State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, Lanzhou University, 730000 Lanzhou, China;
Institute of Evolution, University of Haifa, 3498838 Haifa, Israel.
Proc Natl Acad Sci U S A. 2020 Dec 22;117(51):32499-32508. doi: 10.1073/pnas.2018123117. Epub 2020 Dec 4.
Speciation mechanisms remain controversial. Two speciation models occur in Israeli subterranean mole rats, genus : a regional speciation cline southward of four peripatric climatic chromosomal species and a local, geologic-edaphic, genic, and sympatric speciation. Here we highlight their genome evolution. The five species were separated into five genetic clusters by single nucleotide polymorphisms, copy number variations (CNVs), repeatome, and methylome in sympatry. The regional interspecific divergence correspond to Pleistocene climatic cycles. Climate warmings caused chromosomal speciation. Triple effective population size, , declines match glacial cold cycles. Adaptive genes evolved under positive selection to underground stresses and to divergent climates, involving interspecies reproductive isolation. Genomic islands evolved mainly due to adaptive evolution involving ancient polymorphisms. Repeatome, including both CNV and LINE1 repetitive elements, separated the five species. Methylation in sympatry identified geologically chalk-basalt species that differentially affect thermoregulation, hypoxia, DNA repair, P53, and other pathways. Genome adaptive evolution highlights climatic and geologic-edaphic stress evolution and the two speciation models, peripatric and sympatric.
物种形成机制仍存在争议。在以色列地下鼹鼠属中存在两种物种形成模式：一种是区域性物种形成梯度，其范围向南延伸至四个边缘气候染色体物种；另一种是局部的、地质土壤的、基因的和同域的物种形成。在这里，我们强调它们的基因组进化。通过单核苷酸多态性、拷贝数变异 (CNV)、重复组和甲基组，这五个物种在同域中被分为五个遗传聚类。区域性种间分化与更新世气候循环相对应。气候变暖导致了染色体物种形成。三倍有效种群大小 ，与冰川冷循环相匹配。适应地下压力和不同气候的正选择进化出了适应性基因，涉及种间生殖隔离。基因组岛屿主要由于涉及古老多态性的适应性进化而进化。重复组包括 CNV 和 LINE1 重复元件，将这五个物种分开。同域中的甲基化鉴定出了地质上的白垩-玄武岩物种，这些物种对体温调节、缺氧、DNA 修复、P53 和其他途径产生了不同的影响。基因组适应性进化突出了气候和地质土壤压力的进化以及两种物种形成模式，即边缘和同域。
