Abstract: Objective To investigate whether QKI protein plays an important role in the process of spermatogenesis. Constructing GC1-spg cell line which knocked out QKI gene by the technology of CRISPR / Cas9 ，and detecting its effect on the proliferation and differentiation of QKI protein in vitro. Methods The plasmid PX330 was used to construct QKI gene knockout recombinant plasmid, then was transfected it to GC1-spg wild-type cells and was selected it by puromycin, and GC1-spg knock-QKI gene cell lines were identified by Western Blot and gene sequencing; The wild-type and knockout cell lines were cultured normally, then detected the growth curve by cell counting kit (CCK8) , and using quantitative PCR to get the changes of meiotic-related gene differentiation. Results In this study, QKI gene knockout GC1-spg cell line was successfully constructed. Compared with the control group, the growth of QKI knockout cell line was significantly decreased (*P < 0.05), and the expression of meiosis related molecular marker gene was significantly decreased (*P < 0.05). Conclusions QKI proteins can affect reproductive spermatogenesis by acting on proliferation and differentiation.

Key words: CRISPR/CAS9, GC1-spg, QKI, Spermatogenesis