Restore natural fertility of Kitw/Kitwv mouse with nonobstructive azoospermia through gene editing on SSCs mediated by CRISPR-Cas9.

BACKGROUND

Male infertility is a serious social problem in modern society. Nonobstructive azoospermia (NOA) caused by germ cell gene defects is an important reason for male infertility, but effective clinical treatment for this disease has not been established.

METHODS

We choose Kitw/Kitwv mouse as a research model and try to develop a new treatment strategy and "cure" its infertility. Mutant spermatogonial stem cells (SSCs) were isolated from one single unilateral testis of a 14-day-old Kitw/Kitwv mouse and propagated in vitro. The C to T point mutation on Kitwv site of these SSCs was corrected through CRISPR-Cas9-mediated homology-directed repair (HDR) in vitro. Then, the repaired SSCs were screened out, proliferated, and transplanted into the remaining testis, and complete spermatogenesis was established in the recipient testis.

RESULTS

Healthy offsprings with wild type Kit gene or Kitw mutation were obtained through natural mating 4 months after SSC transplantation.

CONCLUSION

In this study, we established an effective new treatment strategy for NOA caused by germ cell gene defects through a combination of SSC isolation, CRISPR-Cas9-mediated gene editing, and SSC transplantation, which brought hope for these NOA patients to restore their natural fertility.