Localization and functional analysis of miR-92a-3p regulating Ino80d in mouse testis

Testicular development and spermatogenesis in mice involve complex and dynamic gene regulation and chromatin remodelling. In this study, Real-time fluorescence quantitative PCR (RT-qPCR), Western Blot (WB), Immunofluorescence (IF), transfection and other techniques were used to analyse the expression of Ino80d mRNA and its encoded proteins in mouse testicular tissue and mouse spermatogonial cells, and to further analyse the possible target-regulatory relationship and function of miR-92a-3p and Ino80d. We found that Ino80d mRNA and protein expression was up-regulated in adult mouse testis tissue relative to juvenile mouse testis tissue, whereas miR-92a-3p expression was down-regulated in adult mouse testis tissue. Immunofluorescence results showed that the Ino80d protein was mainly localized in the nucleus of male germ cells. Ino80d protein expression is higher in spermatogonia, spermatid and lower in primary spermatocytes, secondary spermatocytes and sperm. There is a decreasing trend in development from spermatogonia to secondary spermatocytes. The transfection results showed that the expression levels of Ino80d mRNA and protein were down-regulated after overexpression of miR-92a-3p in mouse spermatogonia. Increased miR-92a-3p may be a key factor in inhibiting the expression of Ino80d mRNA and proteins in the miR-92a-3p mimics group of mouse spermatogonial cells, whereas differential expression may be a result of the negative regulation of miR-92a-3p, which regulates testicular development and spermatogenesis in mice.