• G6PC3 is predominantly expressed in pachytene spermatocytes and localized to the sex body (XY body), suggesting a role in male germ cell development.
• CRISPR-Cas9-mediated G6pc3 knockout in mice leads to complete meiotic arrest at the pachytene stage and sterility.
• G6pc3 deficiency disrupts XY body formation and impairs meiotic sex chromosome inactivation (MSCI), highlighting its essential role in meiotic progression.
• These findings identify G6PC3 as a novel regulator of spermatogenesis, providing insights into mechanisms of male infertility.