27 research outputs found
New perspectives on the evolution of within-individual genome variation and germline/soma distinction
Genomes can vary significantly even within the same individual. The underlying mechanisms are manifold, ranging from somatic mutation and recombination, development-associated ploidy changes and genetic bottlenecks, over to programmed DNA elimination during germline/soma differentiation. In this perspective piece, we briefly review recent developments in the study of within-individual genome variation in eukaryotes and prokaryotes. We highlight a Society for Molecular Biology and Evolution 2020 virtual symposium entitled "Within-individual genome variation and germline/soma distinction" and the present Special Section of the same name in Genome Biology and Evolution, together fostering cross-taxon synergies in the field to identify and tackle key open questions in the understanding of within-individual genome variation
RAD-QTL mapping reveals both genome-level parallelism and different genetic architecture underlying the evolution of body shape in Lake Whitefish (Coregonus clupeaformis) species pairs
Parallel changes in body shape may evolve in response to similar environmental conditions, but whether such parallel phenotypic changes share a common genetic basis is still debated. The goal of this study was to assess whether parallel phenotypic changes could be explained by genetic parallelism, multiple genetic routes, or both. We first provide evidence for parallelism in fish shape by using geometric morphometrics among 300 fish representing five species pairs of Lake Whitefish. Using a genetic map comprising 3438 restriction site-associated DNA sequencing single-nucleotide polymorphisms, we then identified quantitative trait loci underlying body shape traits in a backcross family reared in the laboratory. A total of 138 body shape quantitative trait loci were identified in this cross, thus revealing a highly polygenic architecture of body shape in Lake Whitefish. Third, we tested for evidence of genetic parallelism among independent wild populations using both a single-locus method (outlier analysis) and a polygenic approach (analysis of covariation among markers). The single-locus approach provided limited evidence for genetic parallelism. However, the polygenic analysis revealed genetic parallelism for three of the five lakes, which differed from the two other lakes. These results provide evidence for both genetic parallelism and multiple genetic routes underlying parallel phenotypic evolution in fish shape among populations occupying similar ecological niches.Keywords : Adaptive radiation, Parallel evolution, Fish body shape, Geometric morphometrics, Genotyping-by-sequencing
Les consĂ©quences de la pandĂ©mie sur la santĂ© globale des populations universitaires. Stress, adaptation et soutien social. Faits saillants â Phase 1 â Feuillet No 5
Les consĂ©quences de la pandĂ©mie sur la santĂ© globale des populations universitaires. Qui sont les participants ? Faits saillants â Phase 1 â Feuillet No 1
Les consĂ©quences de la pandĂ©mie sur la santĂ© globale des populations universitaires. Que connait-on de lâĂ©tat de santĂ© mentale des rĂ©pondants ? Faits saillants â Phase 1 â Feuillet No 2
Les consĂ©quences de la pandĂ©mie sur la santĂ© globale des populations universitaires. Quelles sont les rĂ©percussions Ă©conomiques et professionnelles de la pandĂ©mie sur les rĂ©pondants? Faits saillants â Phase 1 â Feuillet No 6
Les consĂ©quences de la pandĂ©mie sur la santĂ© globale des populations universitaires. De quelles maniĂšres les participants perçoivent-ils leurs milieux universitaires? Faits saillants â Phase 1 â Feuillet No 7
Santé mentale et population universitaire : un laboratoire-vivant au service de la communauté : rapport de recherche
Cette Ă©tude a trois objectifs : 1) Identifier les principaux enjeux de santĂ© des Ă©tudiant·es et des employé·es de lâUQAC en contexte pandĂ©mique, 2) RĂ©pertorier lâensemble des mesures de soutien Ă la santĂ© mises Ă la disposition des Ă©tudiant·es et des employé·es de lâUQAC, et 3) Identifier de nouvelles solutions Ă mettre en place afin de pallier les manques et de soutenir les Ă©tudiant·es et les employé·es de lâUQAC
Cooperation of breast cancer proteins PALB2 and piccolo BRCA2 in stimulating homologous recombination.
Inherited mutations in human PALB2 are associated with a predisposition to breast and pancreatic cancers. PALB2's tumor-suppressing effect is thought to be based on its ability to facilitate BRCA2's function in homologous recombination. However, the biochemical properties of PALB2 are unknown. Here we show that human PALB2 binds DNA, preferentially D-loop structures, and directly interacts with the RAD51 recombinase to stimulate strand invasion, a vital step of homologous recombination. This stimulation occurs through reinforcing biochemical mechanisms, as PALB2 alleviates inhibition by RPA and stabilizes the RAD51 filament. Moreover, PALB2 can function synergistically with a BRCA2 chimera (termed piccolo, or piBRCA2) to further promote strand invasion. Finally, we show that PALB2-deficient cells are sensitive to PARP inhibitors. Our studies provide the first biochemical insights into PALB2's function with piBRCA2 as a mediator of homologous recombination in DNA double-strand break repair
PALB2, une protéine à la croisée de l'anémie de Fanconi, du cancer du sein et de la réparation de l'ADN : caractérisation biochimique
Tableau dâhonneur de la FacultĂ© des Ă©tudes supĂ©rieures et postdoctorales, 2009-2010L'anĂ©mie de Fanconi est une maladie gĂ©nĂ©tique rĂ©cessive rare se manifestant par des troubles dĂ©veloppementaux, sanguins, et une prĂ©disposition Ă certains cancers. Les cellules de patients montrent une sensibilitĂ© Ă©levĂ©e aux agents causant des ponts interbrins dans l'ADN, dont la rĂ©paration implique l'activation de la recombinaison homologue. La prĂ©sence de PALB2, mutĂ©e dans l'anĂ©mie de Fanconi, est nĂ©cessaire pour la localisation chromatinienne de BRCA2 et RAD51, en rĂ©ponse aux dommages Ă l'ADN. Comme BRCA2, PALB2 est un gĂšne de prĂ©disposition au cancer du sein. Il devient important de mieux comprendre le rĂŽle de PALB2/FANCN dans la recombinaison homologue. Nous avons entrepris la caractĂ©risation de l'activitĂ© biochimique de PALB2 en la purifiant, de mĂȘme qu'un mutant associĂ© au cancer du sein, PALB2Q775X, afin de clarifier son rĂŽle dans la rĂ©paration de l'ADN. Les donnĂ©es obtenues suggĂšrent que PALB2 possĂšde les caractĂ©ristiques d'un mĂ©diateur de la recombinaison homologue, ce qui en fait une cible privilĂ©giĂ©e dans le dĂ©veloppement de thĂ©rapies anticancĂ©reuses dans le futur