AbstractAs one of the most successful domesticated animals in the Neolithic age,
sheep gradually migrated all over the world with human activities. During the
domestication process, remarkable changes have taken place in morphology,
physiology, and behavior, resulting in different breeds with different
characters via artificial and natural selection. However, the genetic
background responsible for these phenotypic variations remains largely
unclear. Here, we used whole genome resequencing technology to compare and
analyze the genome differences between Asiatic mouflon wild sheep (Ovis orientalis) and Hu
sheep (Ovis aries). A total of 755 genes were positively selected in the process of
domestication and selection, and the genes related to sensory perception had
directional evolution in the autosomal region, such asOPRL1, LEF1, TAS1R3, ATF6, VSX2, MYO1A, RDH5, and some novel
genes. A missense mutation of c.T722C/p.M241T in exon 4 ofRDH5existing in sheep
were found, and theTallele was completely fixed in Hu sheep. In addition, the
mutation with theCallele reduced the retinol dehydrogenase activity encoding
byRDH5, which can impair retinoic acid metabolism and further influenced the visual
cycle. Overall, our results showed significant enrichment for positively
selected genes involved in sensory perception development during sheep
domestication;RDH5and its variants may be related to the retinal degeneration
in sheep. We infer that the wild sheep ancestors with weaker visual sensitivity
were weeded out by humans, and the mutation was selective, swept by the dual
pressures of natural and artificial selection.