Effects of 2,2-Dichlorovinyl Dimethyl Phosphate (DDVP) on Hsp70 Gene Expression in Rainbow Trout

Abstract

2,2-Dichlorovinyl dimethyl phosphate (DDVP) is used to control insects on crops, household, and stored products, and treat external parasitic infections in farmed fish, livestock, and domestic animals. Ectoparasitic copepods can cause severe skin damage in fish that may lead to death through osmoregulatory failure or infection by opportunistic pathogens. There is considerable uncertainty about whether or not DDVP is implicated in cancer, and the wider environmental con- sequences of its use. In general, and specifically in developing countries and fish farming, less hazardous alternatives are available. The present experiment studied the effects of DDVP at a daily dose of 1.6 mg/l for 21 days on the expression of the heat shock protein (Hsp) 70 gene in rainbow trout (Oncorhynchus mykiss). Hsp70 from control and DDVP-exposed fish was ampli- fied for 20-40 PCR cycling. After the fortieth PCR cycle, the Hsp70 level in mRNA was very low in the control fish and very high in the DDVP-exposed fish, with a statistical difference of p<0.01.