Combined Developmental Toxicity Of Cyhalofop-butyl And Quizalofop-p-ethyl On The Zebrafish (Danio rerio) Embryos

Aryloxyphenoxypropionate herbicides have the characteristics of high efficiency, low toxicity, and safety to subsequent crops, and occupy an important position in the world herbicide market. Cyhalofop-butyl and quizalofop-p-ethyl are two representative herbicides, which are widely used in weed control. However, there is limited information on their combined toxicity to aquatic organisms. In this study, the developmental toxicity of cyhalofop-butyl and quizalofop-p-ethyl exposure in combination on zebrafish embryos was valuated to better understand the interaction between the that. The 96 h-LC50 (50% lethal concentration) of cyhalofop-butyl and quizalofop-p-ethyl on zebrafish embryos were 0.637 mg{middle dot}L-1 and 0.248 mg{middle dot}L-1, respectively. The combined effect of cyhalofop-butyl and quizalofop-p-ethyl was an antagonistic effect, and the 96 h-LC50 of zebrafish embryos was 1.043 mg{middle dot}L-1. Morphologically distinct pericardial edema and yolk cysts were observed after combined exposure, with significant effects on body length and heart rate in zebrafish embryos. At the same time, the mRNA levels of gene related to apoptosis and cardiac development also changed significantly. Therefore, we speculate that changes in genes related to apoptosis and cardiac development should be responsible for the abnormal development during embryonic development following co-exposure of cyhalofop-butyl and quizalofop-p-ethyl. HighlightsO_LICombined exposure caused deformities in zebrafish. C_LIO_LICombined exposure caused apoptosis in zebrafish. C_LIO_LICombined exposure altered the expression of apoptosis and cardiac-related genes in zebrafish. C_LI