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.

受极端高温与干旱的直接影响，沙漠堪称地球环境中最为严苛的生境之一，对栖息于此的哺乳动物而言尤为如此。鉴于渗透压调节 (osmoregulation) 对这类动物本就极具挑战性，调节失衡甚至会引发死亡，因此与水分和溶质稳态维持相关的基因理应受到强烈的自然选择压力。其中一类代表性物种为荒漠鹿鼠 (Peromyscus eremicus)，其原生分布范围涵盖美国西南部的沙漠区域，甚至可终生无需通过口腔摄取液体即可存活。为解析该独特表型背后的遗传机制，本研究首先对荒漠鹿鼠的转录组 (transcriptome) 开展了系统表征。我们对单只个体的四种组织（肾脏、肝脏、大脑、睾丸）进行了转录组测序，并补充了另外15只个体的肾脏群体转录组测序数据。基于塔伊马D值 (Tajima’s D) 的计算结果，我们鉴定出了一批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) 鉴定出一条转录本——Slc2a9，其可能与荒漠环境下的渗透压调节相关——相较于一系列亲缘关系较近的非沙漠啮齿类，该转录本在荒漠鹿鼠中受到了更强的选择压力。