4. Review: Role of microRNAs during spermatogenesis in mammals
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Abstract
The spermatogenesis in mammals comprises three stages: the mitotic proliferation of spermatogonia, meiosis of spermatocyte, which produces haploid spermatids, and spermiogenesis which leads spermatozoa into the tubule lumen. Each step of spermatogenesis is controlled by a number of factors including microRNAs (miRNAs) for the regulation of gene expression, these single-stranded non-coding small RNAs molecules contains about 19~25 nucleotides. Since first miRNAs (Let-7 and lin-4) were discovered in Caenorhabditis elegance, thousands of miRNA have been identified from different species in the past 23 years. It has been reported that the miRNAs function as guide molecules in post-transcriptional regulation by base pairing with target messenger RNA (mRNA) and lead to cleavage or translational repression. Recently, several pieces of evidence suggested that the miRNAs are closely related to the spermatogenesis by the analyzing mRNA changes in testicular tissue from different animal species. The present review has summarized the recent progress on the role of miRNAs during spermatogenesis which may contribute to understate the spermatogenic arrest in mammals.
Keywords: Gene expression; Infertility; MicroRNAs; Spermatogenesis