Sirt6 is required for spermatogenesis in mice

Area of Science:

• Molecular Biology
• Reproductive Biology
• Genetics

Background:

• SIRT6 (Sirtuin 6) is a nuclear protein involved in DNA repair, metabolism, inflammation, aging, and cancer.
• The function of SIRT6 in male reproductive processes, specifically spermatogenesis, remains largely unexplored.

Purpose of the Study:

• To investigate the role of SIRT6 in the regulation of spermatogenesis and male fertility.
• To determine if SIRT6's deacetylase activity is essential for successful sperm development.

Main Methods:

• Generation of Sirt6-deficient mice on a mixed C57BL6/ICR background.
• Assessment of spermatogenesis progression, fertility, and germ cell apoptosis in Sirt6 mutant mice.
• Evaluation of SIRT6's deacetylase activity on specific histone marks (H3K9ac, H3K18ac, H3K56ac).

Main Results:

• Sirt6-deficient mice exhibited arrested spermatogenesis at the elongated spermatid stage.
• Male Sirt6-deficient mice were completely infertile with a significant increase in apoptotic spermatids.
• The deacetylase activity of SIRT6 on H3K9ac, H3K18ac, and H3K56ac was found not to be required for spermatogenesis.

Conclusions:

• SIRT6 plays a critical and previously unrecognized role in male spermatogenesis and fertility.
• Spermatogenesis defects in Sirt6-deficient mice are not solely dependent on its canonical histone deacetylase activities.
• This study establishes a novel link between SIRT6 and male reproductive health.