Abstract: Objective To explore the physiological function of gene for cell devision cycle associated 2 (Cdca2), a highly expressed testis gene, in spermatogenesis and fertility in mice. Methods The expression of Cdca2 in different tissues of mice was detected by Q-PCR and Western blot; Using CRISPR/Cas9 gene editing technology and Cre-loxP mediated recombination system, a mouse strain with Cdca2 tissue specific knockout was constructed; By hematoxylin-eosin(HE) staining and morphological analysis, the effect of CDCA2 deletion on spermatogenic cell morphology at different stages of spermatogenesis was studied; The effects of CDCA2 deletion on sperm motility and motility parameters were detected by an automatic sperm detection and analysis system; The effect of CDCA2 deletion on the fertility of male mice was examined by fertility test. Results Cdca2 was a highly expressed gene in testis; Cdca2 germ cell specific knockout mice were successfully obtained by CRISPR/Cas9 technology and reproductive system; CDCA2 deletion in mice had no statistically significant effect on spermatogenic cells, sperm motility parameters and male fertility at all stages of spermatogenesis. Conclusions Cdca2 is probably not necessary for spermatogenesis and male fertility maintenance in mice.

Key words: cell division cycle associated 2(CDCA2), RNA binding protein, germ cell, fertility, spermatogenesis