GLUL deficiency causes sperm acrosome defects and male infertility via influencing redox balance in mice.

Glutamate-ammonia ligase (GLUL) catalyzes the syntheses of glutamine, as the antioxidant that has been shown to influence sperm quality in mammals. Research on the precise functions of the GLUL gene during spermatogenesis has been constrained by the structural complexity of the testis. In this study, we established a mouse model with postnatal, germ cell-specific deletion of GLUL. Conditional knockout (cKO) of GLUL led to reduced male fertility. Epididymal sperm from cKO mice exhibited acrosomal malformation, diminished acrosin activity, and redox imbalance. Moreover, GLUL deficiency was found to alter protein levels of Spam1 and Tssk3 in epididymal sperm. These functional deficits could be partially rescued by intraperitoneal glutathione (GSH) administration or by intracytoplasmic sperm injection (ICSI). Collectively, our results demonstrate that GLUL in germ cells is essential for combating oxidative stress during spermatogenesis in mice. These findings enhance the understanding of GLUL's role in male germ cell development and propose GSH supplementation as a potential therapeutic strategy for conditions associated with low acrosin activity.