Delbridge, MargaretLongepied, GuyDepetris, DanielleMattei, Marle-GenevieveDisteche, Christine MGraves, JenniferMitchell, Michael J2015-12-132015-12-130967-3849http://hdl.handle.net/1885/81072TSPY, a candidate gene for a factor that promotes gonadoblastoma formation (GBY), is a testis-specific multicopy gene family in the male-specific region of the human Y (MSY) chromosome. Although it was originally proposed that male-specific genes on the Y originated from a transposed copy of an autosomal gene (Lahn & Page 1999b), at least two male-specific genes (RBMY and SRY) descended from a formerly recombining X-Y identical gene pair. Here we show that a TSPY homologue with similar gene structure lies in conserved positions, close to SMCX, on the X chromosome in human (TSPX) and mouse (Tspx). TSPX is widely expressed and subject to X inactivation. TSPX and TSPY therefore evolved from an identical gene pair on the original mammalian sex chromosomes. This supports the hypothesis that even male-specific genes on the Y chromosome may have their origin in ubiquitously expressed genes on the X. It also strengthens the case for TSPY as a candidate for GBY, since independent functional studies link TSPX to cell cycle regulation.Keywords: animal cell; article; cell cycle; chromosome inactivation; controlled study; gene; gene expression; gene structure; gonadoblastoma; human; human cell; mouse; multigene family; nonhuman; nucleotide sequence; priority journal; RBMY gene; sex chromosome; SRY evolution; TSPY; X chromosome; Y chromosome200410.1023/B:CHRO.0000034134.91243.1c2015-12-11