The role of Musashi protein in spermatogenesis and male infertility

Background: Inactivation of transcription occurs during two phases of spermatogenesis. First, in spermatocytes entering the primary meiosis and the second in round and elongating spermatids. These stages of inactivated transcription demand extensive regulation of translation. Therefore, presence of the control on gene expression during spermatogenesis seems essential. In the cases that post-transcription controlling mechanisms show an abnormal function, spermatogenesis will be impaired. RNA-binding proteins have an important effect in this phenomenon. One group of these proteins is Musashi family that plays a critical role during spermatogenesis and this study aimed to examine the role of this protein family during spermatogenesis. Materials and Methods: This study was a review article and the selection of the papers was done using Google scholar, PubMed and Scopus databases and special key words. Then, all related English-language papers between 1994 and 2018 were considered. Results: Several studies showed that Musashi 1 had an important role in the early stage of spermatogenesis in which spermatogonia and gonocytes proliferate, while Musashi 2 had a central role during the late stage of spermatogenesis for differentiation of spermatocytes and spermatids. Conclusion: Musashi proteins have a critical role during spermatogenesis. Severe pathological defects were detected in transgenic models with knockdown or knockout Musashi, including sperm abnormal morphology, DNA fragmentation and low fertilization potential.