Tibetan pigs are an important indigenous genetic resource on the Qinghai-Tibetan Plateau, but their population history remains unclear. Here, we analyzed whole-genome resequencing data from 29 Tibetan pigs and 69 wild boars from different regions to investigate their genetic structure and origin. Population structure analyses showed that Tibetan pigs formed a distinct genetic cluster, but clear substructure was present among the four Tibetan pig groups. Demographic analyses indicated that all Tibetan pigs shared a similar deep ancestral background, whereas the Tibetan population from Tibet (TT) showed a distinct recent demographic trajectory relative to the other Tibetan pig groups. Model inference based on multidimensional site frequency spectra further supported a mixed origin of TT from northern and southern Asian wild boar-related ancestral components. In contrast, the other three Tibetan pig groups were best explained as lineages derived from TT after its formation. We also detected a persistent western Eurasian-related excess-sharing signal in TT, consistent with potential introgression. Selection scans identified candidate genes and pathways potentially related to hypoxia adaptation, cardiovascular function, and lung development.
Xue et al. (Mon,) studied this question.