Expression profiling of mouse ing2 -/- mice with spermatogenic arrest and infertility

Expression profiling of mouse ing2 -/- testis vs WT reveals gene expression differences consistent with spermatogenic arrest and infertility. Ing2 is indispensable for male germ cell development in mice. While mice deficient for Ing2 were born and grew without apparent abnormalities, male, but not female, were infertile, consistent with the highest expression of Ing2 in testes in wild-type mice and in humans. Histological and DNA content analyses in Ing2-/- testes revealed a spermatogenesis arrest at meiotic phase and enhanced apoptosis associated with increased p53, resulting in a decline in mature spermatozoa, which became more severe in older age. HDAC1 accumulation and core histone deacetylation at pachytene stage were impaired in Ing2-/- testes, suggesting that the recruitment of HDAC1 by Ing2 plays a critical role in spermatogenesis. This study establishes Ing2 as a novel mammalian regulator of spermatocyte differentiation, which coordinates spermatogenesis stage-specific histone modifications. This study has implications in understanding human male infertility. Testis from WT and Ing2 KO mice at 2-3 months of age where analyzed for differences in gene expression.