Abstract

Long non-coding RNAs (lncRNAs) have been reported to regulate the spermatogenesis. In this study, we aim to characterize the expression pattern and roles of lncRNA schlafen 5, opposite strand (Slfn5os) in the testis of adult mouse. The expression of lncRNA Slfn5os and Slfn5 in different tissues was examined by Reverse-Transcription Polymerase Chain Reaction (RT-PCR). The localization of lncRNA Slfn5os and Slfn5 was determined by Fluorescence In situ Hybridization (FISH). TM3 Leydig cell line was used as a cellular model to study the function of Slfn5os. The survival of TM3 cells upon Slfn5os knockdown or overexpression was assessed by Cell Count Kit-8 (CCK-8) viability assay and flow cytometry. The secretion of testosterone by TM3 cells was detected by Enzyme-Linked Immuno Sorbent Assay (ELISA). We found that Schlafen family member 5 (Slfn5) was widely expressed in all the tissues examined, while lncRNA Slfn5os was exclusively expressed in the testis. FISH staining revealed a Leydig cell-specific expression of Slfn5os. The expression level of Slfn5os negatively regulates the mRNA level of Slfn5. In addition, forced expression of Slfn5os impaired the survival and testosterone production in TM3 cells, while Slfn5os silencing showed the opposite effects. The reduced testosterone production upon Slfn5os overexpression was associated with the down-regulation of steroidogenic genes. We conclude that Slfn5os is a testis-enriched lncRNA in mouse testis, which regulates the survival and testosterone production in Leydig cells.