Deciphering the molecular architecture of the coat colour variability in a European rabbit population
Résumé
Understanding the molecular mechanism of coloration has been the goal of many genetic and evolutionary studies in a broad number of species. Nevertheless, most of our current knowledge is restricted to colour traits exhibiting relatively simple discrete variation and inheritance patterns. More than a hundred of genes are involved in coloration traits in rodents and many mutations have been identified. In the European rabbit (Oryctolagus cuniculus), different coat colours have been selected through domestication and are nowadays fixed in specific breeds. Although numerous mutations affecting coat colour have been discovered in various rabbit breeds, additional variants have still to be identified. Despite the evolution of technologies through the genomics era, understanding the molecular architecture of such complex phenotypes still remains a challenge. Here, we propose a genome-wide investigation of coat colour using rabbit high-density SNP array. We performed genome-wide association studies (GWAS) considering the variation of coat colour as quantitative and binary phenotypes. We identified several significant SNPs marking loci already known to affect coat colour as well as in a few other chromosome regions not yet described to affect this phenotype in rabbits (e.g. a genomic region on chromosome 14). Moreover, we determined the best model of inheritance for each region associated to coat colour. Our results bring new insights into the molecular architecture of the coloration phenotype pinpointing its oligogenic determinism.