| A large number of studies indicated that the effects of pollutants,including pesticides,on the water environment and aquatic animals could not be ignored.Propamocarb(PM)is a broad-spectrum systemic fungicide that has been widely used to prevent and treat diseases caused by fungi in various fresh fruits and vegetables such as cucumbers,strawberries,flowers,and lawns.Some existing studies had shown that PM had certain toxicological effects.For example,the effects of PM on gut microbiota e and glucose,lipid metabolism in mice had been confirmed.However,the toxicological effects of PM on aquatic animal zebrafish still remain unclear.In this study,different concentrations of PM were used to expose zebrafish embryos and adult fish,effects on development and lipid metabolism were aanylzed.In order to clarify the developmental toxicity of PM on zebrafish embryos,some physiological indicators such as hatching rate of zebrafish larval was tested.It was found that PM exposure could cause delayed zebrafish embryo hatching,abnormal heart rate,disturbed heart development and significant changes in key indicators related to oxidative stress.For example,the enzyme activities of CAT and GPX increased significantly in the high concentration PM exposure group.All these results indicated that PM exposure could lead to abnormal development and oxidative damage in zebrafish embryos.Then,in order to study the neurotoxic effects of PM on zebrafish larval,the swimming behavior and neurodevelopment of zebrafish larval after PM exposure were examined.The results showed that the free swimming distance and speed of zebrafish larval after PM exposure were both affected,and significantly inhibited acetylcholinesterase(Ach E)activity and dopamine(DA)levels in zebrafish larval.At the same time,we also observed that the transcriptional levels of genes related to neurodevelopment Elavl3,Mbp,Shha,Gfap,Gap43,etc changed significantly after PM exposure.These results indicated that PM exposure could severely affect development and locomotor behavior of zebrafish larval.Finally,in order to study the toxic effects of PM on hepatic metabolism and gut microbiota of adult zebrafish,their metabolic profiles and microbiota composition were analyzed.The results showed that PM exposure caused significant changes in hepatic metabolites,leading to significant changes in 48 metabolites,22 of which increased and 26 decreased,and these changed metabolites were involved in glycolysis and lipid metabolism biochemical processes.In addition,by combining the results of 16 S r RNA gene V3-V4 region high-throughput sequencing with fluorescent quantitative PCR,it was found that among the zebrafish gut microbiota,the abundance of the main flora of Proteobacteria,Bacteroidetes and Firmicutes has significantly changed in the PM treated group.At the same time,the abundance and diversity of some gut microorganisms at the "genus" level have also changed.These results indicated that PM exposure could cause hepatic metabolism disorders,and this may be related to gut microbiota dysbiosis in adult zebrafish.In summary,the results of this study indicated that PM exposure not only caused embryonic developmental toxicity,neurotoxic effects and oxidative stress in zebrafish larval,but also induced hepatic metabolic disorders and gut microbiota dysbiosis in adult zebrafish.The results could provide support for the evaluation of PM toxicity to aquatic organisms. |
PDF Full Text Request