背景:内渗反复被证明在物种适应极端环境中起重要作用,然而,渗入如何使具有特殊地下生活方式的啮齿动物适应高海拔尚不清楚。Myospalacinae是一组地下啮齿动物,其中高海拔高原zokors(Eospalaxbaleyi)和低海拔甘肃zokors(E.cansus)在青藏高原(QTP)的草地生态系统中共生分布。一起,它们为研究渗入在低海拔地下啮齿动物适应高海拔中的作用提供了模型。
结果:应用低覆盖率全基因组重测序和群体遗传学分析,我们发现了从高原zokors到甘肃zokors的适应性渗入的证据,这可能有助于后者适应QTP的高海拔环境。我们确定了具有与能量代谢相关功能的阳性选择基因,心血管系统发育,钙离子运输,和对缺氧的反应可能对高原zokors和甘肃zokors高海拔人群适应高原环境做出了重要贡献。
结论:高原杂种低氧适应相关基因的渗入可能在甘肃杂种对高原环境的适应中起作用。我们的研究为了解QTP上物种的适应性进化以及物种渗入在适应高海拔环境中的重要性提供了新的见解。
BACKGROUND: Introgression has repeatedly been shown to play an important role in the adaptation of species to extreme environments, yet how
introgression enables rodents with specialized subterranean lifestyle to acclimatize to high altitudes is still unclear. Myospalacinae is a group of subterranean rodents, among which the high-altitude plateau zokors (Eospalax baileyi) and the low-altitude Gansu zokors (E. cansus) are sympatrically distributed in the grassland ecosystems of the Qinghai-Tibet Plateau (QTP). Together, they provide a model for the study of the role of
introgression in the adaptation of low-altitude subterranean rodents to high altitudes.
RESULTS: Applying low-coverage whole-genome resequencing and population genetics analyses, we identified evidence of adaptive introgression from plateau zokors into Gansu zokors, which likely facilitated the adaptation of the latter to the high-altitude environment of the QTP. We identified positively selected genes with functions related to energy metabolism, cardiovascular system development, calcium ion transport, and response to hypoxia which likely made critical contributions to adaptation to the plateau environment in both plateau zokors and high-altitude populations of Gansu zokors.
CONCLUSIONS: Introgression of genes associated with hypoxia adaptation from plateau zokors may have played a role in the adaptation of Gansu zokors to the plateau environment. Our study provides new insights into the understanding of adaptive evolution of species on the QTP and the importance of
introgression in the adaptation of species to high-altitude environments.