凸颅鼢鼠属快速物种形成及种间基因交流的基因组机制研究

The complex geographical and climatic features of Qinghai–Tibet Plateau caused by recent rapid uplift and quaternary ice age, is the major driving forces of adaptive evolution and speciation for native species. Over the last 6 million years, five species of genus Eospalax with notable morphological and habitat differences were formed due to rapid speciation. At the same time, the extensive sympatric and parapatric distribution of these five species also implies the possibility of interspecific gene flow. In this project, we aim to explore the genomic mechanisms of rapid speciation in genus Eospalax and evaluate the importance of gene flow and adaptive evolution during this process. On the other hand, the identification of genomic loci that displays either extensive or limited gene flow in the genome of hybrid populations, will give us new insights into the driving forces of interspecific gene flow and the genetic mechanisms of reproductive isolation. Based on these results, we will improve our understanding of the genetic mechanisms of speciation in Qinghai–Tibet Plateau, as well as get new insights into the process of speciation.

青藏高原由于近期快速隆升并受第四纪冰期的影响而产生的复杂地理和气候特征，成为生物适应性进化及物种形成的重要驱动因素。近六百万年内，凸颅鼢鼠属在青藏高原东北部边缘发生快速物种形成，并形成了在形态、栖息环境等方面差异显著的6个物种。同时，这6个物种之间存在广泛的同域、邻域分布并可能产生跨物种基因交流。本研究以凸颅鼢鼠属物种及其代表性群体为研究对象，采用群体基因组学的方法，并结合表型数据，研究凸颅鼢鼠属快速物种形成的基因组机制，并探讨基因流及适应性进化在这过程中的作用；另一方面，对杂交群体基因组中发生频繁基因交流及阻碍基因交流的遗传组分进行鉴定，解析种间基因交流的进化驱动力及建立并维持生殖隔离的遗传机制。这些研究结果不仅加深对青藏高原这一特殊地区动物物种形成遗传学机制的理解，还将促进对物种形成机制的新认识。

本项目基于全基因组测序构建了凸颅鼢鼠属（Eospalax）的系统发生关系，解析了该属物种适应辐射的基本情况。该结果也通过结合肠道微生物及环境微生物群落分析得到验证。适应性渗透在物种形成及适应性进化过程中的作用近年来受到关注。我们基于表型及基因型分析，解析了高海拔甘肃鼢鼠与高原鼢鼠间的基因交流，并建立了适应性表型与基因渗透区域的关联，表明适应性辐射在甘肃鼢鼠适应高海拔环境过程中起到重要的作用。