MicroRNA-184 downregulates nuclear receptor corepressor 2 in mouse spermatogenesis

Background: There have been increasing attentions on the role of small RNAs, especially microRNAs in post-transcriptional gene regulation during spermatogenesis. MicroRNA-184 (miR-184) has been shown to be mainly expressed in the testis and brain, and that its expression levels are by far the highest in the testis. However, the role of miR-184 in mammalian spermatogenesis remains unclear. Results: In this study, we demonstrated that miR-184 levels were increased during mouse postnatal testis development. Specifically, miR-184 expression was restricted to the germ cells from spermatogonia to round spermatids. Overexpression of miR-184 promoted the proliferation of a germ cell line, GC-1spg. Moreover, miR-184 downregulated nuclear receptor corepressor 2 (Ncor2) by targeting its 3' untranslated region through inhibiting NCOR2 protein translation. Conclusions: MiR-184 may be involved in the post-transcription regulation of mRNAs such as Ncor2 in mammalian spermatogenesis.