Proteomic Analysis Of Developing Zebrafish Embryo Under Chlorpyrifos Stress

Chlorpyrifos is one of the largest production and sales of organophosphorus pesticide in the world.With the economic development and increasing demands for food, the resistance of pests is increasing rapidly for increase of pesticide residues,which forces farmers to use more pesticides. Meanwhile, some high toxic organophosphate pesticides are prohibited, while chlorpyrifos and other organophosphate pesticides of low toxicity have been widely used. People began to concern human and animal toxicity caused by the chlorpyrifos.Zebrafish ,a new model animal, was used in this paper. We studied the acute toxicity of chlorpyrifos on zebrafish embryos. Phenotype of zebrafish embryos treated by chlorpyrifos showed that: chlorpyrifos can cause a lot of toxicological endpoints, for example, animal pole broken, irregular cell division, curvature of the spine, melanin incompleted, yolk sac disease, egg condensation, no separation of the tail, heart rate decreased, and low hatchability. We also analyzed the hatching rate, heart rate, malformations associated with different chlorpyrifos concentrations. We provided a scientific basis for the rational use of chlorpyrifos.In addition, by means of two-dimensional electrophoresis, mass spectrometry and other proteomic methods to construct zebrafish embryo protein expression profile in different periods. Under the stress of chlorpyrifos (250ppm) , we found 19 differentially expressed proteins of 24hpf zebrafish embryos. These proteins were of significant difference of protein spot and the percentage of volume change more than 2 times,sometimes up to 3 times, according to the T-test (p <0.05).Through matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), we got these specific-expressed protein mass fingerprintings (PMFs). And through the zebrafish protein database, initially identified 4 differential-expressed proteins,3 down-regulated proteins:neuregulin 2b,muscle segment homeobox C,B-cell receptor-associated protein 31,and 1 up-regulated proteins: CSNK1A1L - casein kinase 1, alpha 1-like. We first verified the traditional toxicological mechanism of chlorpyrifos: It can cause significant toxicological effects on the nerves. We also revealed chlorpyrifos can affect cell development and apoptosis, intracellular protein transport, transcriptional regulation, signal transduction,ect. Make us have a better understanding to the toxicology of chlorpyrifos. Besides, zebrafish can also open some phosphorylation-dependent signaling pathway, through self-regulation in response to foreign toxicity invasion.In summary, we have made a comprehensive study on the toxicology of chlorpyrifos at the phenotypic and molecular level, analysed the toxicological mechanism of chlorpyrifos and revealed several new targets for molecular toxicology, The results further uncovered the toxicity of chlorpyrifos metabolic networks, explored the mechanism of toxicity of chlorpyrifos and provided a scientific basis and technical support to reduce the toxicity of chlorpyrifos on the animal and its rational use.