Institute of Animal Sciences, Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, Colorado State University, 1351 Rampart Rd, Fort Collins, CO 80523, USA.
Int J Mol Sci. 2020 Jan 16;21(2):585. doi: 10.3390/ijms21020585.
The genetic codes inscribed during two key developmental processes, namely gametogenesis and embryogenesis, are believed to determine subsequent development and survival of adult life. Once the embryo is formed, its further development mainly depends on its intrinsic characteristics, maternal environment (the endometrial receptivity), and the embryo-maternal interactions established during each phase of development. These developmental processes are under strict genetic regulation that could be manifested temporally and spatially depending on the physiological and developmental status of the cell. MicroRNAs (miRNAs), one of the small non-coding classes of RNAs, approximately 19-22 nucleotides in length, are one of the candidates for post-transcriptional developmental regulators. These tiny non-coding RNAs are expressed in ovarian tissue, granulosa cells, testis, oocytes, follicular fluid, and embryos and are implicated in diverse biological processes such as cell-to-cell communication. Moreover, accumulated evidences have also highlighted that miRNAs can be released into the extracellular environment through different mechanisms facilitating intercellular communication. Therefore, understanding miRNAs mediated regulatory mechanisms during gametogenesis and embryogenesis provides further insights about the molecular mechanisms underlying oocyte/sperm formation, early embryo development, and implantation. Thus, this review highlights the role of miRNAs in mammalian gametogenesis and embryogenesis and summarizes recent findings about miRNA-mediated post-transcriptional regulatory mechanisms occurring during early mammalian development.
在两个关键的发育过程中，即配子发生和胚胎发生期间所记录的遗传密码，被认为决定了成年后的后续发育和生存。一旦胚胎形成，其进一步的发育主要取决于其内在特性、母体环境（子宫内膜容受性）以及在每个发育阶段建立的胚胎-母体相互作用。这些发育过程受到严格的遗传调控，根据细胞的生理和发育状态在时间和空间上表现出来。微小 RNA（miRNA）是长度约为 19-22 个核苷酸的小非编码 RNA 之一，是转录后发育调节剂的候选者之一。这些微小的非编码 RNA 在卵巢组织、颗粒细胞、睾丸、卵母细胞、卵泡液和胚胎中表达，并参与多种生物学过程，如细胞间通讯。此外，越来越多的证据也强调了 miRNA 可以通过不同的机制释放到细胞外环境中，从而促进细胞间的通讯。因此，了解 miRNA 在配子发生和胚胎发生过程中的调节机制，为卵母细胞/精子形成、早期胚胎发育和着床的分子机制提供了进一步的认识。因此，本综述强调了 miRNA 在哺乳动物配子发生和胚胎发生中的作用，并总结了最近关于早期哺乳动物发育过程中 miRNA 介导的转录后调节机制的发现。
