Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The cyp19a1 gene that encodes aromatase, the only enzyme permitting conversion of C19 aromatizable androgens into estrogens, is present as a single copy in the genome of most vertebrate species, except in teleosts in which it has been duplicated. This study aimed at investigating the brain expression of a cyp19a1 gene expressed in both gonad and brain of Japanese eel, a basal teleost. By means of immunohistochemistry and in situ hybridization, we show that cyp19a1 is expressed only in radial glial cells of the brain and in pituitary cells. Treatments with salmon pituitary homogenates (female) or human chorionic gonadotrophin (male), known to turn on steroid production in immature eels, strongly stimulated cyp19a1 messenger and protein expression in radial glial cells and pituitary cells. Using double staining studies, we also showed that aromatase-expressing radial glial cells exhibit proliferative activity in both the brain and the pituitary. Altogether, these data indicate that brain and pituitary expression of Japanese eel cyp19a1 exhibits characteristics similar to those reported for the brain specific cyp19a1b gene in teleosts having duplicated cyp19a1 genes. This supports the hypothesis that, despite the fact that eels also underwent the teleost specific genome duplication, they have a single cyp19a1 expressed in both brain and gonad. Such data also suggest that the intriguing features of brain aromatase expression in teleost fishes were not gained after the whole genome duplication and may reflect properties of the cyp19a1 gene of ancestral Actinopterygians.
ISSN: 1932-6203

hal-00877375
https://hal.archives-ouvertes.fr/hal-00877375
https://hal.archives-ouvertes.fr/hal-00877375/document
https://hal.archives-ouvertes.fr/hal-00877375/file/Expressionsur Aromatase-accepted.pdf
DOI : 10.1371/journal.pone.0044750

Éditeur(s) : HAL CCSD Society for Molecular Biology and Evolution
Résumé : International audience
Complex nongradual evolutionary processes such as gene remodeling are difficult to model, to visualize, and to investigate systematically. Despite these challenges, the creation of composite (or mosaic) genes by combination of genetic segments from unrelated gene families was established as an important adaptive phenomena in eukaryotic genomes. In contrast, almost no general studies have been conducted to quantify composite genes in viruses. Although viral genome mosaicism has been well-described, the extent of gene mosaicism and its rules of emergence remain largely unexplored. Applying methods from graph theory to inclusive similarity networks, and using data from more than 3,000 complete viral genomes, we provide the first demonstration that composite genes in viruses are 1) functionally biased, 2) involved in key aspects of the arm race between cells and viruses, and 3) can be classified into two distinct types of composite genes in all viral classes. Beyond the quantification of the widespread recombination of genes among different viruses of the same class, we also report a striking sharing of genetic information between viruses of different classes and with different nucleic acid types. This latter discovery provides novel evidence for the existence of a large and complex mobilome network, which appears partly bound by the sharing of genetic information and by the formation of composite genes between mobile entities with different genetic material. Considering that there are around 10E31 viruses on the planet, gene remodeling appears as a hugely significant way of generating and moving novel sequences between different kinds of organisms on Earth.
ISSN: 1759-6653

Droits : http://creativecommons.org/licenses/by/
hal-01324848
http://hal.upmc.fr/hal-01324848
http://hal.upmc.fr/hal-01324848/document
http://hal.upmc.fr/hal-01324848/file/Genome%20Biol%20Evol-2014-Jachiet-2195-205.pdf
DOI : 10.1093/gbe/evu168

