Hsp60 expression and localization in different tissues and testis development of male cattle (cattle-yak and yak)

Background: Heat shock protein 60 (Hsp60) play important roles in protecting testicular development and production of sperms. This study was conducted to investigate Hsp60 gene expression and localization in testicular development to ascertain its influence on infertility and in different tissues of the male cattle-yak and yak. A total of 54 cattle (24 cattle-yak and 30 yak) were examined. Materials and methods: Hsp60 mRNA of cattle-yak was cloned first and amino acid variations were found leading to differences at protein spatial structure compare with the yak. Real-time quantitative PCR (RT-qPCR) analysis revealed that Hsp60 mRNAs expression were different in cattle-yak and yak. Results: The results showed disparity in Hsp60 expression among different tissues and in different developmental stages of the testis. High Hsp60 expression was observed in juvenile and adult testicles. Moreover, Hsp60 expression in cattle-yak was significantly higher than yak (p < 0.01). The location of Hsp60 in tissue and testis was detected by immunohistochemistry (IHC) and immunofluorescence (IF). The results demonstrated that Hsp60 proteins located in epithelial cells, spermatocytes, sperm cells and mesenchymal cells. Conclusions: The Hsp60 proteins are expressed in different tissues, and the highest expression level was observed in the testis of the cattle-yak, which suggests that infertility of cattle-yak have some correlation with up-regulation of Hsp60.