Characterization of a male reproductive transcriptome forPeromyscus eremicus(Cactus mouse)

Abstract

Rodents of the genus Peromyscus have become increasingly utilized models for investigations into adaptive biology. This genus is particularly powerful for research linking genetics with adaptive physiology or behaviors, and recent research has capitalized on the unique opportunities afforded by the ecological diversity of these rodents. Well characterized genomic and transcriptomic data is intrinsic to explorations of the genetic architecture responsible for ecological adaptations. Therefore, this study characterizes the transcriptome of three male reproductive tissues (testes, epididymis and vas deferens) of Peromyscus eremicus (Cactus mouse), a desert specialist. The transcriptome assembly process was optimized in order to produce a high quality and substantially complete annotated transcriptome. This composite transcriptome was generated to characterize the expressed transcripts in the male reproductive tract of P. eremicus, which will serve as a crucial resource for future research investigating our hypothesis that the male Cactus mouse possesses an adaptive reproductive phenotype to mitigate water-loss from ejaculate. This study reports genes under positive selection in the male Cactus mouse reproductive transcriptome relative to transcriptomes from Peromyscus maniculatus (deer mouse) and Mus musculus. Thus, this study expands upon existing genetic research in this species, and we provide a high quality transcriptome to enable further explorations of our proposed hypothesis for male Cactus mouse reproductive adaptations to minimize seminal fluid loss.

Characterizing the reproductive transcriptomic correlates of acute dehydration in males in the desert-adapted rodent,Peromyscus eremicus

“…This leads us to further support the hypothesis originally proposed by Marra et al [32] that this protein family is intrinsic to osmoregulation in desert rodents. Indeed, the findings of MacManes and Eisen [41], Kordonowy and MacManes [33], and MacManes [35] also lend support to the essential role of solute carrier proteins for maintaining homeostasis in the desert specialized cactus mouse.…”

“…Another member of this family, Solute carrier family 2 member 9 (Slc2A9), has been found to be undergoing positive selection in studies on kidney transcriptomes of cactus mouse [41] and of other desert rodents [32]. Our previous work with the male reproductive transcriptome of cactus mouse found evidence for positive selection in two additional solute carrier proteins: Slc15a3 and Slc47a1 [33]. A recent differential gene expression study in cactus mouse kidneys found that Slc2A1 and Slc8A1 also showed responses to acute dehydration [35].…”

“…The testes transcripts were assembled with alternative methodologies utilizing several optimization procedures to produce a high-quality transcriptome; however, the permutations of this assembly process are described extensively elsewhere [33,56]. The testes transcriptome we selected was constructed as described below.…”

“…Research in another desert-adapted rodent, Peromyscus eremicus (cactus mouse), has followed a somewhat different trajectory; however, it too has only pursued survival oriented physiological mechanisms (but see [33][34][35]). The ecology, physiology and behaviors of the cactus mouse in comparison with other Peromyscus species were summarized in 1968 [36], and the relationships between basal metabolic rate, body mass, and evaporative water loss were reviewed several decades later [37].…”

“…However, the transcriptomic resources available for this species extend considerably beyond renal tissue; transcripts from cactus mouse (as well as numerous other Peromyscus species) have been heavily utilized to pursue questions related to multiple aspects of evolutionary biology (reviewed in [5,7]). Current investigations into cactus mouse desert-adaptive renal physiology include transcriptomic analyses [35]; however, we extended this genetic approach by shifting the focus from adaptions for survival to include physiological adaptations for reproductive success [33]. The cactus mouse is an ideal system for investigating dehydration effects on reproduction, as well as potential reproductive adaptations for drought, given decades of study of reproductive biology, as well as the more recent development of transcriptomic resources that include male reproductive tissues.…”