Comparative analysis of the testis tissue transcriptome of 4-year-old yak and cattle-yak

RNA sequence analysis identified a total of 8473 differentially expressed genes (DEGs) (3580 up-regulated, 4893 down-regulated), and GO annotation and KEGG enrichment of differential genes found that DEGS were mostly related to spermatogenesis and apoptosis. Among them, Spermatogonia stem cell (SSCs) marker genes (ITGA5, Gfra1, CD9, SOHLH1, SALL4, ID4 and FOXO1) were significantly up-regulated, differentiation spermatogenic cell marker genes (KIT, UCHL1, Ccna1, TNP1 and TXNDC2) were significantly down-regulated, and genes involved in apoptosis (Fas, CTSK, CTSB, CTSC, CTSO, caspase 3, caspase6, and caspase) were significantly up-regulated. Furthermore, the AS events in cattle-yak are significantly lower than in yak, we speculate that lack of mRNA and protein subtypes may lead to spermatogenic arrest in yak testicle. Overall design: RNA-seq of yak and cattle-yak testis tissue.