Study of microRNA Expression Profile in Different Regions of Ram Epididymis

The regional expression of epididymal genes provides a guarantee for sperm maturation. As a class of endogenous non-coding small RNAs, microRNAs (miRNAs) play an important role in spermatogenesis, maturation and fertilization. Currently, the regulatory role of miRNA in the epididymis is poorly understood. Here, transcriptome sequencing was used to analyse miRNA expression profiles in three regions of the epididymis of rams, including caput, corpus and cauda. The results showed that there were 13 known miRNAs between the caput and corpus controls, 29 between the caput and cauda and 22 differences between the corpus and cauda. Based on the analysis of miRNA target genes by GO and KEGG, a negative regulation network of miRNA-mRNA was constructed in which let-7, miR-541-5p, miR-133b and miR-150 may play an important regulatory role in the maturation regulation of ram epididymal sperm. This research provides a reference for studying the regulation mechanism of sperm maturation in male epididymis and improving semen quality and male reproductive performance.