Effect of ammonia on the gene expression levels of the freshwater cyclopoid Eucyclops serrulatus

Ammonia pollution is a critical issue in Europe, since more than half of the European freshwater bodies actually fail to meet EU quality standards for this chemical. In this study, the response of stress-related genes to a sublethal ammonia concentration has been investigated in the adults of the freshwater cyclopoid Eucyclops serrulatus. Two short-term exposures (12 h and 24 h) at 12 mg/L NH4+ have been tested. Results indicate that 12 mg/L NH4+ causes a significant increase in the expression of some proteins, namely CAT, HSP90 and HSP40, suggesting an activation of the protecting antioxidant system after both 12 h and 24 h.