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
BACKGROUND: Mammalian spermatogenesis is a process that involves a complex expression program in both somatic and germ cells present in the male gonad. A number of studies have attempted to define the transcriptome of male meiosis and gametogenesis in rodents and primates. Few human transcripts, however, have been associated with testicular somatic cells and germ cells at different post-natal developmental stages and little is known about their level of germline-specificity compared with non-testicular tissues. METHODS: We quantified human transcripts using GeneChips and a total of 47 biopsies from prepubertal children diagnosed with undescended testis, infertile adult patients whose spermatogenesis is arrested at consecutive stages and fertile control individuals. These results were integrated with data from enriched normal germ cells, non-testicular expression data, phenotype information, predicted regulatory DNA-binding motifs and interactome data. RESULTS: Among 3580 genes for which we found differential transcript concentrations in somatic and germ cells present in human testis, 933 were undetectable in 45 embryonic and adult non-testicular tissues, including many that were corroborated at protein level by published gene annotation data and histological high-throughput protein immunodetection assays. Using motif enrichment analyses, we identified regulatory promoter elements likely involved in germline development. Finally, we constructed a regulatory disease network for human fertility by integrating expression signals, interactome information, phenotypes and functional annotation data. CONCLUSIONS: Our results provide broad insight into the post-natal human testicular transcriptome at the level of cell populations and in a global somatic tissular context. Furthermore, they yield clues for genetic causes of male infertility and will facilitate the identification of novel cancer/testis genes as targets for cancer immunotherapies.
ISSN: 0268-1161

hal-00877243
https://hal.archives-ouvertes.fr/hal-00877243
DOI : 10.1093/humrep/des301
PUBMED : 22926843

Éditeur(s) : CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines
Extrait de : "Patrimonialisation et développement dans la Caraïbe et les Amériques" : colloque international, du 2 au 4 mars 2011. Université des Antilles et de la Guyane
Description : Parmi les processus de patrimonialisation, l'intelligibilité et la connaissance du passé révèle des formes par lesquelles une nation et un état se projette dans l'avenir. Ce fût ainsi le cas pour le site de Teotihuacán au Mexique où à l'aide d'une archéologie systématique, des politiques ont conforté l'identité mexicaine en la réconciliant avec sa genèse. En effet, des courants intellectuels pensent déterminer et améliorer les relations entre territoires et populations par l'anthropologie, la géographie et la biologie.
Siècle(s) traité(s) : 20
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V12040
V12040

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Introduction Le paysage est le produit de l’interaction entre un ordre de la nature et un ordre spatio-social qui expliquent ensemble sa genèse, son évolution, sa permanence ou ses mutations. En conséquence de sa nature même, le paysage « bouge ». Il mue au rythme des jours et des saisons qui modifient les conditions de lumière et la végétation. Le paysage se transforme également au cours des siècles en suivant les mutations économiques et sociales. Aux Antilles, des recherches de plus en plu...
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.763
http://journals.openedition.org/etudescaribeennes/763

Éditeur(s) : Public Library Science
Résumé : Background: Reconstructing the history of divergence and gene flow between closely-related organisms has long been a difficult task of evolutionary genetics. Recently, new approaches based on the coalescence theory have been developed to test the existence of gene flow during the process of divergence. The deep sea is a motivating place to apply these new approaches. Differentiation by adaptation can be driven by the heterogeneity of the hydrothermal environment while populations should not have been strongly perturbed by climatic oscillations, the main cause of geographic isolation at the surface. Methodology/Principal Finding: Samples of DNA sequences were obtained for seven nuclear loci and a mitochondrial locus in order to conduct a multi-locus analysis of divergence and gene flow between two closely related and hybridizing species of hydrothermal vent mussels, Bathymodiolus azoricus and B. puteoserpentis. The analysis revealed that (i) the two species have started to diverge approximately 0.760 million years ago, (ii) the B. azoricus population size was 2 to 5 time greater than the B. puteoserpentis and the ancestral population and (iii) gene flow between the two species occurred over the complete species range and was mainly asymmetric, at least for the chromosomal regions studied. Conclusions/Significance: A long history of gene flow has been detected between the two Bathymodiolus species. However, it proved very difficult to conclusively distinguish secondary introgression from ongoing parapatric differentiation. As powerful as coalescence approaches could be, we are left by the fact that natural populations often deviates from standard assumptions of the underlying model. A more direct observation of the history of recombination at one of the seven loci studied suggests an initial period of allopatric differentiation during which recombination was blocked between lineages. Even in the deep sea, geographic isolation may well be a crucial promoter of speciation.
Plos One (1932-6203) (Public Library Science), 2009-08 , Vol. 4 , N. 8 , P. 1-15

