GSE136769
Rare mutations in the complement regulatory gene CSMD1 are associated with male and female infertility
Infertility in men and women is a common and complex genetic trait with shared biological bases between the sexes. We performed a series of rare variant analyses across 73,185 women and men to identify genes that contribute to primary gonadal dysfunction and identified CSMD1 as a strong candidate in both sexes. CSMD1 is a complement regulatory protein on chromosome 8p23. In order to interpret and support our genetic findings, we performed detailed transcriptomic and protein-based experiments which found CSMD1 enriched at the germ-cell/somatic-cell interface in both male and female gonads. We then performed a battery of tests on Csmd1 knockout mice. Knockout males show increased rates of infertility, and present testes with severe histological degeneration and significantly increased deposition of complement C3 protein. Knockout females show significant reduction in ovarian quality and breeding success, as well as impaired branching of the mammary glands.  Furthermore, double knockout of Csmd1 and C3 leads to an unexpected and non-additive reduction in breeding success, suggesting that CSMD1 and the complement pathway play an important role in the normal postnatal development of the gonads in both sexes. Overall design: RNA-seq of mouse whole ovaries, whole testes, and FACS purified germ cell subpopulations