Population Genetic Analysis of Ten Geographically Isolated Tibetan Pig Populations

Abstract

Several geographically isolated populations of Tibetan pigs inhabit the high-altitude environment of the Tibetan Plateau. Their genetic relationships, contribution to the pool of genetic diversity, and their origin of domestication are unclear. In this study, whole-genome re-sequencing data from 10 geographically isolated Tibetan pig populations were collected and analyzed. Population genetic analyses revealed limited genetic differentiation among the Tibetan pig populations. Evidence from deleterious variant analysis indicated that population-specific deleterious variants were the major component of all mutational loci. Contribution to the meta-population was largest in the TT (Qinghai-Tibet Plateau) population, based on gene diversity or allelic diversity. Selective sweep analysis revealed numerous genes, including RXFP1, FZD1, OR1F1, TBX19, MSTN, ESR1, MC1R, HIF3A, and EGLN2 which are involved in lung development, hard palate development, coat color, hormone metabolism, facial appearance, and perception of smell. These findings increase our understanding of the origins and domestication of the Tibetan pig, and help optimize the strategy for their conservation.