Normal spermatogenesis and fertility in Spmip8 deficiency male mice

Spmip8, also known as Tepp, is a protein-coding gene which highly conserved in the mammals. Although SPMIP8 has been reported to be highly expressed in the testis, the function of SPMIP8 in spermatogenesis and male fertility remain unknown. In this study, we used CRISPR/cas9-mediated genome editing system to generate Spmip8-deficient mice. The phenotype of Spmip8 knockout (KO) male mice was performed by fertility tests, histology, and immunofluorescence. SPMIP8 is localization to the flagella of elongating spermatids in testis. Spmip8 KO male mice exhibited normal fertility. No significant differences were found in sperm count, motility, morphology and kinematic parameters between WT and Spmip8 KO mice. Furthermore, no detectable defects in spermatogenesis were found in KO mice. The transcription level of several Spmip genes (Spmip1, Spmip2, Spmip3, Spmip7 and Spmip11) was elevated in the testes of Spmip8 knockout mice, suggesting that Spmip8 gene in male fertility could be compensated by other Spmip family members. Overall, the findings of this study suggest that Spmip8 is not an essential gene for male fertility in mice. Our study helps researchers avoid duplication and repetitive work and explore genes that are integral to spermatogenesis and male fertility.