title: Developmental disorders and altered gene expression in the tropical clawed frog (Silurana tropicalis) exposed to 17α-ethinylestradiol.
abstract: Several endocrine-disrupting chemicals with estrogenic activity can affect sexual development and reproduction in aquatic wildlife. The occurrence of oocytes in the testis (testis-ova) is one reproductive disorder and can be used as a valid endpoint when studying disruptive effects of estrogenic chemicals. To elucidate the molecular basis of testis-ova induction, we conducted gene expression analysis in the gonads of Silurana tropicalis exposed to 0, 3, 10 and 30 ng l(-1) 17α-ethinylestradiol (EE2) from 2 days after fertilization to the juvenile stage (14 weeks after fertilization). The frequencies of testis-ova induction or male to female sex-reversal of the gonads increased in an EE2 dose-dependent manner. Microarray analysis showed that expressions of a large number of genes were significantly changed by EE2 exposure. Genes including egg envelope composition (zp4, zpax, zpc, zp3.2 and egg cortical granule lectin), 42S particle genes (42Sp50, 42Sp43 and 42Sp48) and regulation of female germ cells (figla) are associated with the testis-ova and sex-reversal situation in the gonads. Of those, expression of zpc and 42Sp50 genes is associated with testis-ova. Thus, we propose that these genes are useful biomarkers for toxicological research in amphibians developmentally exposed to estrogenic chemicals.
authors.affiliation: The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, 753-8513, Japan.
authors.forename: Ikumi
authors.initials: I
authors.lastname: Hirakawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyagawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Mitsui
authors.forename: Maki
authors.initials: M
authors.lastname: Miyahara
authors.forename: Yuta
authors.initials: Y
authors.lastname: Onishi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kagami
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Kusano
authors.forename: Takashi
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ohta
authors.forename: Taisen
authors.initials: T
authors.lastname: Iguchi
mesh_terms: D000818:Animals; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism; D052244:Endocrine Disruptors / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D010641:Phenotype; D012098:Reproduction / Q000187:drug effects; D013737:Testis / Q000187:drug effects / Q000378:metabolism; D014981:Xenopus / Q000378:metabolism*
chemical_list: D004527:Egg Proteins; D052244:Endocrine Disruptors; D004997:Ethinyl Estradiol
keywords: 17α-ethinylestradiol; Silurana tropicalis; developmental exposure; microarray; testis-ova