Invasion de l'aire de la sous-espèce marine par la sous-espèce continentale du Grand-Cormoran Phalacrocorax carbo

communication oral

Population structuring of the Cormorant in Europe: Two or three subspecies?

International audienc

Population structure and ecological specialisation in great cormorant in geographical expansion within Europe

The Great Cormorant (Phalacrocorax carbo), actually in expansion is a large colonial piscivorous migrating waterbird. In Europe, two sub-species, carbo and sinensis, are distinguished according to morphological, ecological and geographical criteria. This work has focused on the evolutionary history of populations, the validity of the subdivision in two sub-species, and the ecological specialisation. The main results are: (i) the phylogeographical study shows the existence of a third sub-species in Europe and the convergence of the populations to the western part of Europe; (ii) the analysis of the population structure (microsatellites) show pattern of isolation by distance, with an effect of long-dispersal distance linked to the migratory axis; (iii) the monitoring of the breeding success show that the sinensis subspecies is better adapted to the inland habitat than carbo subspecies.Le Grand Cormoran (Phalacrocorax carbo), est un oiseau colonial piscivore migrateur de grande taille, actuellement en expansion. En Europe, deux sous-espèces, carbo et sinensis, sont distinguées : critères morphologiques, écologiques et géographiques. Ce travail visait à étudier l'histoire évolutive des populations, à tester la pertinence de la sub-division en deux sous-espèces et à vérifier l'hypothèse de spécialisation écologique, grâce à des méthodes moléculaire et de suivi sur le terrain. Les résultats majeurs sont : (i) l'étude phylogéographique (ADNmt) montre l'existence d'une 3^ème sous-espèce européenne et la convergence des populations vers l'ouest de l'Europe ; (ii) l'analyse de la structure de population (microsatellites) montre une isolation par la distance, avec un effet de dispersion longue-distance, en lien avec la migration ; (iii) l'étude du succès reproducteur montre que la sous-espèce sinensis est mieux adaptée au milieu continental que carbo (spécialisation écologique).RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Ecological segregation and population structuring of the Cormorant Phalacrocorax carbo in Europe, in relation to the recent introgression of continental and marine subspecies.

Populations of the ‘‘continental'' Great Cormorant P. c. sinensis have expanded from north-eastern Europe towards the western part of the range of the ‘‘marine'' P. c. carbo breeding in the United Kingdom and France. The aim of the study was to test the hypothesis of ecological segregation between subspecies by analysing the structuring of the European populations. Sequencing the mtDNA of 231 birds belonging to 20 colonies revealed 38 haplotypes based on 25 polymorphic sites (5.76% sequence divergence). P. c. sinensis (‘‘S'') was well confirmed, but usual P. c. carbo formed two coastal populations, the real P. c. carbo ‘‘C'' mainly in the western part of the range (United Kingdom, coastal France), and also in Norway and Sardinia, and ‘‘N'', branched to the Japanese Cormorant P. capillatus and probably isolated by glaciations, mainly present in the Nordic range (Norway, but also on the coasts from Sweden to Brittany), we named P. c. norvegicus. In a variable position in the trees but close to C is a group of undetermined origin haplotypes, named U, also present in both traditional ranges. The new tree-nesting colonies in Brittany are clearly a mixture of S and the two clades C and N previously described as P. c. carbo, with a decreasing proportion of C+N between 1993 (67%), 1996 (60%) and 2002 (33%) for the pioneering Grand-Lieu colony. These results confirmed the current introgression of continental populations in the western range, with probable hybridization. Although the subspecies can switch habitats locally due to social behaviour and migrations, the ecological segregation between the two usual subspecies appears to be largely confirmed in Europe

Habitat specialisation affects fitness of the marine and continental Great Cormorant subspecies in a recently evolved sympatric area

International audienceWith the aim of studying ecological specialisation between subspecies, we compared the components of breeding success in individuals of two recently sympatric subspecies, carbo ('marine') and sinensis ('continental'), of the Great Cormorant in a continental colony. The subspecific origin of broods was determined using D-Loop mtDNA and microsatellites. Although there were no differences in clutch size and laying date between the subspecies, mean fledging success was lower for the marine subspecies (-30% according to mtDNA assignment, -38% according to microsatellite assignment) than for the continental subspecies, while mixed breeding pairs had an intermediate fledging success. These results showed that the marine subspecies is less well adapted than the continental one to inland water, which is considered to be the optimal habitat of the continental subspecies. According to these results and to the geographical expansion of the continental subspecies, we suggest that the proportion of marine subspecies in western European inland colonies could decrease when density-dependent competition increases due to saturation

Constitutive autophagy contributes to resistance to TP53-mediated apoptosis in Epstein-Barr virus-positive latency III B-cell lymphoproliferations

International audienc

Genetic Evidence of a Precisely Tuned Dysregulation in the Hypoxia Signaling Pathway during Oncogenesis

International audienceThe classic model of tumor suppression implies that malignant transformation requires full "two-hit"inactivation of a tumor-suppressor gene. However, more recent work in mice has led to the proposal of a"continuum" model that involves more fluid concepts such as gene dosage-sensitivity and tissue specificity.Mutations in the tumor-suppressor gene von Hippel-Lindau (VHL) are associated with a complex spectrum ofconditions. Homozygotes or compound heterozygotes for the R200W germline mutation in VHL have Chuvashpolycythemia, whereas heterozygous carriers are free of disease. Individuals with classic, heterozygous VHLmutations have VHL disease and are at high risk of multiple tumors (e.g., CNS hemangioblastomas, pheochromocytoma,and renal cell carcinoma). We report here an atypical family bearing two VHL gene mutations in cis(R200W and R161Q), together with phenotypic analysis, structural modeling, functional, and transcriptomicstudies of these mutants in comparison with classical mutants involved in the different VHL phenotypes. Wedemonstrate that the complex pattern of disease manifestations observed in VHL syndrome is perfectlycorrelated with a gradient of VHL protein (pVHL) dysfunction in hypoxia signaling pathways. Thus, by studyingnaturally occurring familial mutations, our work validates in humans the "continuum" model of tumorsuppression

As investigações dos fenômenos psíquicos/espirituais no século XIX: sonambulismo e espiritualismo, 1811-1860

Resumo No início do século XIX, investigações sobre a natureza de fenômenos psíquicos/espirituais como transes e supostas aquisições de informações indisponíveis aos canais sensoriais normais geraram grande debate no meio científico. Este artigo discute as principais explicações oferecidas pelos pesquisadores dos fenômenos psíquicos entre 1811 e 1860, concentrando-se nos dois movimentos principais no período: sonambulismo magnético e espiritualismo moderno. As investigações desses fenômenos geraram diversas teorias, sem que se chegasse a consenso, mas trouxeram implicações para a compreensão da mente e de seus transtornos, notadamente na área do inconsciente e da dissociação, constituindo-se como parte importante da história da psicologia e da psiquiatria