中文摘要：

应用食蚊鱼细胞色素P450芳香化酶基因（CYP19%）和卵黄蛋白原基因（VTG%）m RNA转录水平为指标,研究微量多氯联苯（PCBs）长时间暴露对成年雌性食蚊鱼CYP19%基因和VTG%基因表达的影响,并评价其对雌性食蚊鱼产生的形态雄性化效应。采用静水暴露实验模式,分别设置0.08、0.4、2和10μg·L-1PCBs浓度,并设置对照组和平行组,定量测定14 d和28 d性腺CYP19%和肝脏VTG%m RNA表达水平的变化,以及对椎体脉棘发育的影响。暴露实验结果显示：1各PCBs浓度组（0.08、0.4、2和10μg·L-1PCBs）暴露均能抑制食蚊鱼CYP19%和VTG基因的表达,表明PCBs对食蚊鱼VTG%基因的抑制远大于对食蚊鱼CYP19%基因的抑制;20.4μg·L-1PCBs暴露显著地降低了食蚊鱼第15椎体脉棘的长度并降低第15、16椎体脉棘的L/D值,显示食蚊鱼出现骨骼形态雄性化,表明一定浓度的PCBs暴露会表现出抗雌激素效应。

英文摘要：

The cytochrome P450 aromatase（CYP19ɑ ） and vitellogenin（VTGɑ ） genes m RNA transcriptional levels in mosquitofish（Gambusia affinis） were detected in order to investigate the effects of trace PCBs on the CYP19ɑ and VTGɑ expression in the adult female G. affinis for long time exposure, and evaluate its effect on the morphological masculinization in female G. affinis. G. affinis were randomly divided into five groups, with one control group and four experimental groups（0.08, 0.4, 2 and 10 μg·L-1PCBs）. Parallel experimental groups were also established.The CYP19ɑ and VTGɑ m RNA expression levels in fish gonad and liver tissues were determined after 14 and 28 d exposure, respectively. The effect of PCBs on the development of hemal spine was also detected. The exposure ex-periment results showed that： 1 different concentrations of PCBs group（0.08, 0.4, 2 and 10 μg·L-1PCBs） exposure could inhibit the G. affinis CYP19ɑ and VTGɑ gene expression, which suggested that the inhibition of PCBs on G.affinis VTGɑ gene was far greater than the inhibition of G. affinis CYP19ɑ gene; 2 0.4 μg·L-1PCBs exposure significantly reduced the length（L） of 15 th haemal spine, and reduced the L/D ratio of 15 th and 16 th haemal spine in G. affinis, which appeared masculinization of skeletal morphology. These showed that a certain concentration of PCBs exposure would show anti estrogen effect.