Redpath Museum, McGill University, Montreal, QC, Canada.
Department of Biology, McGill University, Montreal, QC, Canada.
J Hered. 2019 Oct 10;110(6):684-695. doi: 10.1093/jhered/esz045.
Identifying genetic variation involved in thermal adaptation is likely to yield insights into how species adapt to different climates. Physiological and behavioral responses associated with overwintering (e.g., torpor) are thought to serve important functions in climate adaptation. In this study, we use 2 isolated Peromyscus leucopus lineages on the northern margin of the species range to identify single nucleotide polymorphisms (SNPs) showing a strong environmental association and test for evidence of parallel evolution. We found signatures of clinal selection in each lineage, but evidence of parallelism was limited, with only 2 SNPs showing parallel allele frequencies across transects. These parallel SNPs map to a gene involved in protection against iron-dependent oxidative stress (Fxn) and to a gene with unknown function but containing a forkhead-associated domain (Fhad1). Furthermore, within transects, we find significant clinal patterns in genes enriched for functions associated with glycogen homeostasis, synaptic function, intracellular Ca2+ balance, H3 histone modification, as well as the G2/M transition of cell division. Our results are consistent with recent literature on the cellular and molecular basis of climate adaptation in small mammals and provide candidate genomic regions for further study.
鉴定与热适应相关的遗传变异可能有助于了解物种如何适应不同的气候。与越冬（如冬眠）相关的生理和行为反应被认为在气候适应中具有重要功能。在这项研究中，我们使用了物种分布北缘的两个孤立的白足鼠（Peromyscus leucopus）谱系，以鉴定出与环境强烈相关的单核苷酸多态性（SNPs），并检验平行进化的证据。我们在每个谱系中都发现了渐渗选择的迹象，但平行进化的证据有限，只有 2 个 SNP 在横截面上显示出平行的等位基因频率。这些平行 SNP 映射到一个参与抵抗铁依赖性氧化应激的基因（Fxn）和一个具有未知功能但包含叉头相关结构域（Fhad1）的基因。此外，在横截面上，我们发现与糖原稳态、突触功能、细胞内 Ca2+平衡、H3 组蛋白修饰以及细胞分裂的 G2/M 过渡相关的功能富集基因存在显著的渐渗模式。我们的研究结果与小型哺乳动物气候适应的细胞和分子基础的最新文献一致，并为进一步研究提供了候选基因组区域。
