title: Knock-down of DMY initiates female pathway in the genetic male medaka, Oryzias latipes.
abstract: DMY is the second vertebrate sex-determining gene identified from the fish, Oryzias latipes. In this study, we used two different ways of sex reversal, DMY knock-down and estradiol-17beta (E2) treatment, to determine the possible function of DMY during early gonadal sex differentiation in XY medaka. Our findings revealed that the mitotic and meiotic activities of the germ cells in the 0 day after hatching (dah) DMY knock-down XY larvae were identical to those of the normal XX larvae, suggesting the microenvironment of these XY gonads to be similar to that of the normal XX gonad, where DMY is naturally absent. Conversely, E2 treatment failed to initiate mitosis in the XY gonad, possibly due to an active DMY, even though it could initiate meiosis. Present study is the first to prove that the germ cells in the XY gonad can resume the mitotic activity, if DMY was knocked down.
authors.affiliation: Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Bindhu
authors.initials: B
authors.lastname: Paul-Prasanth
authors.forename: Masaru
authors.initials: M
authors.lastname: Matsuda
authors.forename: En-Lieng
authors.initials: EL
authors.lastname: Lau
authors.forename: Aya
authors.initials: A
authors.lastname: Suzuki
authors.forename: Fumie
authors.initials: F
authors.lastname: Sakai
authors.forename: Tohru
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D029941:Fish Proteins / Q000235:genetics / Q000502:physiology*; D005854:Germ Cells / Q000187:drug effects / Q000254:growth & development; D006066:Gonads / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D057850:Hermaphroditic Organisms; D008297:Male; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D009990:Oryzias / Q000235:genetics / Q000254:growth & development*; D012730:Sex Chromosomes / Q000378:metabolism; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000235:genetics*
chemical_list: D029941:Fish Proteins; D004958:Estradiol