Wang Xingdong, Pei Jie, Guo Shaoke, Cao Mengli, Bao Pengjia, Xiong Lin, Wu Xiaoyun, Chu Min, Liang Chunnian, Yan Ping, Guo Xian
Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Front Cell Dev Biol. 2021 Nov 11;9:755670. doi: 10.3389/fcell.2021.755670. eCollection 2021.
The potential regulatory role of N-methyladenosine (mA), the most prominent mRNA modification in eukaryotes, has recently been identified in mammals, plants, and yeast. However, whether and how mA methylation is involved in sexual maturation in mammals remains largely unexplored. In this study, testicular tissue was obtained from yaks before and after sexual maturation, and mA maps were generated via preliminary experiments and methylated RNA immunoprecipitation sequencing. Only spermatogonial cells and a few primary spermatocytes were observed in the testicular tissue of yaks before sexual maturation, while spermatogenic cells at different stages of maturity could observed after sexual maturation. Experiments examining the expression of methylation-related enzymes and overall methylation levels showed that the methylation levels in yak testes increased after sexual maturation. Overall, 1,438 methylation peaks were differentially expressed before and after sexual maturation; 1,226 showed significant up-regulation and 212 showed significant down-regulation after sexual maturation. Annotation analysis showed that the differential methylation peaks were most commonly concentrated in the exon region, followed by the 3'UTR and finally the 5'UTR region. KEGG pathway analysis demonstrated that homologous recombination, the Notch signaling pathway, growth hormone synthesis, and other signaling pathways may be involved in testicular development and maturation in yaks. Levels of most mA modifications were positively correlated with mRNA abundance, suggesting that mA plays a regulatory role in mammalian sexual maturation. To our knowledge, this is the first report of an mA transcriptional map of the yak testes, and our study lays the foundation for elucidating the function of mA in the development of yak testes.
N-甲基腺苷（mA）是真核生物中最显著的mRNA修饰，其潜在的调控作用最近已在哺乳动物、植物和酵母中得到确认。然而，mA甲基化是否以及如何参与哺乳动物的性成熟过程，在很大程度上仍未得到探索。在本研究中，采集了牦牛性成熟前后的睾丸组织，并通过初步实验和甲基化RNA免疫沉淀测序生成了mA图谱。性成熟前牦牛睾丸组织中仅观察到精原细胞和少数初级精母细胞，而性成熟后可观察到不同成熟阶段的生精细胞。对甲基化相关酶表达和总体甲基化水平的实验表明，牦牛睾丸中的甲基化水平在性成熟后有所增加。总体而言，1438个甲基化峰在性成熟前后差异表达；性成熟后，1226个显著上调，212个显著下调。注释分析表明，差异甲基化峰最常见于外显子区域，其次是3'UTR，最后是5'UTR区域。KEGG通路分析表明，同源重组、Notch信号通路、生长激素合成及其他信号通路可能参与牦牛睾丸的发育和成熟。大多数mA修饰水平与mRNA丰度呈正相关，表明mA在哺乳动物性成熟中发挥调控作用。据我们所知，这是关于牦牛睾丸mA转录图谱的首次报道，我们的研究为阐明mA在牦牛睾丸发育中的功能奠定了基础。
