Proteomic analysis of Daphnia magna exposed to glyphosate and methidathion

Proteomic analysis was performed to identify proteins involved in the stress responses of Daphnia magna to glyphosate and methidathion. Lethal concentration of chemicals causing 50% mortality (LC50) determined by acute toxicity assays were used to expose to daphnias from 24 h to 21 days prior to total protein extraction. The proteomic profile of tested organisms was analyzed by the two-dimensional electrophoresis method. The average intensity of each spots was then analyzed to determine the differently expressed proteins (DEPs). The DEPs was considered as down- or up-regulations only if their expression level in control samples are linearly higher than LC50 or lower than LC50, respectively. The result showed that there are 22 and 27 DEPs responding to the exposure of glyphosate and methidathion, respectively. The expression pattern of established DEPs is helpful to understand the molecular response of D. magna to glyphosate and methidathion, and discover potential candidates as novel biomarkers.