Droits : 2009 Faure et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
http://archimer.ifremer.fr/doc/00129/24012/21972.pdf
DOI:10.1371/journal.pone.0006485
http://archimer.ifremer.fr/doc/00129/24012/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Two genome-wide association studies (GWASs) recently highlighted the HLA-DRA and HLA-DRB5 genes as associated with Parkinson disease (PD). However, because HLA-DRA displays a low level of polymorphisms and HLA-DRB5 is only present in approximately 20% of the population, these findings are difficult to interpret. Our aims were: (1) to replicate and investigate in greater detail the association between PD and the HLA-DR region; (2) to identify PD-associated HLA alleles; and (3) to perform a meta-analysis of our top finding. As part of 2 French population-based case-control studies of PD including highly ethnically homogeneous participants, we investigated the association between PD and 51 Single-nucleotide polymorphisms (SNPs) in the HLA-DR region. HLA-DRB1 alleles were imputed using the HLA(*) IMP software. HLA typing was performed in a subsample of the participants. We performed a meta-analysis of our top finding based on 4 GWAS data sets. Among 499 cases and 1123 controls, after correction for multiple testing, we found an association with rs660895 (OR/minor allele, 0.70; 95% CI, 0.57-0.87) within the HLA-DRB1 gene, which encodes the most polymorphic HLA-DR chain (DRβ). A meta-analysis (7996 cases, 36455 controls) confirmed this association (OR, 0.86; 95% CI, 0.82-0.91; P < .0001). SNP-based imputation of HLA alleles showed an inverse association between PD and the HLA-DRB1(*) 04 allele. We replicated an association between PD and the HLA-DR region and provided further insight into the loci and alleles involved. The highly polymorphic HLA-DRB1 locus contains rs660895, which represents a more legitimate candidate than previous ones. Our finding is in agreement with the hypothesis of an immune component in PD pathophysiology. © 2012 Movement Disorder Society.
ISSN: 0885-3185

inserm-00721562
http://www.hal.inserm.fr/inserm-00721562
http://www.hal.inserm.fr/inserm-00721562/document
http://www.hal.inserm.fr/inserm-00721562/file/Table1.pdf
http://www.hal.inserm.fr/inserm-00721562/file/Table2.pdf

Éditeur(s) : Université des Antilles
Extrait de : "Hommage au Professeur Léo Elisabeth" : conférence, le 25 mai 2018. Université des Antilles
Description : Vincent Cousseau, maître de conférences à l'Université de Limoges, explique que la Martinique du long XVIIIe siècle a été le champ d'étude de prédilection de Léo Elisabeth. Son vif intérêt pour l'île l'a incité à mobiliser l'histoire sociale et démographique pour la réalisation de sa thèse, en prenant soin de les adapter aux spécificités des sources antillaises. Il a ainsi tracé la genèse et les contours des Libres de couleur martiniquais, groupe intermédiaire discriminé, mais en pleine ascension lorsque la Révolution franchit l'Atlantique. À la lumière des nouvelles études qui font écho à ses travaux et de sources récemment exhumées, Vincent Cousseau réexamine le rôle des Libres de couleur de la Martinique dans la Révolution. Loin d'être univoque, leur engagement a connu une remarquable diversité, passant de l'engagement auprès des planteurs à la mobilisation pour la République, parfois jusqu'au sacrifice.

