title: Expression of the estrogen receptor alpha gene in the anal fin of Japanese medaka, Oryzias latipes, by environmental concentrations of bisphenol A.
abstract: The anal fin in Japanese medaka, Oryzias latipes, is a typical sexual secondary character. In the present study, we focused on this organ and examined the effects of low doses of a natural estrogen, 17beta-estradiol (E(2)), and an environmental xenoestrogen, bisphenol A (BPA), in vivo by monitoring estrogen receptor (ER) alpha gene expression. Groups of adult male and female medaka were immersed in 10(-9) M E(2) or 10(-10) to 10(-8) M BPA and the levels of ERalpha gene transcripts in the anal fins were measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). One day of treatment with each concentration of BPA examined and 10(-9) M E(2) increased the levels of ERalpha mRNA in female anal fins by 3-fold as compared with controls. In the male specimens, neither 10(-9) M E(2) nor 10(-10) M BPA showed remarkable effects on the anal fins as compared with the results in females, but 10(-9) and 10(-8) M BPA increased the levels of ERalpha mRNA by 2.3- and 3.3-fold with 1 day of exposure, respectively. The present results showed that medaka anal fins may be a sensitive bio-indicator for screening of environmental estrogenic chemicals.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hayashi
authors.forename: Ayano
authors.initials: A
authors.lastname: Nishimoto
authors.forename: Noriko
authors.initials: N
authors.lastname: Oshima
authors.forename: Shawichi
authors.initials: S
authors.lastname: Iwamuro
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds; D004958:Estradiol / Q000633:toxicity*; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D008297:Male; D009990:Oryzias / Q000235:genetics*; D010636:Phenols / Q000633:toxicity*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014873:Water Pollutants / Q000633:toxicity*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004958:Estradiol; D047628:Estrogen Receptor alpha; D010636:Phenols; D014873:Water Pollutants; C006780:bisphenol A; D000098826:Bisphenol A Compounds