Endocrine disrupting chemicals (bisphenol A, 4-nonylphenol, 4-tert-octylphenol) modulate expression of two distinct cytochrome P450 aromatase genes differently in gender types of the hermaphroditic fish Rivulus marmoratus.
To understand the effect of endocrine-disrupting chemicals (EDCs) on cytochrome P450 aromatase (rm-cyp19) gene expression between gender types in the hermaphroditic fish Rivulus marmoratus, we cloned two distinct rm-cyp19 genes using RT-PCR with degenerative primers, obtained full-length cDNAs using 5'- and 3'-RACE-PCR methods, and completely sequenced them. The brain aromatase (rm-cyp19b) cDNA consisted of 2,124 bp including the open reading frame (ORF), which encoded a putative protein of 505 amino acids. The ovarian aromatase (rm-cyp19a) cDNA consisted of 2,075 bp, including the ORF encoding a putative protein of 516 amino acids. Expression patterns of rm-cyp19b and rm-cyp19a mRNAs were investigated in embryos of different developmental stages and in seven different tissues of adult fish. The rm-cyp19b gene in hermaphrodite and secondary male R. marmoratus was predominantly expressed in the brain, while the rm-cyp19a gene was expressed gender-specifically in the gonad. The expression of rm-cyp19b mRNA increased from stage 1 (2 d post fertilization) to stage 4 (12 d post fertilization) in a developmental stage-dependent manner but steeply decreased in the hatching stage. Compared to the rm-cyp19b gene, the abundance of ovarian aromatase rm-cyp19a transcripts was very low, and its expression was first detected at stage 3 and then decreased gradually to the hatching stage. Alteration of rm-cyp19b and rm-cyp19a gene expression was further analyzed in the brain and gonad by real-time RT-PCR 96 h after EDC exposure in hermaphrodites and secondary males. The brain aromatase rm-cyp19b gene was up-regulated in the brain after 4-nonylphenol (4-NP)-exposure, while the ovarian aromatase rm-cyp19a gene was significantly down-regulated in the gonad. In 300 microg/L 4-tert octylphenol (4-tert-OP), or 600 microg/L bisphenol A-exposed brain and gonad, both rm-cyp19b and rm-cyp19a genes were up-regulated. In the case of secondary males, the rm-cyp19b gene was highly expressed in the 4-NP-exposed brain, while expression of the rm-cyp19a gene was not detected in the gonad. These results indicate that the expression of rm-cyp19a and rm-cyp19b genes is differently modulated according to estrogenic compounds and gender type of R. marmoratus.
Lee
Young-Mi
YM
Department of Molecular and Environmental Bioscience, and The National Research Lab for Marine Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, Republic of Korea.
Seo
Jung Soo
JS
Kim
Il-Chan
IC
Yoon
Yong-Dal
YD
Lee
Jae-Seong
JS
D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001559:Benzhydryl Compounds; D003532:Cyprinodontiformes / Q000235:genetics* / Q000502:physiology; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D052244:Endocrine Disruptors / Q000494:pharmacology*; D005260:Female; D005306:Fertilization / Q000235:genetics / Q000502:physiology; D005399:Fishes; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D006066:Gonads / Q000201:enzymology; D008297:Male; D008969:Molecular Sequence Data; D010053:Ovary / Q000378:metabolism; D010636:Phenols / Q000494:pharmacology; D012737:Sex Factors; D000098826:Bisphenol A Compounds
D001141:Aromatase; D001559:Benzhydryl Compounds; D003577:Cytochrome P-450 Enzyme System; D018076:DNA, Complementary; D052244:Endocrine Disruptors; D010636:Phenols; C041594:4-nonylphenol; C105260:4-tert-octylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds