TY - JOUR
T1 - Androgen receptor of the frog Rana rugosa
T2 - Molecular cloning and its characterization
AU - Yokoyama, Satoshi
AU - Oshima, Yuki
AU - Tokita, Junpei
AU - Suda, Mari
AU - Shinozuka, Takuma
AU - Nakamura, Masahisa
PY - 2009
Y1 - 2009
N2 - The androgen receptor(AR) gene is located on the Z and W sex chromosomes in the frog Rana rugosa, designated Z- and W-AR, respectively. Among various tissues of an adult frog, AR expression levels were highest in the testis and brain. In the testis, AR was expressed in germ cells. AR expression occured in developing embryos from stage 21 and was very high in the gonad of a male tadpole before the onset of sex determination. When Z- and W-AR were expressed in Xenopus A6 cells, they activated androgen-dependent transcription of a luciferase reporter gene. By contrast, estrogen receptor (ER) a and b showed no sexually dimorphic expression during sex determination, but their expressions became much higher in the gonad of a female tadpole after sex determination. In addition, AR transcripts in the ZZ-tadpoles were twice as abundant as in the ZW genotype. In contrast, W-AR expression was extremely low although when W-AR was expressed in A6 cells, it activated transcription in the luciferase assay. In this regard it is worth noting that the promoter regions of Z- and W-AR are not identical. The results suggest that Z-AR plays an important role in the testis formation in a R. rugosa tadpole, whereas ERb is involved in ovary differentiation. Very low expression of W-AR may be due to its promoter region having mutations in key transcription factor binding sites, although these remain to be identified. Thus, it is proposed that AR could be a candidate for a male-determining gene in R. rugosa.
AB - The androgen receptor(AR) gene is located on the Z and W sex chromosomes in the frog Rana rugosa, designated Z- and W-AR, respectively. Among various tissues of an adult frog, AR expression levels were highest in the testis and brain. In the testis, AR was expressed in germ cells. AR expression occured in developing embryos from stage 21 and was very high in the gonad of a male tadpole before the onset of sex determination. When Z- and W-AR were expressed in Xenopus A6 cells, they activated androgen-dependent transcription of a luciferase reporter gene. By contrast, estrogen receptor (ER) a and b showed no sexually dimorphic expression during sex determination, but their expressions became much higher in the gonad of a female tadpole after sex determination. In addition, AR transcripts in the ZZ-tadpoles were twice as abundant as in the ZW genotype. In contrast, W-AR expression was extremely low although when W-AR was expressed in A6 cells, it activated transcription in the luciferase assay. In this regard it is worth noting that the promoter regions of Z- and W-AR are not identical. The results suggest that Z-AR plays an important role in the testis formation in a R. rugosa tadpole, whereas ERb is involved in ovary differentiation. Very low expression of W-AR may be due to its promoter region having mutations in key transcription factor binding sites, although these remain to be identified. Thus, it is proposed that AR could be a candidate for a male-determining gene in R. rugosa.
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U2 - 10.1002/jez.568
DO - 10.1002/jez.568
M3 - Article
C2 - 19722274
AN - SCOPUS:70449395829
VL - 311
SP - 796
EP - 812
JO - Journal of Experimental Zoology Part A: Ecological Genetics and Physiology
JF - Journal of Experimental Zoology Part A: Ecological Genetics and Physiology
SN - 1932-5223
IS - 10
ER -