Contributors: Lineberger Comprehensive Cancer Center (UNC Lineberger); University of North Carolina Chapel Hill (UNC); University of North Carolina System (UNC)-University of North Carolina System (UNC); Carolina Center for Genome Sciences; Institut des Sciences de l'Evolution de Montpellier (UMR ISEM); Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE); Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS); The Jackson Laboratory Bar Harbor (JAX); Island Conservation; The University of Queensland (UQ All campuses : Brisbane, Dutton Park Gatton, Herston, St Lucia and other locations ); Università degli Studi di Roma "La Sapienza" = Sapienza University Rome (UNIROMA); Elon University NC, USA; University of North Carolina System (UNC); Leibniz Institute for Zoo and Wildlife Research (IZW); Leibniz Association; National Institute of Environmental Health Sciences Durham, NC, USA (NIEHS-NIH); National Institutes of Health Bethesda, MD, USA (NIH); Centre for Environmental and Marine Studies Aveiro (CESAM); Universidade de Aveiro; Universidade de Lisboa = University of Lisbon (ULISBOA); University of California Riverside (UC Riverside); University of California (UC); Department of Biology Patras; University of Patras; Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires (CONICET); Universidad Nacional de Misiones; Universität Zürich Zürich = University of Zurich (UZH); Ondokuz Mayis University (OMU); National Institute on Alcohol Abuse and Alcoholism (NIAAA); Fondazione Edmund Mach - Edmund Mach Foundation Italie (FEM); Department of Computer Science Chapel Hill; Universitat de Barcelona (UB); National Institute of Diabetes and Digestive and Kidney Diseases Bethesda; Department of Ecology and Evolutionary Biology Ithaca; Cornell University New York; Mahidol University Bangkok; Texas A&M University College Station; Universitat Autònoma de Barcelona = Autonomous University of Barcelona = Universidad Autónoma de Barcelona (UAB)
نبذة مختصرة : International audience ; A selective sweep is the result of strong positive selection driving newly occurring or standing genetic variants to fixation, and can dramatically alter the pattern and distribution of allelic diversity in a population. Population-level sequencing data have enabled discoveries of selective sweeps associated with genes involved in recent adaptations in many species. In contrast, much debate but little evidence addresses whether "selfish" genes are capable of fixation-thereby leaving signatures identical to classical selective sweeps-despite being neutral or deleterious to organismal fitness. We previously described R2d2, a large copy-number variant that causes nonrandom segregation of mouse Chromosome 2 in females due to meiotic drive. Here we show population-genetic data consistent with a selfish sweep driven by alleles of R2d2 with high copy number (R2d2(HC)) in natural populations. We replicate this finding in multiple closed breeding populations from six outbred backgrounds segregating for R2d2 alleles. We find that R2d2(HC) rapidly increases in frequency, and in most cases becomes fixed in significantly fewer generations than can be explained by genetic drift. R2d2(HC) is also associated with significantly reduced litter sizes in heterozygous mothers, making it a true selfish allele. Our data provide direct evidence of populations actively undergoing selfish sweeps, and demonstrate that meiotic drive can rapidly alter the genomic landscape in favor of mutations with neutral or even negative effects on overall Darwinian fitness. Further study will reveal the incidence of selfish sweeps, and will elucidate the relative contributions of selfish genes, adaptation and genetic drift to evolution.
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