Retention of functional variation despite extreme genomic erosion: MHC allelic repertoires in the Lynx genus

BMC Evolutionary Biology

Research Article

Alexander P. Saveljev¹  Elena Marmesat²  José A. Godoy²  Ivan V. Seryodkin³  Krzysztof Schmidt⁴ 

[1] Department of Animal Ecology, Russian Research Institute of Game Management and Fur Farming, 79 Preobrazhenskaya Str, 610000, Kirov, Russia;Department of Integrative Ecology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio, 26, 41092, Sevilla, Spain;Laboratory of Ecology and Conservation of Animals, Pacific Institute of Geography of Far East Branch of Russian Academy of Sciences, 7 Radio Street, 690041, Vladivostok, Russia;Far Eastern Federal University, 8 Sukhanova Street, 690091, Vladivostok, Russia;Mammal Research Institute, Polish Academy of Sciences, 17-230, Białowieża, Poland;

关键词: Mhc;    Lynx;    Balancing selection;    Natural selection;    Genetic functional diversity;    Bottleneck;    Drift;    Iberian lynx;    Conservation genetics;    Recombination;   

DOI  :  10.1186/s12862-017-1006-z

 received in 2017-04-10, accepted in 2017-06-23,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundDemographic bottlenecks erode genetic diversity and may increase endangered species’ extinction risk via decreased fitness and adaptive potential. The genetic status of species is generally assessed using neutral markers, whose dynamic can differ from that of functional variation due to selection. The MHC is a multigene family described as the most important genetic component of the mammalian immune system, with broad implications in ecology and evolution. The genus Lynx includes four species differing immensely in demographic history and population size, which provides a suitable model to study the genetic consequences of demographic declines: the Iberian lynx being an extremely bottlenecked species and the three remaining ones representing common and widely distributed species. We compared variation in the most variable exon of the MHCI and MHCII-DRB loci among the four species of the Lynx genus.ResultsThe Iberian lynx was characterised by lower number of MHC alleles than its sister species (the Eurasian lynx). However, it maintained most of the functional genetic variation at MHC loci present in the remaining and genetically healthier lynx species at all nucleotide, amino acid, and supertype levels.ConclusionsSpecies-wide functional genetic diversity can be maintained even in the face of severe population bottlenecks, which caused devastating whole genome genetic erosion. This could be the consequence of divergent alleles being retained across paralogous loci, an outcome that, in the face of frequent gene conversion, may have been favoured by balancing selection.

【 授权许可】

CC BY   
© The Author(s). 2017