Comparative analysis on mRNA expression level and methylation status of DAZL gene between cattle-yaks and their parents

Abstract

The autosomal gene Deleted in Azoospermia Like ( DAZL) is essential for spermatogenesis. The absence of DAZL gene will lead to meiotic arrest, spermatogenetic failure and male infertility, and so it was usually considered as a candidate gene for male infertility in cattle-yaks. To study the regulatory mechanism of DAZL expression in cattle-yaks, DAZL mRNA expression and DAZL gene methylation patterns in testes of cattle, yaks and cattle-yaks were examined using real-time PCR and bisulfite sequencing. The results showed that DAZL mRNA expression in testes of cattle-yaks was lower than that in cattle and yak (about 1/2–1/3 of cattle and yak). The methylation level of DAZL in cattle-yaks (85.6%) was significantly higher than that in cattle (69.8%) and yaks (71.4%) ( P < 0.01). The methylation and mRNA expression level of DAZL was significantly negatively correlated in the testes of cattle-yaks and their parents ( P < 0.01). We propose that the methylation of DAZL gene plays an important role in DAZL transcriptional regulation and maybe have a severe effect on spermatogenesis and male sterility in cattle-yaks.