title: Expression of gonadal soma derived factor (GSDF) is spatially and temporally correlated with early testicular differentiation in medaka.
abstract: In the teleost fish, medaka (Oryzias latipes), the sex is genetically determined at the time of fertilization. The males are heterogametic with XY chromosome composition, while females are of XX chromosome composition. The male sexual differentiation is initiated in XY embryos of medaka by the sex-determining gene Dmy. In this study, we have cloned the gonadal soma derived factor (Gsdf) from medaka and characterized its expression pattern during the initiation of morphological testicular differentiation. By real-time PCR, an XY-specific up-regulation was detected in the expression levels of Gsdf in the whole embryos of medaka at 6days post fertilization (dpf), coincident with the initiation of testicular differentiation in the XY gonads. Whole mount and section in situ hybridizations reaffirmed that Gsdf was expressed exclusively in primordial gonads of only the genetic males at 6dpf. Conversely, the expression of Gsdf was found to be very weak in the XX gonads during embryogenesis. Importantly, Gsdf and Dmy were found to be co-localized in the same somatic cells in the XY gonads. When the XY embryos were treated with estradiol-17beta, in order to reverse their phenotypic sex, a decline was observed in the expression of Gsdf in these embryos by real-time PCR.
authors.affiliation: Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shibata
authors.forename: Bindhu
authors.initials: B
authors.lastname: Paul-Prasanth
authors.forename: Aya
authors.initials: A
authors.lastname: Suzuki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Usami
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakamoto
authors.forename: Masaru
authors.initials: M
authors.lastname: Matsuda
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nagahama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian; D005260:Female; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000378:metabolism / Q000502:physiology; D006066:Gonads / Q000196:embryology / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009990:Oryzias / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012733:Sex Differentiation / Q000235:genetics*; D013737:Testis / Q000196:embryology / Q000378:metabolism*; D013997:Time Factors
chemical_list: D029941:Fish Proteins