STOML2 is not essential for spermatogenesis and male fertility in mice

Stomatin-like protein 2 (STOML2) localizes to the mitochondrial inner membrane and regulates mitochondrial biogenesis and function. STOML2's role in spermatogenesis is unknown but given that proper mitochondrial function is required proper male germ cell development and function, we elected to study STOML2's role in the testis. The expression pattern of STOML2 in mouse testes was investigated by RT-PCR and Western blot. Stoml2 RNA was highly expressed in mouse testes and STOML2 protein was localized in the cytoplasm of testicular germ cells. A Stoml2 knockout (KO) mouse model was generated and phenotypes were assessed. Stoml2 KO male mice displayed normal morphology and weight of testes and epididymides, as well as normal fertility. The number and morphology of sperm from Stoml2 KO mice were not changed significantly. Histological analyses of KO testes revealed normal spermatogenesis, and the number of testicular germ cells and Sertoli cells were not significantly altered. Taken together, our results demonstrate that STOML2 is not required for spermatogenesis and male fertility in mice.