SPATA16

SPATA16, or Spermatogenesis-associated 16, is a protein-coding gene in humans that plays a role in the later stages of spermatogenesis. Its expression is enriched in testicular tissue, particularly in developing germ cells, and it is conserved across vertebrates, suggesting an evolutionarily important function in male fertility.

In spermiogenesis, SPATA16 is linked to the formation of the acrosome, a proacrosomal vesicle-derived structure that caps the sperm nucleus and is essential for fertilization. The protein is thought to localize to the Golgi apparatus and associated vesicles involved in acrosome biogenesis, where it may participate in vesicle trafficking and proper assembly of the acrosomal cap. This positioning supports a role for SPATA16 in ensuring correct sperm head morphology and maturation.

Clinical significance of SPATA16 arises from studies in humans and model organisms that connect its dysfunction to impaired spermatogenesis and male infertility. Pathogenic variants and altered expression of SPATA16 have been reported in men with abnormal sperm morphology and reduced fertility, including cases with acrosome-related defects. However, the evidence base consists of limited studies, and causality remains to be firmly established in larger cohorts. Animal models, such as mice with disrupted SPATA16 function, demonstrate defects in acrosome formation and reduced fertility, reinforcing its proposed involvement in spermiogenesis.

Overall, SPATA16 is considered a candidate gene in the study of male infertility and acrosome biogenesis, with further research needed to clarify its spectrum of variants, penetrance, and mechanisms across species.