Enantioselectivity in the separation, toxicology, biodegradation and estrogenic activity of chiral pesticides has become a groundbreaking topic recently. In this study, real-time, quantitative polymerase chain reaction was adapted to investigate the induction of estrogen-responsive gene expression in embryo-larval zebrafish after 7 d of exposure to permethrin (PM) enantiomers. The PM enantiomers were completely separated by a chiral HPLC column. The in vivo study found that a 7 d exposure to 250 ng L(-1) PM racemate and its enantiomers was sufficient to stimulate vtg1, esralpha and cyp19b expression, while 1000 ng L(-1) exposure significantly induced gene expression in a pattern similar to that of the control (50 ng L(-1) E2), except for vtg2. Significant differences were detected between the enantiomers in the induction of estrogen-responsive gene expression. At the exposure level of 1000 ng L(-1), the vtg1, esralpha and cyp19b responses to the (-)-trans enantiomer were about 3.2-, 1.8- and 1.5-fold higher, respectively, than those in the group treated with (+)-trans enantiomer (p < 0.05). In the two cis-enantiomer treatment groups, (+)-cis increased the mRNA level of the cyp19b gene about 1.5-fold higher than the (-)-cis-enantiomer did. Of the four enantiomers, the (-)-trans enantiomer showed the greatest estrogenic activity. The results strongly indicate the occurrence of significant enantioselectivity in estrogenic activity of PM enantiomers exposed to embryo-larval zebrafish. These findings add to a growing body of evidence concerning enantioselectivity in the toxicity, endocrine-disrupting activity, and environmental biodegradation of chiral pesticides.

中文翻译：

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苄氯菊酯对映体在幼虫斑马鱼中对雌激素响应基因表达的对映选择性诱导。

最近，手性农药在分离，毒理学，生物降解和雌激素活性方面的对映选择性成为一个具有开创性的话题。在这项研究中，实时定量聚合酶链反应适用于调查暴露于氯菊酯（PM）对映体7 d后胚胎幼虫斑马鱼中雌激素响应基因表达的诱导。PM对映异构体通过手性HPLC色谱柱完全分离。体内研究发现，暴露于250 ng L（-1）PM外消旋体及其对映异构体7天足以刺激vtg1，esralpha和cyp19b表达，而暴露于1000 ng L（-1）则显着诱导基因表达。除vtg2外，其他均类似于对照（50 ng L（-1）E2）。在雌激素反应性基因表达的诱导中，在对映异构体之间检测到显着差异。在1000 ng L（-1）的暴露水平下，对（-）-反式对映异构体的vtg1，esralpha和cyp19b响应分别比用ET处理的组高约3.2-，1.8-和1.5倍。 （+）-反式对映异构体（p <0.05）。在两个顺式对映体治疗组中，（+）-顺式使cyp19b基因的mRNA水平比（-）-顺式对映体高约1.5倍。在四种对映异构体中，（-）-反式对映异构体显示出最大的雌激素活性。结果强烈表明暴露于幼虫斑马鱼的PM对映体的雌激素活性中存在显着的对映选择性。这些发现增加了关于毒性中对映选择性的越来越多的证据，