Involvement of androgen receptor in sex determination in an amphibian species.
In mice and humans, the androgen receptor (AR) gene, located on the X chromosome, is not known to be involved in sex determination. In the Japanese frog Rana rugosa the AR is located on the sex chromosomes (X, Y, Z and W). Phylogenetic analysis shows that the AR on the X chromosome (X-AR) of the Korean R. rugosa is basal and segregates into two clusters: one containing W-AR of Japanese R. rugosa, the other containing Y-AR. AR expression is twice as high in ZZ (male) compared to ZW (female) embryos in which the W-AR is barely expressed. Higher AR-expression may be associated with male sex determination in this species. To examine whether the Z-AR is involved in sex determination in R. rugosa, we produced transgenic (Tg) frogs carrying an exogenous Z-AR. Analysis of ZW Tg frogs revealed development of masculinized gonads or 'ovotestes'. Expression of CYP17 and Dmrt1, genes known to be activated during normal male gonadal development, were up-regulated in the ZW ovotestis. Testosterone, supplied to the rearing water, completed the female-to-male sex-reversal in the AR-Tg ZW frogs. Here we report that Z-AR is involved in male sex-determination in an amphibian species.
Department of Biology, Waseda University, Tokyo, Japan.
Jun
J
Fujii
Department of Biology, Waseda University, Tokyo, Japan.
Maho
M
Kodama
Department of Biology, Waseda University, Tokyo, Japan.
Akira
A
Oike
Department of Biology, Waseda University, Tokyo, Japan.
Yasuki
Y
Matsuo
Laboratory of Wildlife Conservation Genetics, Seoul National University, Seoul, South Korea.
Mi-Sook
MS
Min
Department of Biology, Nippon Medical School, Kawasaki, Kanagawa, Japan.
Takashi
T
Hasebe
Department of Biology, Nippon Medical School, Kawasaki, Kanagawa, Japan.
Atsuko
A
Ishizuya-Oka
Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka, Japan.
Koichi
K
Kawakami
Department of Biology, Waseda University, Tokyo, Japan.
Masahisa
M
Nakamura
D000818:Animals; D030801:Animals, Genetically Modified; D004625:Embryo, Nonmammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D010802:Phylogeny; D011898:Ranidae / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D012730:Sex Chromosomes; D019849:Sex Determination Processes / Q000187:drug effects / Q000235:genetics; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013739:Testosterone / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
C110547:DMRT1 protein; D011944:Receptors, Androgen; D014157:Transcription Factors; D013739:Testosterone; D013254:Steroid 17-alpha-Hydroxylase