title: Tracing the emergence of a novel sex-determining gene in medaka, Oryzias luzonensis.
abstract: Three sex-determining (SD) genes, SRY (mammals), Dmy (medaka), and DM-W (Xenopus laevis), have been identified to date in vertebrates. However, how and why a new sex-determining gene appears remains unknown, as do the switching mechanisms of the master sex-determining gene. Here, we used positional cloning to search for the sex-determining gene in Oryzias luzonensis and found that GsdfY (gonadal soma derived growth factor on the Y chromosome) has replaced Dmy as the master sex-determining gene in this species. We found that GsdfY showed high expression specifically in males during sex differentiation. Furthermore, the presence of a genomic fragment that included GsdfY converts XX individuals into fertile XX males. Luciferase assays demonstrated that the upstream sequence of GsdfY contributes to the male-specific high expression. Gsdf is downstream of Dmy in the sex-determining cascade of O. latipes, suggesting that emergence of the Dmy-independent Gsdf allele led to the appearance of this novel sex-determining gene in O. luzonensis.
authors.affiliation: Institute of Science and Technology, Niigata University, Niigata 950-2181, Japan. f09m004a@mail.cc.niigata-u.ac.jp
authors.forename: Taijun
authors.initials: T
authors.lastname: Myosho
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Otake
authors.forename: Haruo
authors.initials: H
authors.lastname: Masuyama
authors.forename: Masaru
authors.initials: M
authors.lastname: Matsuda
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kuroki
authors.forename: Asao
authors.initials: A
authors.lastname: Fujiyama
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Naruse
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hamaguchi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Sakaizumi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019295:Computational Biology; D005260:Female; D005298:Fertility / Q000235:genetics; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009990:Oryzias / Q000235:genetics* / Q000502:physiology; D012727:Sex Characteristics; D012730:Sex Chromosomes / Q000235:genetics; D019849:Sex Determination Processes / Q000235:genetics*
chemical_list: D029941:Fish Proteins