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V18174
V18174

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
BACKGROUND: Cancer/Testis (CT) genes are expressed in male gonads, repressed in most healthy somatic tissues and de-repressed in various somatic malignancies including prostate cancers (PCa). Because of their specific expression signature and their associations with tumor aggressiveness and poor outcomes, CT genes are considered to be useful biomarkers and they are also targets for the development of new anti-cancer immunotherapies. The aim of this study was to identify novel CT genes associated with hormone-sensitive prostate cancer (HSPC), and castration-resistant prostate cancer (CRPC). METHODS: To identify novel CT genes we screened genes for which transcripts were detected by RNA profiling specifically in normal testis and in either HSPC or CRPC as compared to normal prostate and 44 other healthy tissues using GeneChips. The expression and clinicopathological significance of a promising candidate-NR6A1-was examined in HSPC, CRPC, and metastatic site samples using tissue microarrays. RESULTS: We report the identification of 98 genes detected in CRPC, HSPC and testicular samples but not in the normal controls. Among them, cellular levels of NR6A1 were found to be higher in HSPC compared to normal prostate and further increased in metastatic lesions and CRPC. Furthermore, increased NR6A1 immunoreactivity was significantly associated with a high Gleason score, advanced pT stage and cancer cell proliferation. CONCLUSIONS: Our results show that cellular levels of NR6A1 are correlated with disease progression in PCa. We suggest that this essential orphan nuclear receptor is a potential therapeutic target as well as a biomarker of PCa aggressiveness. Prostate © 2013 Wiley Periodicals, Inc.
ISSN: 0270-4137

inserm-00821963
http://www.hal.inserm.fr/inserm-00821963
DOI : 10.1002/pros.22659
PUBMED : 23532770

Éditeur(s) : HAL CCSD
Résumé : Ctenophores are one of the four animal phyla positioned outside from the Bilateria. Most ctenophore species are planktonic and gelatinous, and are easily recognisable by their eight comb rows used for swimming. Ctenophore systematics remains nowadays poorly understood. Anatomical characters do not help much in placing them within the animal tree, and similarly the grounds for establishment of their internal phylogeny as well as delimitation of species are notoriously weak due to a paucity of informative morpho-anatomical characters. Until now, the use of molecular data has failed to improve significantly this situation. The aim of this PhD thesis was to bring a contribution to our understanding of ctenophore evolution at different taxonomic scales. At the metazoan level, the position of ctenophores was addressed using a phylogenomic approach. Taxonomic sampling was significantly improved through sequencing and assembly of transcriptomes of 22 non-bilaterian species (belonging to ctenophores, cnidarians and sponges). Two independent datasets were analysed, one consisting in an update of an existing supermatrix of 128 genes, the other one (4235 genes) having been entirely built de novo, thanks to a newly-devised semi-automated protocol intended to eliminate all major potential causes of artefacts (contaminations, paralogies, missing data). Results clearly contradict recent phylogenomic studies which claimed Ctenophora to be the most early-diverging animal lineage, our analyses instead supporting Porifera as the sister-group to other metazoans. The exact position of ctenophores remains however uncertain at this stage, different conditions of analyses yielding three contradictory hypotheses as open possibilities. At the intra-phyletic level, analyses of a ADNr 18S and ITS (internal transcribed spacers) dataset, together with study of duplicated genes and the results of phylogenomic analyses, allowed resolving most phylogenetic relationships between ctenophore orders and families, including the placement of the ctenophore tree root. Finally, at smaller taxonomic scale, in-depth comparison between two species of the genus Pleurobrachia using immunohistochemistry demonstrates the potential of these techniques for uncovering new structural “micro-anatomical” characters useful for diagnosis and identification of ctenophore species. It is our hope that this work will contribute to improving the systematics of a poorly known phylum of great importance for understanding early animal evolution.
Les cténophores représentent l’un des quatre embranchements animaux extérieurs aux Bilateria. La majoritédes espèces sont planctoniques et gélatineuses, et sont reconnaissables à leurs huit rangées de peignes dont lebattement permet la nage. Leur systématique est encore de nos jours mal comprise. L'anatomie descténophores offre peu de caractères aussi bien pour placer la lignée dans l’arbre des métazoaires, que pourétablir les relations de parenté au sein de l’embranchement et délimiter les espèces, et jusqu’à présent lesdonnées moléculaires n’ont pas permis de résoudre ces problèmes de manière satisfaisante. L’objectif de cetravail de thèse est de contribuer à améliorer notre compréhension de l'évolution des cténophores àdifférentes échelles taxonomiques. A l’échelle des métazoaires, la position phylogénétique des cténophores aété abordée par une approche phylogénomique. Un effort significatif a été réalisé pour améliorerl’échantillonnage taxonomique à travers le séquençage et l’assemblage des transcriptomes de 22 espèces denon-Bilateria (cténophores, cnidaires, spongiaires). Deux jeux de données indépendants ont été analysés, lepremier représentant une mise à jour d’une supermatrice existante de 128 gènes ; le second (4235 gènes)ayant été entièrement construit de novo via un protocole original comportant la mise au point de nouvellesméthodes pour traiter de manière semi-automatisée les principales sources potentielles d’artéfact(contaminations, paralogies, données manquantes). Les résultats contredisent certaines études récentes enmontrant que les spongiaires et non les cténophores représentent le groupe-frère des autres métazoaires. Laposition exacte de ces derniers reste à ce stade incertaine (trois options se présentant suivant les analyses). Al’échelle intra-phylétique, l'analyse d'un jeu de données comprenant les marqueurs ADNr 18S et InternalTranscribed Spacers (ITS), associée à des analyses de gènes dupliqués chez les cténophores et aux analysesphylogénomiques précédentes, a permis de résoudre une grande partie des relations phylogénétiques entre lesordres et les familles de cténophores, tout en permettant de préciser la position de la racine. Enfin, à uneéchelle taxonomique plus fine, une comparaison approfondie entre deux espèces du genre Pleurobrachia aumoyen de marquages immunohistochimiques montre le potentiel de ces techniques comme source denouveaux caractères structuraux « micro-anatomiques » à valeur diagnostique pour la délimitation etl’identification des espèces de cténophores. En conclusion, ce travail se veut une contribution au progrès dela systématique d’un embranchement encore méconnu et d’une grande importance pour la compréhensiondes évènements anciens de l’évolution animale.
https://tel.archives-ouvertes.fr/tel-01165014

