Data from: P53 gene discriminates two ecologically divergent sister species of pine voles

Genes with relevant roles in the differentiation of closely-related species are likely to have diverged simultaneously with the species and more accurately reproduce the species tree. The Lusitanian (Microtus lusitanicus) and Mediterranean (M. duodecimcostatus) pine voles are two recently separated sister species with fossorial lifestyles whose different ecological, physiological and morphological phenotypes reflect the better adaptation of M. duodecimcostatus to the underground habitat. Here we asked whether the differentiation of M. lusitanicus and M. duodecimcostatus involved genetic variations within the tumour suppressor p53 gene, given its role in stress-associated responses. We performed a population-genetic analysis through sequencing of exons and introns of p53 in individuals from sympatric and allopatric populations of both the species in the Iberian Peninsula in which a unidirectional introgression of mitochondrial DNA was previously observed. We were able to discriminate the two species to a large extent. We show that M. duodecimcostatus is composed of one genetically unstructured group of populations sharing a P53 protein that carries a mutation in the DNA-binding region not observed in M. lusitanicus, raising the possibility that this mutation may have been central in the evolutionary history of M. duodecimcostatus. Our results provide suggestive evidence for the involvement of a master transcription factor in the separation of M. lusitanicus and M. duodecimcostatus during Microtus radiation in the Quaternary presumably via a differential adaptive role of the novel p53 in M. duodecimcostatus.在近缘物种分化中发挥相关作用的基因，其演化分化大概率与物种分化同步，且能更精准地重现物种树。葡萄牙田鼠（Microtus lusitanicus）与地中海田鼠（M. duodecimcostatus）是两个新近分化的姐妹物种，二者均为穴居生活，其迥异的生态、生理及形态表型，反映出地中海田鼠对地下生境的适应性更优。鉴于肿瘤抑制因子p53（tumour suppressor p53）参与应激相关应答过程，本研究旨在探究二者的物种分化是否涉及该基因的遗传变异。我们对伊比利亚半岛上该两物种种群（同域种群与异域种群）的p53外显子（exons）与内含子（introns）进行测序，开展群体遗传学分析——此前该区域曾被观测到存在单向线粒体DNA（mitochondrial DNA）渐渗现象。本研究得以在较大程度上区分开这两个物种。结果表明，地中海田鼠由一群遗传结构均一的种群构成，其P53蛋白的DNA结合区域存在一处葡萄牙田鼠未携带的突变，这提示该突变可能在地中海田鼠的演化历程中发挥了核心作用。本研究结果提供了提示性佐证，表明在第四纪（Quaternary）田鼠属（Microtus）辐射演化过程中，作为主转录因子的p53可能通过在两个物种间发挥差异化的适应性功能，参与了葡萄牙田鼠与地中海田鼠的物种分化。