title: A transgenic medaka line with visible markers for genotypic and phenotypic sex.
abstract: Accurate genotyping of sex is required for correct interpretation in any in vivo assays with endocrine disrupting chemicals (EDCs). Visible markers for genotypic sex, if reliable, simplify assays because time-consuming PCR-based genotyping can be skipped. Here, we describe a line of Japanese medaka with a brain-expressed green fluorescent protein (GFP) transgene inserted near the sex-determining locus. When used with a white pigment cell marker, genotypic sex can be determined reliably as early as 3 days after fertilization (well before gonadal sex differentiation). No recombinants were found in more than 2000 progenies. We also introduced a strong ovarian GFP marker into the line with these genetic sex markers, so that phenotypic sex can also be determined reliably at 8 days after hatching. Well-known sex reversal protocols using exogenous steroid treatments of embryos were monitored by this transgenic line, demonstrating the line to be a useful tool for in vivo studies utilizing gonadal sex differentiation of the medaka, especially for screenings of potential estrogenic and androgenic EDCs.
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan. kanamori@bio.nagoya-u.ac.jp
authors: Akira
authors: A
authors: Kanamori
authors: Keiko
authors: K
authors: Toyama
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000235:genetics; D009990:Oryzias / Q000235:genetics*; D010641:Phenotype; D012733:Sex Differentiation / Q000187:drug effects; D013256:Steroids / Q000494:pharmacology
chemical_list: D013256:Steroids; D049452:Green Fluorescent Proteins