NNT : 2014PA066448
tel-01165014
https://tel.archives-ouvertes.fr/tel-01165014
https://tel.archives-ouvertes.fr/tel-01165014/document
https://tel.archives-ouvertes.fr/tel-01165014/file/these_archivage_3158995o.pdf

Éditeur(s) : Archives nationales d'outre-mer
87MIOM35/1
Antilles
Saint-Domingue

Droits : Reproduction soumise à autorisation des Archives nationales d'outre-mer
http://www.patrimoines-martinique.org/ark:/35569/a011426186902aXxLR9

Éditeur(s) : HAL CCSD
Résumé : il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : ACTIVITY_REPORT
Understanding genomic evolution in wild populations is of particular importance because evolution is a central process in our understanding of populations’ history and their future response to global changes. In addition to fundamental knowledge, the study of populations’ evolution has wide applications such as conservation/restoration genetics or epidemiology. Indeed, genetic diversity is the ‘fuel’ for populations’ evolution and adaptation to new conditions, and estimating the extent and the geographic structure of genetic diversity, as well as identifying the evolutionary forces behind (demography, gene flow, and adaptation) are thus major challenges in the current context of global changes. [br/]A particular attention is currently devoted to the process of genetic divergence in wild populations, with emphases on gene flow, local adaptation, and their interactions. Indeed, adaptation in wild populations is supported in many species by many kinds of experiments based on both quantitative phenotypic traits and molecular data. However, the processes governing populations’ evolution are poorly understood in the tropical rainforest of Amazonia, and the relative influence of neutral and adaptive processes are continuously discussed. [br/]I am a young scientist interested in the process of genomic divergence in wild (tree) populations. I aimed at understanding how evolution structures the genetic diversity and governs molecular divergence in wild populations, with particular emphases on gene flow and local adaptation. During five years as a young scientist, I worked on answering the following questions, focusing on two tree species occupying vulnerable areas: mainly [i]Eperua falcata[/i] in Amazonia and, to a lesser extent, [i]Abies alba[/i] in the Mediterranean area.[br/][u]Scientific questions:[/u][br/]- Which evolutionary drivers are responsible of the structure of genetic diversity in wild populations occupying wide areas? This question was addressed at different geographical scales: from large (regional) to very local (microgeographic) scales. [br/]- What is the relative influence of neutral (gene flow, inbreeding) and adaptive drivers in the process of genetic divergence?[br/]- Is microgeographic adaptation possible in spite of extensive gene flow between populations occupying the extreme boundaries of an ecological gradient? [br/]- What is the extent of natural selection in the (whole) genome of wild populations? [br/][br/]My research work is at the interface between three promising disciplines: Evolutionary genomics (i.e. the study of populations evolution and the evolutionary drivers behind), Bioinformatics (i.e. the treatment of next-generation data), and Bayesian modelling (i.e. the empirical calibration of complex mechanistic model). I intend to take advantage of the recent advances in sequencing and informatic technologies to bring up to date the field of ecological genetics and evolutionary biology, by developing modern research strategies to study the process of genomic divergence in wild populations.
https://hal.archives-ouvertes.fr/hal-01204218

