Molecular Signatures of Reduced Nerve Toxicity by CeCl 3 in Phoxim-exposed Silkworm Brains

CeCl 3 can reduce the damage caused by OP pesticides, in this study we used the brain of silkworms to investigate the mechanism of CeCl 3 effects on pesticide resistance. The results showed that phoxim treatments led to brain damages, swelling and death of neurons, chromatin condensation and mitochondrial damage. Normal nerve conduction was severely affected by phoxim treatments, as revealed by: increases in the contents of neurotransmitters Glu, NO and ACh by 63.65%, 61.14% and 98.54%, respectively; decreases in the contents of 5-HT and DA by 53.19% and 43.71%, respectively; reductions in the activities of Na + /K + -ATPase, Ca 2+ /Mg 2+ -ATPase and AChE by 85.27%, 85.63% and 85.63%, respectively; and increase in the activity of TNOS by 22.33%. CeCl 3 pretreatment can significantly reduce such damages. Results of DGE and qRT-PCR indicated that CeCl 3 treatments significantly upregulated the expression levels of CYP4G 23, cyt-b 5, GSTs-σ 1, ace 1, esterase-FE 4 and β-esterase 2. Overall, phoxim treatments cause nerve tissue lesions, neuron death and nerve conduction hindrance, but CeCl 3 pretreatments can promote the expression of phoxim resistance-related genes in silkworm brains to reduce phoxim-induced damages. Our study provides a potential new method to improve the resistance of silkworms against OP pesticides.