Abstract
BACKGROUND: More than 1000 genes have been identified as predominantly expressed in the human testis. Advances in gene editing technologies have enabled the rapid and efficient generation of genetically engineered mice. This approach facilitates the screening of genes essential for spermatogenesis by analyzing knockout mouse models. OBJECTIVES: This study aimed to elucidate the essential genes in male reproductive function by generating knockout mouse models. MATERIALS AND METHODS: We selected 11 target genes that may have potential roles in the male reproductive system based on a public database. Knockout mouse lines of these target genes were generated using the CRISPR/Cas9 system to elucidate their functions in male reproduction. Also, we conducted natural mating tests to elucidate fecundity and analyzed the phenotype of the knockout males. RESULTS: Natural mating tests revealed that all 11 gene-deficient mouse lines maintained normal male fertility. The phenotypic analysis, including testis appearance and weight, histology of testis and epididymis, and sperm motility and morphology, showed no apparent abnormalities. DISCUSSION AND CONCLUSION: These results suggest that each gene is not essential for male reproductive function.