hal-01204218
https://hal.archives-ouvertes.fr/hal-01204218
PRODINRA : 286326

Éditeur(s) : Wiley / Blackwell
Résumé : P>The distribution of the archaeal communities in deep subseafloor sediments [0-36 m below the seafloor (mbsf)] from the New Caledonia and Fairway Basins was investigated using DNA- and RNA-derived 16S rRNA clone libraries, functional genes and denaturing gradient gel electrophoresis (DGGE). A new method, Co-Migration DGGE (CM-DGGE), was developed to access selectively the active archaeal diversity. Prokaryotic cell abundances at the open-ocean sites were on average similar to 3.5 times lower than at a site under terrestrial influence. The sediment surface archaeal community (0-1.5 mbsf) was characterized by active Marine Group 1 (MG-1) Archaea that co-occurred with ammonia monooxygenase gene (amoA) sequences affiliated to a group of uncultured sedimentary Crenarchaeota. However, the anoxic subsurface methane-poor sediments (below 1.5 mbsf) were dominated by less active archaeal communities, such as the Thermoplasmatales, Marine Benthic Group D and other lineages probably involved in the methane cycle (Methanosarcinales, ANME-2 and DSAG/MBG-B). Moreover, the archaeal diversity of some sediment layers was restricted to only one lineage (Uncultured Euryarchaeota, DHVE6, MBG-B, MG-1 and SAGMEG). Sequences forming two clusters within the Thermococcales order were also present in these cold subseafloor sediments, suggesting that these uncultured putative thermophilic archaeal communities might have originated from a different environment. This study shows a transition between surface and subsurface sediment archaeal communities.
Environmental Microbiology (1462-2912) (Wiley / Blackwell), 2009-09 , Vol. 11 , N. 9 , P. 2446-2462

Droits : 2009 Society for Applied Microbiology and Wiley - Blackwell Publishing Ltd.
http://archimer.ifremer.fr/doc/2009/publication-6801.pdf
DOI:10.1111/j.1462-2920.2009.01976.x
http://archimer.ifremer.fr/doc/00000/6801/

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : International audience
BACKGROUND: Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (ADPD), the most common of which is the p.G2019S substitution that has been found at varying frequencies worldwide. Because of the size of the LRRK2 gene, few studies have analysed the entire gene in large series of ADPD families. METHODS: We performed extensive mutation analyses of all 51 coding exons of the LRRK2 gene in index cases from 226 Parkinson's disease families compatible with autosomal dominant inheritance, mostly from France (n = 182) and North Africa (n = 14). RESULTS: We found 79 sequence variants, 29 of which were novel. Eight potentially or proven pathogenic mutations were found in 22 probands (9.7%). There were four novel amino acid substitutions that are potentially pathogenic (p.S52F, p.N363S, p.I810V, p.R1325Q) and two novel variants, p.H1216R and p.T1410M, that are probably not causative. The common p.G2019S mutation was identified in 13 probands (5.8%) including six from North Africa (43%). The known heterozygous p.R1441H and p.I1371V mutations were found in two probands each, and the p.E334K variant was identified in one single patient. Most potentially or proven pathogenic mutations were located in the functional domains of the Lrrk2 protein. CONCLUSION: This study leads us to conclude that LRRK2 mutations are a common cause of autosomal dominant Parkinson's disease in Europe and North Africa.
ISSN: 0022-2593

inserm-00529272
http://www.hal.inserm.fr/inserm-00529272
DOI : 10.1136/jmg.2008.062612
PUBMED : 19357115

