Hu Meng-Yuan, Yu Jun, Lin Jian-Qing, Fang Sheng-Guo
MOE Key Laboratory of Biosystems Homeostasis and Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, China.
Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou, China.
Front Genet. 2022 Mar 31;13:843884. doi: 10.3389/fgene.2022.843884. eCollection 2022.
MicroRNA (miRNA) is a category of single-stranded non-coding small RNA (sRNA) that regulates gene expression by targeting mRNA. It plays a key role in the temperature-dependent sex determination of Chinese alligator (), a reptile whose sex is determined solely by the temperature during the incubation period and remains stable thereafter. However, the potential function of miRNAs in the gonads of adult Chinese alligators is still unclear. Here, we prepared and sequenced sRNA libraries of adult female and male alligator gonads, from breeding (in summer) and hibernating (in winter) animals. We obtained 130 conserved miRNAs and 683 novel miRNAs, which were assessed for sex bias in summer and winter; a total of 65 miRNAs that maintained sex bias in both seasons were identified. A regulatory network of sex-biased miRNAs and genes was constructed. Sex-biased miRNAs targeted multiple genes in the meiosis pathway of adult Chinese alligator oocytes and the antagonistic gonadal function maintenance pathway, such as , , , and . Our study emphasizes the function of miRNA in the epigenetic mechanisms of sex maintenance in crocodilians.
微小RNA（miRNA）是一类单链非编码小RNA（sRNA），通过靶向mRNA来调控基因表达。它在扬子鳄的温度依赖性性别决定中起关键作用，扬子鳄是一种爬行动物，其性别仅由孵化期的温度决定，此后保持稳定。然而，miRNA在成年扬子鳄性腺中的潜在功能仍不清楚。在此，我们制备并测序了成年雌性和雄性扬子鳄性腺的sRNA文库，这些样本分别来自繁殖期（夏季）和冬眠期（冬季）的动物。我们获得了130个保守miRNA和683个新miRNA，并评估了它们在夏季和冬季的性别偏向性；共鉴定出65个在两个季节都保持性别偏向性的miRNA。构建了性别偏向性miRNA和基因的调控网络。性别偏向性miRNA靶向成年扬子鳄卵母细胞减数分裂途径和拮抗性腺功能维持途径中的多个基因，如、、、和。我们的研究强调了miRNA在鳄鱼性别维持表观遗传机制中的作用。
