부산대학교 도서관

Simple Summary: Abnormal expression of the HSF2 gene was shown to be associated with male sterility. Here, we found that HSF2 was highly expressed in the testes of the cattle-yak, especially in adult cattle-yak. However, the expression of HSF2 was significantly lower in the cattle-yak compared to cattle and yak. In addition, the methylation level of the promoter region was significantly higher in cattle-yak compared to yak. We therefore suggest that male cattle-yak sterility may be associated with methylation of the HSF2 gene in testes tissues. This study provides theoretical support for further understanding of male cattle-yak sterility. Aberrant expression of the heat shock proteins and factors was revealed to be closely associated with male reproduction. Heat shock factor 2 (HSF2) is a transcription factor that is involved in the regulation of diverse developmental pathways. However, the role and the corresponding molecular mechanism of HSF2 in male cattle-yak sterility are still poorly understood. Therefore, the aim of this study was to obtain the sequence and the biological information of the cattle-yak HSF2 gene and to investigate the spatiotemporal expression profiles of the locus during the development of cattle-yak testes. Additionally, the differential expression was analyzed between the cattle-yak and the yak, and the methylation of corresponding promoter regions was compared. Our results showed an additional 54 bp fragment and a missense mutation (lysine to glutamic acid) were presented in the cattle-yak HSF2 gene, which correlated with enriched expression in testicular tissue. In addition, the expression of the HSF2 gene showed dynamic changes during the growth of the testes, reaching a peak in adulthood. The IHC indicated that HSF2 protein was primarily located in spermatocytes (PS), spermatogonia (SP), and Sertoli cells (SC) in cattle-yak testes, compared with the corresponding cells of cattle and the yak. Furthermore, bisulfite-sequencing PCR (BSP) revealed that the methylated CpG sites in the promoter region of the cattle-yak HSF2 were more numerous than in the yak counterpart, which suggests hypermethylation of this region in the cattle-yak. Taken together, the low expression abundance and hypermethylation of HSF2 may underpin the obstruction of spermatogenesis, which leads to male cattle-yak infertility. Our study provided a basic guideline for the HSF2 gene in male reproduction and a new insight into the mechanisms of male cattle-yak sterility. [ABSTRACT FROM AUTHOR]