Mutations affecting gonadal development in Medaka, Oryzias latipes.
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.
Morinaga
Chikako
C
Japan Science and Technology Agency, ERATO, Kondoh Differentiation Signaling Project/SORST, Kondoh Research Group, Kyoto 606-8305, Japan.
Tomonaga
Takeshi
T
Sasado
Takao
T
Suwa
Hiroshi
H
Niwa
Katsutoshi
K
Yasuoka
Akihito
A
Henrich
Thorsten
T
Watanabe
Tomomi
T
Deguchi
Tomonori
T
Yoda
Hiroki
H
Hirose
Yukihiro
Y
Iwanami
Norimasa
N
Kunimatsu
Sanae
S
Okamoto
Yasuko
Y
Yamanaka
Toshiyuki
T
Shinomiya
Ai
A
Tanaka
Minoru
M
Kondoh
Hisato
H
Furutani-Seiki
Makoto
M
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