Distinct expression of three estrogen receptors in response to bisphenol A and nonylphenol in male Nile tilapias (Oreochromis niloticus).
Environmental estrogens, such as bisphenol A (BisA) and nonylphenol (NP), have been shown to affect the estrogen receptor (ER) expression and induce male reproductive abnormalities. To elucidate molecular mechanisms of action of xenoestrogenic chemicals on the expression of estrogen receptors in the testes of Nile tilapia (Oreochromis niloticus), three full-length cDNAs respectively encoding ntERalpha, ntERbeta1 and ntERbeta2 were cloned from testes. The amino acid sequences of ntERalpha, ntERbeta1 and ntERbeta2 showed a high degree of similarity to the relevant fish species. Tissue-specific expression study showed that three receptors were highly expressed in pituitary, liver, testis, kidney and intestine tissues. The ntERalpha, ntERbeta1 and ntERbeta2 mRNA expressions were significantly higher at the sexual early recrudescing stage than at other recrudesced stages. After being exposed to xenoestrogens from weeks 2 to 4, the ntERalpha mRNA levels were increased significantly in testes after NP treatment at all sampling times or after 4 weeks of exposure to BPA. The ntERbeta1 mRNA levels remained unchanged, while a significant decrease of the ntERbeta2 mRNA level was observed in testes after exposure to NP and BPA. The present study demonstrates that the regulation of all three ntER subtypes in testes may act via different molecular mechanisms of exposure to NP and BPA.
Huang
Weiren
W
State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-Sen University, Guangzhou 510275, China.
Zhang
Yong
Y
Jia
Xiaoping
X
Ma
Xilan
X
Li
Shuisheng
S
Liu
Yun
Y
Zhu
Pei
P
Lu
Danqi
D
Zhao
Huihong
H
Luo
Wenna
W
Yi
Shibai
S
Liu
Xiaochun
X
Lin
Haoran
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001559:Benzhydryl Compounds; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004968:Estrogens, Non-Steroidal / Q000633:toxicity*; D029941:Fish Proteins / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D008969:Molecular Sequence Data; D010636:Phenols / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011960:Receptors, Estrogen / Q000145:classification / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D017210:Tilapia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014018:Tissue Distribution; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D017931:DNA Primers; D004968:Estrogens, Non-Steroidal; D029941:Fish Proteins; D010636:Phenols; D012333:RNA, Messenger; D011960:Receptors, Estrogen; C025256:nonylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds