Data from: Characterization of the transcriptome, nucleotide sequence polymorphism, and natural selection in the desert adapted mouse Peromyscus eremicus

As a direct result of intense heat and aridity, deserts are thought to be among the most harsh of environments, particularly for their mammalian inhabitants. Given that osmoregulation can be challenging for these animals, with failure resulting in death, strong selection should be observed on genes related to the maintenance of water and solute balance. One such animal, Peromyscus eremicus, is native to the desert regions of the southwest United States and may live its entire life without oral fluid intake. As a first step toward understanding the genetics that underlie this phenotype, we present a characterization of the P. eremicus transcriptome. We assay four tissues (kidney, liver, brain, testes) from a single individual and supplement this with population level renal transcriptome sequencing from 15 additional animals. We identified a set of transcripts undergoing both purifying and balancing selection based on estimates of Tajima’s D. In addition, we used the branch-site test to identify a transcript—Slc2a9, likely related to desert osmoregulation—undergoing enhanced selection in P. eremicus relative to a set of related non-desert rodents.由于极端高温与干旱的直接作用，沙漠被认为是最为严苛的环境之一，对栖息其中的哺乳动物而言尤为如此。鉴于此类动物的渗透压调节（osmoregulation）过程往往极具挑战，一旦调节失败便会导致死亡，因此与水分及溶质平衡维持相关的基因应当受到强烈的选择压力。其中一类物种为荒漠鹿鼠（Peromyscus eremicus），它们原产于美国西南部的沙漠区域，甚至可以终生无需经口摄入液体即可存活。为解析该表型背后的遗传机制，本研究首先对荒漠鹿鼠的转录组（transcriptome）进行了表征分析。我们对单只个体的四种组织（肾脏、肝脏、大脑、睾丸）进行了转录组检测，并补充纳入了另外15只个体的肾脏群体转录组测序数据。基于田岛D检验（Tajima's D）的估算结果，我们鉴定出了一套同时经历纯化选择与平衡选择的转录本。此外，我们通过分支位点检验（branch-site test）鉴定到了一个转录本Slc2a9——该基因可能与沙漠环境下的渗透压调节相关——相较于一组亲缘关系相近的非沙漠啮齿类，荒漠鹿鼠中的该转录本受到了更强的选择压力。