Zhang Yinjun, Zhang Yi, Chen An, Zhang Wei, Chen Hao, Zhang Quan
College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, China.
Affiliated High School to Hangzhou Normal University, Hangzhou, China.
Chirality. 2016 Jun;28(6):489-94. doi: 10.1002/chir.22605. Epub 2016 Apr 22.
Enantioselectivity of chiral pesticides in environmental safety has attracted more and more attention. In this study, we evaluated the enantioselective toxicity of rac-metalaxyl and R-metalaxyl to zebrafish (Danio rerio) embryos through various malformations including pericardial edema, yolk sac edema, crooked body, and short tails. The results showed that there were significant differences in toxicity to zebrafish embryos caused by rac-metalaxyl and R-metalaxyl, and the LC50 s at 96 h are 416.41 (353.91, 499.29) mg · L(-1) and 320.650 (279.80, 363.46) mg · L(-1) , respectively. In order to explore the possible mechanism of the development defects, the genes involved in the hypothalamic-pituitary-gonadal axis (vtg1, vtg2, cyp17, cyp19a, cyp19b) and hypothalamic-pituitary-thyroid axis (dio1, dio2, nis, tg, tpo) were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). The results revealed that there were no significant differences in the expression of vtg1, vtg2, cyp17, cyp19a, and cyp19b after exposure to rac-metalaxyl. However, the expression of vtg1, cyp19a, and cyp19b decreased significantly after exposure to R-metalaxyl. And likewise, rac-metalaxyl only caused the upregulation of dio2, while R-metalaxyl suppressed the expression of dio1 and tpo and induced the expression of dio2 and nis. The change of gene expression may cause the enantioselectivity in developmental toxicity in zebrafish embryo. The data provided here will be helpful for us to comprehensively understand the potential ecological risks of the currently used chiral fungicides. Chirality 28:489-494, 2016. © 2016 Wiley Periodicals, Inc.
手性农药在环境安全性方面的对映体选择性已引起越来越多的关注。在本研究中，我们通过心包水肿、卵黄囊水肿、身体弯曲和短尾等各种畸形情况，评估了消旋甲霜灵和R - 甲霜灵对斑马鱼（Danio rerio）胚胎的对映体选择性毒性。结果表明，消旋甲霜灵和R - 甲霜灵对斑马鱼胚胎的毒性存在显著差异，96小时的半数致死浓度（LC50）分别为416.41（353.91，499.29）mg·L⁻¹和320.650（279.80，363.46）mg·L⁻¹。为了探究发育缺陷的可能机制，通过实时定量聚合酶链反应（qRT - PCR）对下丘脑 - 垂体 - 性腺轴（vtg1、vtg2、cyp17、cyp19a、cyp19b）和下丘脑 - 垂体 - 甲状腺轴（dio1、dio2、nis、tg、tpo）中涉及的基因进行了定量分析。结果显示，暴露于消旋甲霜灵后，vtg1、vtg2、cyp17、cyp19a和cyp19b的表达没有显著差异。然而，暴露于R - 甲霜灵后，vtg1、cyp19a和cyp19b的表达显著下降。同样，消旋甲霜灵仅导致dio2的上调，而R - 甲霜灵抑制了dio1和tpo的表达并诱导了dio2和nis的表达。基因表达的变化可能导致斑马鱼胚胎发育毒性中的对映体选择性。此处提供的数据将有助于我们全面了解当前使用的手性杀菌剂的潜在生态风险。《手性》28:489 - 494，2016年。©2016威利期刊公司
