[Progress on meiotic gene expression and epigenetic regulation of male sterility in Dzo cattle]

Interspecific hybrid male sterility is a common occurrence in nature and plays an important role in species reproductive isolation. Dzo (cattle-yak), the offspring of interspecific cross between domestic yak (Bos grunniens) and cattle (Bos taurus), is a unique animal model for investigating interspecific hybrid male sterility. Dzo females are completely fertile while the males are sterile. In recent years, molecular studies have demonstrated that the expressions of genes were dysregulated during meiosis in Dzo testis, as compared to those in cattle or yak. Other studies have revealed that epigenetic factors/events, such as DNA methylation, histone modification and non-coding RNA, are also involved in spermatogenesis. This review summarizes the dysregulation of gene expression, DNA methylation, microRNA (miRNA), PIWI-interacting RNA (piRNA), long non-coding RNA (lncRNA), and histone methylation modification during meiosis in Dzo testis. These results highlighted the potential roles of genetic and epigenetic regulations of meiosis in Dzo testis, thereby providing a more detailed understanding on the molecular mechanisms of interspecific hybrid male sterility.