为研究17α-甲基睾酮(17 α-methyltestosteron,MT)对生长发育期间的雌性食蚊鱼形态雄性化及目标基因表达的影响,并探讨臀鳍雄激素受体基因(ARα) mRNA表达水平作为监测养殖水体雄激素类污染物的有效生物学标记的可行性,使用浸浴法以0.5、5、50和500 nmol/L 4个MT浓度为雌性食蚊鱼幼鱼染毒,设置对照组和平行组,暴露实验持续21 d,定量测定了幼鱼体长(BL)、体质量(BW)、身体健康指数(CF)以及臀鳍第3鳍条长度(FL)、分节数(FJ)和最宽处宽度(FW)；ARα mRNA的表达水平.结果显示:与对照组相比,雌性幼鱼暴露21 d后BL、CF均没有显著变化,只有高浓度组(50和500 nmol/L)食蚊鱼的BW有显著下降(P＜0.05)；雌性幼鱼臀鳍第3鳍条FJ显著增加,FL随之延长,并且FW也出现显著增宽(P＜0.05)；雌性幼鱼暴露于MT21 d之后,ARα mRNA表达水平呈现与剂量相关的上升(P＜0.05).MT的雄激素效应明显,导致雌鱼在生长发育过程中出现形态雄性化；ARα基因mRNA表达水平可作为监测养殖水体雄激素类污染物有效的生物标记.%The effects of 17a-methyltestosterone ( MT) on target gene expression and morphological masculinization in female mosquitofish (Gambusia affinis) during the growth and development is studied in order to test if the level of ARa mRNA expression in mosquitofish can be considered a valid biomarker for aquaculture androgen POPs. With juvenile female mosquitofish exposed to MT with 0. 5,5,50 and 500 nmol/L for 21 d,the body length(BL) ,body weight(BW) ,body health index(CF) ,and the anal fin 3rd fin section length (FL) ,the section number (FJ) ,and the most wide department width (FW) ,as well as the level of ARa mRNA and VTGa mRNA expression were quantitatively determined by morphology and in vitro methods,and set the control group and the parallel groups. The results showed that the BL and CF in female juvenile exposed to different concentrations of MT for 21 d were not significantly different, only the BW in fish exposed to 50 and 500 nmol/L of high-dose groups was significantly decreased ( P < 0.05) when compared with the control group;the FJ in 3rd fin of anal fin showed a significant increase,FL was along with extending and FW also showed a significant increase in width ( P < 0. 05); Female juveniles were exposed to different concentrations of MT after 21 d,ARa mRNA expression level was displayed dose-related increase significantly ( P < 0. 05). The results indicated that the androgenic effects of MT was very significant, resulting in the morphological masculinization in female mosquitofish during the growth and development process; ARa mRNA expression levels could be used as the ideal biomarkers for monitoring the aquaculture water androgen pollutants.
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