Effect of heavy metals on the antioxidant enzymes in the marine ciliate Euplotes crassus

• DOI: 10.1007/s13530-011-0103-4
• Publication Date: 2012-01-20T19:16:17Z
• Authors: Se-Hun Kim; Mi-Young Jung; Young-Mi Lee
• Keywords: 0301 basic medicine; 03 medical and health sciences; 13. Climate action; 14. Life underwater

A single-cell eukaryote, Euplotes crassus is considered as a suitable model species to evaluate the effect of environmental contaminants particularly in sedimentary aquatic environments. Here, we investigated the effect of heavy metals (Cu, Pb and Zn) on the population growth and the gene expression of antioxidant enzyme coding genes (Ec-GR, Ec-GPx, and Ec-GSTtheta) in E. crassus. As a result, heavy metals negatively affected population growth measured as the 48-h EC50 values as 1.58 mg/L for Cu, 4.13 mg/L for Pb, and 4.97 mg/L for Zn. Copper and zinc significantly increased the expression of Ec-GR, Ec-GPx, and Ec-GST-theta, suggesting that these genes may be involved in protection mechanisms against oxidative stress induced by Cu and Zn. Interestingly, Pb exposure inhibited the expression of all genes, indicating that these genes may be effective molecular biomarkers to evaluate toxic effects of heavy metals in this species.