Zhejiang University, Hangzhou, Zhejiang, Peoples Republic of China.
Environ Toxicol Chem. 2011 Jul;30(7):1576-81. doi: 10.1002/etc.549. Epub 2011 May 7.
Clodinafop-propargyl, an aryloxyphenoxypropionate herbicide, is widely used for the control of annual grasses. However, research focusing on the ecotoxicity of this herbicide is limited. The present study employed zebrafish (Danio rerio) as a model to investigate its developmental toxicity. Embryos were exposed to a range of concentrations from 0.2 µM to 5 µM starting at late cleavage stage (2 h postfertilization, [hpf]) or late gastrulation stage (10 hpf). The results showed that the two exposure strategies had the same minimum teratogenic concentration of 0.6 µM but caused different groups of morphogenetic malformations. When exposure was initiated at 2 hpf, clodinafop-propargyl caused various embryonic phenotypes, including embryos with a fin gap in the ventral tail and embryos with coiled tail. When exposure was initiated at 10 hpf, clodinafop-propargyl resulted in failure of the tail to detach, in which the ventral tissues failed to grow out but instead adhered to the yolk extension, and the defect differed to various degrees among embryos. Similar effects were observed for embryos exposed to clodinafop, the metabolite of clodinafop-propargyl. Because these defects were mainly confined to the posterior and ventral region that derived from ventral blastoderm cells, we have evaluated the expression of the ventral mesoderm marker gene gata-1 and ventral ectoderm marker gene gata-3. No significant alteration was seen in gata-1 expression except for the expanded blood islands, whereas the expression of gata-3 was significantly reduced. Our findings showed that clodinafop-propargyl exposure disturbed embryonic patterning and fate specification of ventrally derived gastrula ectoderm cells.
精吡氟禾草灵，一种芳氧苯氧丙酸类除草剂，被广泛用于防治一年生禾本科杂草。然而，关于该除草剂的生态毒性的研究有限。本研究采用斑马鱼（Danio rerio）作为模型，研究其发育毒性。胚胎从晚期裂期（受精后 2 小时，[hpf]）或晚期原肠胚期（10 hpf）开始，暴露于从 0.2 μM 到 5 μM 的一系列浓度中。结果表明，两种暴露策略具有相同的最低致畸浓度 0.6 μM，但引起了不同的形态畸形组。当在 2 hpf 时开始暴露，精吡氟禾草灵引起各种胚胎表型，包括腹部尾部鳍裂的胚胎和尾部卷曲的胚胎。当在 10 hpf 时开始暴露，精吡氟禾草灵导致尾巴无法脱落，其中腹部组织无法向外生长，而是粘附在卵黄延伸上，并且缺陷在胚胎之间存在不同程度的差异。暴露于精吡氟禾草灵的胚胎也观察到了类似的效果，精吡氟禾草灵是精吡氟禾草灵的代谢物。由于这些缺陷主要局限于源自腹侧胚盘细胞的后腹部区域，我们评估了腹侧中胚层标记基因 gata-1 和腹侧外胚层标记基因 gata-3 的表达。除了扩大的血岛外，gata-1 的表达没有明显改变，而 gata-3 的表达显著降低。我们的研究结果表明，精吡氟禾草灵暴露干扰了腹侧原肠胚外胚层细胞的胚胎模式形成和命运特化。
