Organophosphorus and
carbamate are widely used in agricultural production. Caenorhabditis elegans is a model organism that is widely used in various toxicology studies. To understand the effects of two types of commonly used pesticides,
phoxim (organophosphorus) and
carbaryl (
carbamate), we determined the activities of acetylcholinesterases (
AChEs) and detected the expression of four ace genes by RT-qPCR in C. elegans following treatment with these pesticides. The results showed that
phoxim and
carbaryl could reduce
acetylcholinesterase activities and up-regulate the ace-3
mRNA expression levels. We also detected the toxic effects of these pesticides on the ace-3 deletion mutant dc-2, and found that some characteristics, including LC50, development, movement, reproduction and lifespan, were reduced in the dc-2 mutant. However, the toxic effects of
carbaryl were weaker than those of
phoxim.
Carbaryl treatment did not significantly affect the LC50, movement ability or lifespan. Interestingly, body and brood size increased with
carbaryl treatment at low concentrations. These data showed that both
phoxim and
carbaryl could inhibit AChE but that the ace-3 was necessary for
phoxim detoxification. The LC50 of
phoxim and
carbaryl in wild type N2 and the ace-3 deletion mutant dc-2. **Higher significant differences (P < 0.01).