The deubiquitinating gene Usp29 is dispensable for fertility in male mice.

The balanced actions between ubiquitination and deubiquitination precisely control the levels of various proteins vital for spermatogenesis. Ubiquitin-specific processing proteases (USPs) are the largest family of deubiquitinatingenzymes(DUBs), containing more than 50 members. So far, the functions of only a few USPs in male fertility have been studied, the roles of the majority are yet unknown. The present study aimed to explore the function of Usp29 (ubiquitin-specific protease 29) in male fertility. We found that Usp29 showed predominant expression in mouse testis, and its mRNA expression started to increase at 14 days postpartum (dpp), with a peak at 28 and 35 dpp. Using CRISPR/Cas9 technology, we generated Usp29 knockout mice (Usp29-/-). Usp29-/- mice exhibited no overt developmental anomalies. Further examination revealed that Usp29-/- mice had normal fertility and showed no detectable difference in the testis/body weight ratio, testicular and epididymal histology as well as epididymal sperm count from the wild-type littermates. Moreover, Usp29 is not a pseudogene in mice. Taken together, our study first reported that though Usp29 is predominantly expressed in the testis, it is not essential for male fertility in mice.