Abstract: microRNA, a class of noncoding RNA of approximately 19-25 nucleotides, which can regulate gene expression by binding to the region of 3’ UTR of the target mRNAs to degrade or suppress target genes, is a post-transcriptional regulation. At present, thousands of microRNAs have been identified successfully. It is demonstrated that microRNA play an important role in cellular proliferation and apoptosis, self-renewal, stem cell differentiation, as well as in the development of germ cell and embryo, the regulation of hormone secretion.

Key words: microRNA, Gene expression regulation, Reproduction, Embryonic development