X-ray repair cross-complementing group 1 (Xrcc1), a key DNA repair gene, plays a vital role in maintaining genomic stability and is highly expressed in the early stages of spermatogenesis, but the exact functions remain elusive. Here we generated primordial germ cell-specific Xrcc1 knockout (cXrcc1-/-) mice to elucidate the effects of Xrcc1 on spermatogenesis. We demonstrated that Xrcc1 deficiency results in infertility in male mice due to impaired spermatogenesis. We found that cXrcc1-/- mice exhibited smaller size of testes as well as lower sperm concentration and motility than the wild-type mice. Mechanistically, we demonstrated that Xrcc1 deficiency in primordial germ cells induced elevated levels of reactive oxygen species, mitochondria dysfunction, apoptosis, and loss of stemness of spermatogonial stem cells (SSCs) in testes. In Xrcc1-deficienct SSCs, elevated oxidative stress and mitochondrial dysfunction could be partially reversed by treatment with the antioxidant N-acetylcysteine (NAC), whereas NAC treatment did not restore the fertility or ameliorate the apoptosis caused by loss of Xrcc1. Overall, our findings provided new insights into understanding the crucial role of Xrcc1 during spermatogenesis.-Xu, C., Xu, J., Ji, G., Liu, Q., Shao, W., Chen, Y., Gu, J., Weng, Z., Zhang, X., Wang, Y., Gu, A. Deficiency of X-ray repair cross-complementing group 1 in primordial germ cells contributes to male infertility.
Keywords: spermatogenesis; mitochondrial dysfunction; oxidative stress.