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
In contrast to mammals that have limited proliferation and neurogenesis capacities, the Xenopus frog exhibit a great potential regarding proliferation and production of new cells in the adult brain. This ability makes Xenopus a useful model for understanding the molecular programs required for adult neurogenesis. Transcriptional factors that control adult neurogenesis in vertebrate species undergoing widespread neurogenesis are unknown. NeuroD1 is a member of the family of proneural genes, which function during embryonic neurogenesis as a potent neuronal differentiation factor. Here, we study in detail the expression of NeuroD1 gene in the juvenile and adult Xenopus brains by in situ hybridization combined with immunodetections for proliferation markers (PCNA, BrdU) or in situ hybridizations for cell type markers (Vimentin, Sox2). We found NeuroD1 gene activity in many brain regions, including olfactory bulbs, pallial regions of cerebral hemispheres, preoptic area, habenula, hypothalamus, cerebellum and medulla oblongata. We also demonstrated by double staining NeuroD1/BrdU experiments, after long post-BrdU administration survival times, that NeuroD1 gene activity was turned on in new born neurons during post-metamorphic neurogenesis. Importantly, we provided evidence that NeuroD1-expressing cells at this brain developmental stage were post-mitotic (PCNA-) cells and not radial glial (Vimentin+) or progenitors (Sox2+) cells.
ISSN: 1932-6203

hal-00877023
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023/file/The_Neurogenic_Factor-accepted.pdf
DOI : 10.1371/journal.pone.0066487

Résumé : Aux Antilles, la faible fréquence des coronaropathies pourrait être liée à des facteurs génétiques, ethniques et/ou une distribution spécifique des facteurs de risque cardio-vasculaire (FDRCV). Les propriétés l'ANP (Atrial Natriuretic Peptide) et l'influence de certains polymorphismes de son gène, fréquents dans les populations d'ascendance Africaine pourraient également être en cause. L'analyse des dossiers de 638 patients coronariens consécutifs a mis en évidence une forte prévalence de l'hypertension artérielle et du diabète dans cette population et révélé des différences significatives dans la prévalence des FDRCV entre Afro-Caribéens (AC), Caucasiens et descendants de migrants Indiens. L'analyse angiographique de 420 patients AC a révélé que le diabète était le FDRCV le plus fortement lié à la sévérité des lésions coronaires alors l'obésité apparaissait comme un facteur protecteur. La transfection in vitro, de cellules musculaires lisses artérielles par une construction adénovirale porteuse du gène de l'ANP a entrainé une inhibition de la prolifération et de la migration cellulaire de 31 % et 25% respectivement. In vivo, cet effet s'est traduit par une réduction de 25% de la formation néotimale et de 28% du rapport intima/média dans un modèle d'hyperplasie de carotide de rat. Dans étude transversale incluant 210 sujets diabétiques AC nous avons mis en évidence une association entre le polymorphisme rs5065 (22381>C) du gène de l'ANP et l'existence d'une coronaropatbie. Dans cette étude, l'odds ratio de la présence d'une coronaropathie chez les porteurs de l'allèle mineur de cette mutation (TC/CC) était de 0,50 (0,26- 0,96; P = 0,038).
In Guadeloupe and Martinique, the low frequency ofcoronary artery disease (CAD) could be related to genetic or ethniefactors and/or specifie distribution ofcardiovascular risk factors (CRFs). Atrial Natriuretic Peptide (ANP) properties and influence of sorne of ANP gene polymorphism that are frequent in populations of African descent could also be involved in CAD occurrence. We retrospectively studied 638 consecutive patients with documented CAO and found a high prevalence of hypertension and diabetes in this population. This study also demonstrated significant differences in the prevalence of CRFs between Afro-Caribbean (AC), Caucasians and Indians migrants. The angiographie analysis of420 patients revealed that in AC, diabetes emerged as the strongest CFR related to the severity ofcoronary lesions while obesity appeared as a protective factor. After transfection by an adenoviral construct carrying the ANP gene, vascular smooth muscle cell proliferation stimulated by 10% fetal calf serum was reduced by 31% and migration by 25%. In vivo, in rat carotid artery model ofvascular injury, neointima formation and intima/media ratio was reduced by 25% and 28% respectively. In a cross-sectional study inc1uding 210 AC diabetics we found an association between rs5065 (22381> C) polymorpbism and the presence of coronary artery disease suggesting that the minor allele could have a protective effect against CAD. The odds ratio for the presence ofCAD in carriers ofthe minor allele ofthis mutation (TC / CC) was 0.50 (0.26-0.96, P = 0.038).

