earticle

영어

Toxicity of two common pesticides (e.g., glyphosate and methidathion) and their impacts on the gene expression in non-target organisms were studied in this work using a water flea, Daphnia magna. Particularly, we investigated both the acute (24h) and chronic (21d) effects of these chemicals on physiological responses such as viability, growth, and reproduction as well as molecular responses such as gene expression in D. magna. Through RT-PCR, the expression of five genes selected as representative biomarkers including Arnt, Vtg, CYP4, CYP314 and Dhb was analyzed in D. magna exposed to glyphosate and methidathion. Our results showed that the expression of these genes in D. magna were significantly down-regulated in response to the LC5, LC10, LC20, and LC50 concentrations of pesticides for short-time (24h) exposure. Among five examined genes, Cyp4 and Cyp314 genes, expressed differently in exposure of glyphosate and methidathion, respectively. This revealed that these two genes could be considered as potential biomarkers for the acute toxicity of glyphosate and methidathion. Interestingly, expression of these five genes in D. magna tended to increase when culturing neonates in the medium fed with some low concentrations (e.g., 1/10, 1/50, and 1/100 LC50) of both pesticides for a long-time (21d) experiment. Therefore, this finding suggested that the acute toxicity of glyphosate and methidathion may cause some damages on the DNA function in D. magna which lead to the decrease of expression level of the five selected genes while the chronic toxicity of these chemicals may stimulate some acclimation mechanism to help organisms to overcome the adverse impacts from the toxic environments.