Comparative RNA-Seq Analysis of Differentially Expressed Genes in the Sertoli cells of Yak and Cattle-yak

Abstract Background To study the problem of male sterility of cattle-yak and improve the yak crossbreeding, this study obtained the testicular Sertoli cells of yak and cattle-yak and compared the differences in transcriptome levels between the two bovine species. The testicular tissues of 3 healthy male cattle-yaks and 3 F 1 generation male yaks were collected at the age of 24 months. The Sertoli cells were isolated after enzymatic digestion, differential adhesion and starvation treatment. DATA-4 and SOX9 immunofluorescence staining were used to identify the cell type. Sertoli cells were subjected to transcriptome sequencing, GO analysis, KEGG analysis and differentially expressed gene validation. Results The study successfully isolated and purified Sertoli cells of yak and cattle-yak. The transcriptome sequencing data were compared, analyzed and annotated. Compared to yak Sertoli cells, 6592 differentially expressed genes were obtained, 3007 genes were upregulated and 3585 genes were downregulated in cattle-yak Sertoli cells. GO analysis showed that upregulated genes were mainly involved in translation, peptide biosynthetic process, amide biosynthetic process, peptide metabolic process, ribosome, cytoplasmic part, structural constituent of ribosome, structural molecule activity, endomembrane system, protein kinase activity, phosphotransferase activity, etc. The downregulated genes were mainly involved in protein phosphorylation, phosphorylation, endomembrane system, protein kinase activity, phosphotransferase activity, etc. KEGG analysis compared differential genes to 316 pathways, of which 8 pathways were significantly enriched. The upregulated pathways were significantly enriched in cattle-yak Sertoli cells, including ribosome, thermogenesis, oxidative phosphorylation, etc. The downregulated pathways were significantly enriched in adherens junction, mTOR signaling pathway, AMPK signaling pathway, FoxO signaling pathway, focal adhesion, etc. Conclusions Compared with yak Sertoli cells, the expression of genes related to protein activation, cell function and membranous organelle composition in cattle-yak Sertoli cells was abnormal. The defects of cattle-yak Sertoli cells cannot provide a suitable environment for spermatogenesis which may be one of the reasons for male cattle-yak sterility.