title: Mutations affecting gonadal development in Medaka, Oryzias latipes.
abstract: A gonad is formed from germ cells and somatic mesodermal cells through their interactions. Its development is coupled with the determination and differentiation of the sex and sex-associated traits. We carried out a large-scale screening of Medaka mutants in which gonadal development is affected. Screening was performed on larvae at 8 days posthatching for abnormal abundance and/or distribution of germ cells detected by the in situ hybridization for olvas (Medaka vasa). We describe here 16 mutants of 13 genes, which are classified into four groups. Group 1, consisting of four mutants of three genes kon, tot) characterised by an increase in germ cell number. An adult tot homozygote fish has the characteristic feature of possessing hypertrophic gonads filled with immature oocytes. Group 2, represented by a single gene (zen) mutant characterized by a gradual loss of germ cells. Group 3, consisting of four mutants of distinct genes (eko, eki, sht, ano) showing irregular clustering of germ cells. Group 4, consisting of seven mutants of five genes (arr, hyo, mzr, hdr, fbk) showing fragmented clusters of germ cells. In some mutants belonging to Groups 1, 3 and 4, the expression level of ftz-f1 (sf-1/Ad4BP) in gonadal somatic cells significantly decreased, suggesting that interaction between somatic and germ cells is affected.
authors.affiliation: Japan Science and Technology Agency, ERATO, Kondoh Differentiation Signaling Project/SORST, Kondoh Research Group, Kyoto 606-8305, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Morinaga
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tomonaga
authors.forename: Takao
authors.initials: T
authors.lastname: Sasado
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suwa
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Niwa
authors.forename: Akihito
authors.initials: A
authors.lastname: Yasuoka
authors.forename: Thorsten
authors.initials: T
authors.lastname: Henrich
authors.forename: Tomomi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tomonori
authors.initials: T
authors.lastname: Deguchi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yoda
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Hirose
authors.forename: Norimasa
authors.initials: N
authors.lastname: Iwanami
authors.forename: Sanae
authors.initials: S
authors.lastname: Kunimatsu
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Ai
authors.initials: A
authors.lastname: Shinomiya
authors.forename: Minoru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Hisato
authors.initials: H
authors.lastname: Kondoh
authors.forename: Makoto
authors.initials: M
authors.lastname: Furutani-Seiki
mesh_terms: D000818:Animals; D005260:Female; D005854:Germ Cells / Q000378:metabolism; D006066:Gonads / Q000166:cytology / Q000196:embryology*; D008297:Male; D009154:Mutation; D009990:Oryzias / Q000196:embryology* / Q000235:genetics*; D010641:Phenotype