Generation of fertile offspring from Kitw/Kitwv mice through differentiation of gene corrected nuclear transfer embryonic stem cells

Genetic mutations could cause sperm deficiency, leading to male infertility. Without functional gametes in the testes, patients cannot produce progeny even with assisted reproduction technologies such as in vitro fertilization. It has been a major challenge to restore the fertility of gamete-deficient patients due to genetic mutations. In this study, using a KitW/Kitwv mouse model, we investigated the feasibility of generating functional sperms from gamete-de- ficient mice by combining the reprogramming and gene correcting technologies. We derived embryonic stem cells from cloned embryos （ntESCs） that were created by nuclear transfer of KitW/Kitwv somatic cells. Then we generated gene-corrected ntESCs using TALEN-mediated gene editing. The repaired ntESCs could further differentiate into primordial germ cell-like cells （PGCLCs） in vitro. RFP-labeled PGCLCs from the repaired ntESCs could produce functional sperms in mouse testes. In addition, by co-transplantation with EGFP-labeled testis somatic cells into the testes where spermatogenesis has been chemically damaged or by transplantation into Kitw/Kitwv infertile testes, non-labeled PGCLCs could also produce haploid gametes, supporting full-term mouse development. Our study explores a new path to rescue male infertility caused by genetic mutations.