State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China.
Mol Biol Evol. 2020 Sep 1;37(9):2616-2629. doi: 10.1093/molbev/msaa113.
Genetic introgression not only provides material for adaptive evolution but also confounds our understanding of evolutionary history. This is particularly true for canids, a species complex in which genome sequencing and analysis has revealed a complex history of admixture and introgression. Here, we sequence 19 new whole genomes from high-altitude Tibetan and Himalayan wolves and dogs and combine these into a larger data set of 166 whole canid genomes. Using these data, we explore the evolutionary history and adaptation of these and other canid lineages. We find that Tibetan and Himalayan wolves are closely related to each other, and that ∼39% of their nuclear genome is derived from an as-yet-unrecognized wolf-like lineage that is deeply diverged from living Holarctic wolves and dogs. The EPAS1 haplotype, which is present at high frequencies in Tibetan dog breeds and wolves and confers an adaptive advantage to animals living at high altitudes, was probably derived from this ancient lineage. Our study underscores the complexity of canid evolution and demonstrates how admixture and introgression can shape the evolutionary trajectories of species.
遗传渗入不仅为适应性进化提供了物质基础，还混淆了我们对进化历史的理解。这在犬科动物中尤其如此，犬科动物是一个物种复杂的群体，基因组测序和分析揭示了它们混合和渗入的复杂历史。在这里，我们对 19 只来自高海拔藏区和喜马拉雅狼和狗的新全基因组进行了测序，并将这些数据与 166 只全犬科基因组的更大数据集进行了组合。利用这些数据，我们探讨了这些和其他犬科血统的进化历史和适应。我们发现，藏区和喜马拉雅狼彼此之间非常接近，它们的核基因组中有约 39%来自一个尚未被识别的狼样谱系，该谱系与现生的全北极狼和狗分化得非常深。EPAS1 单倍型在藏狗品种和狼中高频出现，赋予了生活在高海拔地区的动物一种适应性优势，它可能就是源自这个古老的谱系。我们的研究强调了犬科动物进化的复杂性，并展示了混合和渗入如何塑造物种的进化轨迹。
