Two genes substitute for the mouse Y chromosome for spermatogenesis andă reproduction

International audienceThe mammalian Y chromosome is considered a symbol of maleness, as ită encodes a gene driving male sex determination, Sry, as well as a batteryă of other genes important for male reproduction. We previouslyă demonstrated in the mouse that successful assisted reproduction can beă achieved when the Y gene contribution is limited to only two genes, Sryă and spermatogonial proliferation factor Eif2s3y. Here, we replaced Sryă by transgenic activation of its downstream target Sox9, and Eif2s3y, byă transgenic overexpression of its X chromosome-encoded homolog Eif2s3x.ă The resulting males with no Y chromosome genes produced haploid maleă gametes and sired offspring after assisted reproduction. Our findingsă support the existence of functional redundancy between the Y chromosomeă genes and their homologs encoded on other chromosomes