ le critère d’interfertilité. Je me suis ensuite concentrée sur les facteurs qui influencent l’hybridation au travers d’une modélisation des croisements à l’échelle de l’individu. Les résultats montrent que le maintien de ces deux espèces est régi par deux composantes environnementales importantes : la fréquence de chaque espèce et leur distribution, qui influencent la quantité de pollen reçue. Grâce à cette étude empirique et à l’approche de modélisation de ces croisements, nous avons désormais une bien meilleure vision de l’effet de l’environnement sur l’hybridation. J’ai par la suite comparé les caractéristiques du système de reproduction de chaque espèce (dispersion du pollen et fécondité mâle) en cherchant si un lien existait avec leur stratégie écologique. Les résultats suggèrent que les différences de dynamique écologique pourraient être à l’origine de la spéciation du fait de l’existence de compromis différents en termes d’allocation de ressources mais qu’à plus court terme la stabilité de l’environnement est essentielle au maintien des espèces. / Quercus petraea and Q. robur are two interfertile sympatric species. They occupy distinct stages during forest succession and constitute therefore good models for ecological speciation studies. Despite their differences, they often grow together in mixed stands, allowing the study of their intra- and interspecific reproductive system. Hybridization between these two oak species has been suggested to be frequency-dependent. The effect of the relative species abundance on hybridization is known as the “Hubbs’ effect”, from the name of an ichthyologist who described this mechanism in 1955. My work was to study the processes that limit hybridization between these two species, thereby allowing their coexistence. I conducted an extensive paternity analysis (almost 3500 individuals genotyped at 12 microsatellite markers). First, I tried to delimitate the two oak species by applying for the first time in situ the interfertility criterion. Then, I focused on interspecific crosses by studying those factors influencing hybridization. Results showed that the maintenance of these two species depends on the frequency of each species and their distribution, as both factors influence the quantity of pollen received by female flowers. Thanks to this empirical study and to this modeling approach, we have now a much better view of environmental effects on hybridization. I then compared the characteristics of the reproductive system of each species (pollen dispersal and male fertility) in relation with their ecological strategies. The results suggest that differences in species ecological dynamics are at the origin of the speciation process but that at a finer scale the stability of the environment is crucial for species’ maintenance.
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Hybridizace mezi Pulsatilla pratensis a P. patens ? Skutečnost nebo mýtus? / Interspecific hybridization between Pulsatilla pratensis and P. patensKrejčová, Nikol January 2014 (has links)
This thesis deals with interspecific hybridization in sympatric populations of Pulsatilla patens and P. pratensis. The key aim was to assess karyological and phenotypic variation in the study group. DNA flow cytometry revealed three non-overlapping groups of genome sizes, corresponding to P. patens, P. × hackelii and P. pratensis. The frequency of interspecific hybridization was low, accounting to approx. 3% of analyzed plants. Morphometric analyses identified a set a reliable species-specific characters, including number of divisions the leaf, length of petiole the part of leaf, number of smaller parts of leaf and colour of blossom. Although the majority of hybrid individuals flowered and set fruits, their fertility was reduced considerably. The threat from interspecific hybridization to parental species is therefore rather low.
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Reprodukční izolace diploidů a tetraploidů druhu Vicia cracca a možnosti evoluce tohoto agregátu / Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregateVlčková, Zuzana January 2014 (has links)
Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prereproducitve barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of species of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproctive barriers is 0,956. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants. I prepared one squash of diploid V. cracca using method of in situ hybridization. This method needs to be optimilized for studied taxon.
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Evoluční vztahy tetraploidních zástupců skupiny Galium pusillum (sekce Leptogalium) na území střední Evropy. Alopatrická diferenciace českého endemického druhu G. sudeticum. / Evolutionary history of tetraploid representatives Galium pusillum group (sect. Leptogalium) in central Europe. Allopatric differentiation of Czech endemic species G. sudeticumKnotek, Adam January 2014 (has links)
The presented study tries to reveal the evolutionary history of polyploid complex Galium pusillum aiming on a rare czech endemic species G. sudeticum, an ideal model to study allopatric speciation in the context of Central European (post)glacial development. The species G. sudeticum grows in Krkonose Mts. and on serpentines in western Bohemia (Slavkovský les) more than 200 kilometers away. Our morphological and molecular data suggest a clearly different history of its two isolated areas. The populations in Krkonose Mts. are probable relics of mountainous species G. anisophyllon which was there on its northern border of occurence and hybridized with lowland species G. valdepilosum during postglacial vegetations shifts. This fact is well supported by intermediate position of Krkonose Mts. populations in both morphological and molecular AFLP analyses and by sharing the same chloroplast haplotype with geographically close lowland populations. On the other hand the serpentine lowland populations in western Bohemia are both morphologicaly and genetically indistinguishable from G. valdepilosum. Distinct genetic lineage of few populations belonging to G. valdepilosum (incl. one traditionaly referred as G. sudeticum) was found in western Bohemia and Bavaria, located on relic stands (calcareous and serpentine...
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Reprodukční izolace diploidů a tetraploidů druhu Vicia cracca a možnosti evoluce tohoto agregátu / Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregateVlčková, Zuzana January 2016 (has links)
Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prezygotic barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of spieces of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is, I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproductive barriers is 0,990. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants.
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