Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu 241000, China; College of Life Sciences, Anhui Normal University, Wuhu 241000, China.
Department of Occupational and Environmental Health, School of Public Health, Wuhan University of Science and Technology, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, China.
Gene. 2018 Dec 15;678:241-251. doi: 10.1016/j.gene.2018.08.007. Epub 2018 Aug 10.
The Chinese concave-eared torrent frog (Odorrana tormota) is the first known non-mammalian vertebrate that can communicate using ultrasound. In this species, females are approximately four times as large as males, in which the female growth rate is obviously higher than that of male. Until now, the molecular mechanisms underlying muscle growth development differences between male and female frogs have not been reported. Here, we integrated mRNA and miRNA expression profiles to reveal growth differences in the hindlimb muscles of 2-year-old frogs. Among 569 differentially expressed genes (DEGs), 69 were associated with muscle growth and regeneration. Fifty-one up-regulated genes in females were potentially involved in promoting muscle growth and regeneration, whereas 18 up-regulated genes in males may lead to muscle growth inhibition and fast-twitch muscle fiber contraction. 244 DEGs were enriched in mTOR and other protein synthesis signaling pathways, and protein degradation pathways, including lysosomal protease, calpain, caspase, and ubiquitin-proteasome system pathways. It may interpret why female muscles grow faster than males. Based on expression differences of genes involved in glycolysis and oxidative metabolism, we speculated that the proportion of slow muscle fiber was higher and that of fast muscle fiber was lower in female compared with male muscle. Additionally, 767 miRNAs were identified, including 217 new miRNAs, and 6248 miRNA-negatively regulated mRNAs were predicted. The miRNA target genes were enriched in pathways related to muscle growth, protein synthesis, and degradation. Thus, in addition to the identified mRNA differential expressions, miRNAs may play other important roles in the differential regulation of hindlimb muscle growth between female and male O. tormota.
中华蟾蜍（Odorrana tormota）是已知的第一种能够使用超声波进行交流的非哺乳动物脊椎动物。在该物种中，雌性个体大约是雄性的四倍，雌性的生长速度明显高于雄性。到目前为止，尚未报道雄性和雌性青蛙肌肉生长发育差异的分子机制。在这里，我们整合了 mRNA 和 miRNA 表达谱，以揭示 2 岁青蛙后肢肌肉的生长差异。在 569 个差异表达基因（DEGs）中，有 69 个与肌肉生长和再生有关。51 个在雌性中上调的基因可能参与促进肌肉生长和再生，而 18 个在雄性中上调的基因可能导致肌肉生长抑制和快肌纤维收缩。244 个 DEGs 富集在 mTOR 和其他蛋白质合成信号通路以及蛋白质降解通路，包括溶酶体蛋白酶、钙蛋白酶、半胱天冬酶和泛素-蛋白酶体系统途径。这可能解释了为什么雌性肌肉比雄性生长得更快。基于参与糖酵解和氧化代谢的基因表达差异，我们推测与雄性肌肉相比，雌性肌肉中的慢肌纤维比例更高，快肌纤维比例更低。此外，鉴定出 767 个 miRNA，包括 217 个新 miRNA，预测到 6248 个 miRNA 负调控的 mRNA。miRNA 靶基因富集在与肌肉生长、蛋白质合成和降解相关的途径中。因此，除了鉴定出的 mRNA 差异表达外，miRNA 可能在中华蟾蜍雌雄后肢肌肉生长的差异调节中发挥其他重要作用。
