The histone H3 lysine 36 demethylase KDM2A/FBXL11 is essential for germ cell development in male mice [RNA-Seq]

KDM2A/FBXL11 is a Jumonji-domain containing lysine demethylase catalyzing the removal of mono- and di-methyl modifications of histone H3 lysine 36. While Kdm2a is required for mouse embryogenesis, its role in adult physiology is unknown. Using conditional deletion approaches, we demonstrate that Kdm2a deficiency causes testicular atrophy and male infertility. Though spermatogonial stem cells were unaffected, proliferating and differentiating spermatogonia suffered from delayed cell cycle progression and apoptosis, which correlated with upregulated expression of several cell cycle inhibitors. Loss of Kdm2a in spermatocytes disrupted progression through meiotic prophase, as shown by impaired chromosome synapsis and processing of meiotic double strand breaks, and by altered chromatin states. Correspondingly, Kdm2a mutant spermatocytes failed to activate numerous genes controlling these processes. RNA-sequencing analyses on purified spermatogonia and spermatocytes showed that during normal spermatogonial differentiation over 700 genes undergo repression, which is controlled by KDM2A. CpG-rich promoter genes upregulated in Kdm2a deficient cells are marked by Polycomb Repressive Complexes (PRC) and associated modifications in wildtype male germ cells, suggesting that KDM2A is required for PRC-mediated repression. Our study thus identifies critical roles for KDM2A in coordinating gene expression programs during spermatogonial differentiation and meiosis, which are essential for male germ cell development.