Expression and localization of HSPA2 and SPATA6 in testis of Pengbo semi-fine wool sheep

Heat shock protein A2 (HSPA2) is an important member of the HSP70 family, promoting the proliferation of testicular support cells. Spermatogene-related gene 6 (SPATA6) can regulate the microfilament transport system of myosin synthesis and affect the formation of the sperm cytoskeleton, both of which play important roles in the reproductive process of male mammals. This study investigated the regulation mechanisms of heat shock protein A2 (HSPA2) and spermatogenesis-related gene 6 (SPATA6) in the reproductive process of male animals to provide a scientific basis for the breeding of Pengbo semi-fine wool sheep. Pengbo semi-fine wool sheep of different ages (3 months, 12 months, and 3 years) were taken as the research object. Real-time quantitative PCR (qRT-PCR), western blot, and immunohistochemical staining were used to detect the expression and distribution patterns of HSPA2 and SPATA6 in the testicular tissues of Pengbo semi-fine wool sheep of different ages from transcription and translation levels and to analyze the biological functions of HSPA2 and SPATA6 in the testicular development and spermatogenesis of Pengbo semi-fine wool sheep. Results showed that the relative expression of HSPA2 mRNA and protein in the testis of Pengbo semi-fine wool sheep at the age of 12 months and 3 years was significantly higher than that at the age of 3 months (P < 0.01); moreover, they tended to be stable after sexual maturity. The relative expression of SPATA6 mRNA and protein at 12 months old was significantly higher than that at 3 months old (P < 0.01) and significantly higher than that at 3 years old (P < 0.05). HSPA2 and SPATA6 proteins were distributed in sertoli cells and interstitial cells of the testicular tissue of Pengbo semi-fine wool sheep at different ages. We speculate that HSPA2 and SPATA6 play an important role in regulating spermatogenesis and promoting sperm maturation.