DMY gene induces male development in genetically female (XX) medaka fish

Abstract

Although the sex-determining gene SRY/Sry has been identified in mammals, homologues and genes that have a similar function have yet to be identified in nonmammalian vertebrates. Recently, DMY (the DM -domain gene on the Y chromosome) was cloned from the sex-determining region on the Y chromosome of the teleost fish medaka ( Oryzias latipes ). DMY has been shown to be required for the normal development of male individuals. In this study, we show that a 117-kb genomic DNA fragment that carries DMY is able to induce testis differentiation and subsequent male development in XX (genetically female) medaka. In addition, overexpression of DMY cDNA under the control of the CMV promoter also caused XX sex reversal. These results demonstrate that DMY is sufficient for male development in medaka and suggest that the functional difference between the X and Y chromosomes in medaka is a single gene. Our data indicate that DMY is an additional sex-determining gene in vertebrates.

Gonadal soma-derived factor (gsdf), a TGF-beta superfamily gene, induces testis differentiation in the teleost fish Oreochromis niloticus

“…Additionally, Dmrt1 is expressed in the germ cell-surrounding cells and intratesticular efferent ducts after testicular differentiation in medaka, a teleost fish, similarly to its expression in tilapia (Kobayashi et al, 455 2008(Kobayashi et al, 455 , 2004. However, the sex-determining gene dmy/dmrt1Yb, a dmrt1 paralog, showed the same localization as dmrt1 prior to sex differentiation (Kobayashi et al, 2008;Matsuda et al, 2007Matsuda et al, , 2002. Recently, a DNA-binding domain mutant of dmrt1 in medaka was shown to cause ovarian differentiation in XY individuals, suggesting that dmrt1 is required for testis differentiation after dmy sex determination .…”

No amicable divorce? Challenging the notion that sexual antagonism drives sex chromosome evolution

“…The absence of Sry from non-mammalian vertebrates and from egg-laying mammals [95] indicates that this mechanism of sex determination, and hence the therian Y chromosome, was acquired relatively recently. A single, Y-linked dominant gene DMY also determines sex in the medaka fish Oryzias latipes [96] but is absent from closely related species [97], indicating recent acquisition of a novel sex-determination system. In birds, the Z-linked gene DMRT1 forms a strong candidate for dosage-dependent single-gene sex determination [98], although the possibility that DMRT1 is regulated by upstream factors cannot be excluded.…”

A sex-determining region on the Y chromosome controls the sex-reversal ratio in interspecific hybrids between Oryzias curvinotus females and Oryzias latipes males

“…In the medaka, Oryzias latipes, which has an XX/XY sex-determining system (Aida, 1921), DMY was found to be the Y-specific sex-determining gene (Matsuda et al, 2002(Matsuda et al, , 2007. In this fish species, many sex-reversal mutants (XX males and XY females) have been found in wild populations Otake et al, 2006Otake et al, , 2008.…”