http://www.theses.fr/2012AGUY0553/document

Éditeur(s) : DPLSH : Département Pluridisciplinaire de Lettres, Langues et Sciences humaines G.R.R.E.A. 17/18 : Groupe de Recherches sur les Représentations Européennes de l'Afrique aux XVIIe et XVIIIe siècles CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines Mémorial ACTe
Extrait de : "Les représentations du Noir dans la littérature, l'histoire et les arts européens et américains des XVIIIe, XIXe et début du XXe siècle" : colloque pluridisciplinaire, du 27 février au 2 mars 2013. Université des Antilles et de la Guyane
Description : Le thème central de cette conférence sera l'engagement des artistes et des gens de lettres dans le combat antiesclavagiste. Les ?uvres (peintures, sculptures, arts décoratifs, bas-reliefs, photographies...) proposées lors de l'exposé ont été explicitement réalisées dans une perspective de combat contre la traite, l'esclavage et ses séquelles.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V13036
V13036

Éditeur(s) : HAL CCSD BioScientifica
Résumé : International audience
The general rules established from mammalian species for the regulation of spermatogenesis by gonadotropins may not be fully relevant in fish. Particularly, Fsh is as potent as Lh to stimulate steroidogenesis and the Fsh receptor is expressed in Leydig cells. In seasonal breeders, Fsh is likely the major gonadotropin involved in spermatogenesis onset and Lh is required to support spermatogenesis progression and gamete release. However, the genes that relay the action of Fsh and Lh have been poorly investigated in fish. The present study was aimed at identifying gonadotropin-dependent genes expressed in the testis during fish puberty. We cultured pubertal trout testicular explants for 96 h, with or without gonadotropin, and analyzed transcriptome variations using microarrays. Fsh and Lh had similar effects on a large group of genes while other genes were preferentially regulated by one or the other gonadotropin. We showed that most of the responsive genes were expressed in somatic cells and exhibited relevant patterns during the seasonal reproductive cycle. Some genes preferentially modulated by Lh could be involved in testicular cell fate (pvrl1 and bty) or sperm maturation (ehmt2 and racgap1) and will deserve further examination. Besides Fsh's effects on the steroidogenic pathway, our study demonstrates that Fsh coordinates relevant stimulatory and inhibitory paracrine factors known to regulate early germ cell proliferation and differentiation. Some of these genes belong to major regulatory pathways including the Igf pathway (igf1b/igf3 and igfbp6), the Tgfb pathway (amh, inha, inhba, and fstl3), the Wnt pathway (wisp1), and pleiotrophin (mdka).
ISSN: 0952-5041

inserm-00812401
http://www.hal.inserm.fr/inserm-00812401
DOI : 10.1530/JME-12-0197
PUBMED : 23045716

Éditeur(s) : Archives nationales d'outre-mer
87MIOM13/4
Saint-Domingue

Droits : Reproduction soumise à autorisation des Archives nationales d'outre-mer
http://www.patrimoines-martinique.org/ark:/35569/a011426186902RS0YFP

Éditeur(s) : Archives nationales d'outre-mer
87MIOM9/2
Antilles

Droits : Reproduction soumise à autorisation des Archives nationales d'outre-mer
http://www.patrimoines-martinique.org/ark:/35569/a011426186902ARVI3j