Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA.
Biomedical Sciences, University of Missouri, Columbia, MO, 65211, USA.
BMC Genomics. 2019 Jan 25;20(1):87. doi: 10.1186/s12864-019-5426-6.
Brain sexual differentiation is sculpted by precise coordination of steroid hormones during development. Programming of several brain regions in males depends upon aromatase conversion of testosterone to estrogen. However, it is not clear the direct contribution that Y chromosome associated genes, especially sex-determining region Y (Sry), might exert on brain sexual differentiation in therian mammals. Two species of spiny rats: Amami spiny rat (Tokudaia osimensis) and Tokunoshima spiny rat (T. tokunoshimensis) lack a Y chromosome/Sry, and these individuals possess an XO chromosome system in both sexes. Both Tokudaia species are highly endangered. To assess the neural transcriptome profile in male and female Amami spiny rats, RNA was isolated from brain samples of adult male and female spiny rats that had died accidentally and used for RNAseq analyses.
RNAseq analyses confirmed that several genes and individual transcripts were differentially expressed between males and females. In males, seminal vesicle secretory protein 5 (Svs5) and cytochrome P450 1B1 (Cyp1b1) genes were significantly elevated compared to females, whereas serine (or cysteine) peptidase inhibitor, clade A, member 3 N (Serpina3n) was upregulated in females. Many individual transcripts elevated in males included those encoding for zinc finger proteins, e.g. zinc finger protein X-linked (Zfx).
This method successfully identified several genes and transcripts that showed expression differences in the brain of adult male and female Amami spiny rat. The functional significance of these findings, especially differential expression of transcripts encoding zinc finger proteins, in this unusual rodent species remains to be determined.
大脑的性别分化是由发育过程中类固醇激素的精确协调塑造的。雄性的几个大脑区域的编程依赖于芳香化酶将睾酮转化为雌激素。然而，目前尚不清楚 Y 染色体相关基因（尤其是性别决定区 Y[Sry]）对真兽类哺乳动物大脑性别分化的直接影响。两种棘鼠：奄美棘鼠（Tokudaia osimensis）和德之岛棘鼠（T. tokunoshimensis）缺乏 Y 染色体/Sry，这两种棘鼠在两性中均具有 XO 染色体系统。这两个 Tokudaia 物种都高度濒危。为了评估雄性和雌性奄美棘鼠的大脑转录组图谱，我们从意外死亡的成年雄性和雌性棘鼠的大脑样本中分离 RNA，并用于 RNAseq 分析。
RNAseq 分析证实，雄性和雌性之间有几个基因和个体转录本存在差异表达。在雄性中，与雌性相比，精囊分泌蛋白 5（Svs5）和细胞色素 P450 1B1（Cyp1b1）基因显著上调，而丝氨酸（或半胱氨酸）肽酶抑制剂，A 族，成员 3N（Serpina3n）在雌性中上调。许多在雄性中上调的个体转录本包括编码锌指蛋白的基因，例如锌指蛋白 X 连锁（Zfx）。
本方法成功鉴定出在成年雄性和雌性奄美棘鼠大脑中表达存在差异的几个基因和转录本。这些发现的功能意义，特别是编码锌指蛋白的转录本的差异表达，在这种不寻常的啮齿动物物种中仍有待确定。
