雌二醇、壬基酚和三丁基锡对斑马鱼雌激素响应基因表达的影响

Combined Effects of 17β-Estradiol, Nonylphenol, and Tributyltin on Estrogen-Responsive Genes of Zebrafish (Danio rerio)

为研究天然雌激素、环境拟雌激素和环境抗雌激素共存条件下的雌激素效应,分别以雌二醇(17β-estradiol,E2)、壬基酚(Nonylphenol,NP)和三丁基锡(Tributyltin,TBT)为代表,采用实时荧光定量PCR和相对定量分析法,测试并分析了3种污染物单独和不同组合联合暴露条件下成年雄性斑马鱼(Danio rerio)肝脏组织中雌激素响应基因vtg1、esr1、esr2a和esr2b mRNA的相对表达情况。结果显示:E2和NP的联合暴露,会显著诱导vtg1和esr1 mRNA的表达,且其相对表达量远高于两者单独暴露时的表达量之和。E2和TBT的联合暴露中,当TBT浓度较高(100 ng/L)而E2浓度较低(10 ng/L)时,TBT能够抑制E2对vtg1和esr1 mRNA表达的诱导作用。NP和TBT的联合暴露,会导致vtg1和esr1 mRNA的相对表达量远小于两者单独暴露时的表达量之和。而在E2、NP和TBT三者共同暴露中,当TBT浓度较高(100 ng/L),且E2和NP浓度较低(E2 10 ng/L,NP 25μg/L)时,TBT能抑制E2和NP对vtg1 mRNA表达的诱导作用。由此可见,不同类型环境雌激素共存条件下的联合效应与各组分的浓度配比有关,本研究结果为探索多种环境雌激素类污染物共存条件下的生物效应和生态风险提供了科学依据。

To study the combined effects of native estrogen,estrogen-like chemical and anti-estrogenic,the expression of hepatic vtg1,esr1,esr2a and esr2b mRNA in adult zebrafish(Danio rerio)was observed by using real-time PCR methodology under single and combined exposure conditions of three typical estrogens,17β-estradiol(E2),nonylphenol(NP)and tributyltin chloride(TBT),for 14 days.The results show that,the combined exposure of E2 and NP could induce the expression of vtg1 and esr1 mRNA,and the relative expression levels are much higher than the sum of that exposed in E2 and NP alone.Only when E2 is at a low concentration(10 ng/L),TBT at a high concentration(100 ng/L)could inhibit the induced effect of E2 on the expression of vtg1 and esr1 mRNA.Under combined exposure of NP and TBT,the relative expression levels of vtg1 and esr1 mRNA are much lower than the sum of that under single exposure of NP and TBT.Only when both E2 and NP are at a low concentration(E2 10 ng/L,NP 25μg/L),TBT at a high concentration(100 ng/L)could inhibit the induced effect on the expression of vtg1 mRNA under the combined exposure of E2,NP and TBT.This study could provide scientific information for predicting the ecotoxicological effect and ecological risk of various environmental hormones in natural environment.