Malathion Prompted Genotoxicity Assessment in rDNA ITS1 and ITS2 Sequence ofAnopheles stephensi

Indiscriminate use of pesticides in agricultural practices has developed its toxicity in humans and animals exposed to it. Malathion is a non-systemic insecticide belonging to organophosphate class. It is used in controlling Mediterranean flies, bugs, and aphids in fields. The present study was aimed to evaluate the malathion induced genotoxicity in Internal transcribed spacer, ITS 1 and 2 sequences of rDNA of mosquito, Anopheles stephensi. For this, second instar larvae of mosquito were exposed to 2.54 ppm (LC20) of malathion for an acute period of 24h. Post-treatment, larvae were allowed to develop into adults, and Internal transcribed spacer (ITS) sequences of rDNA were amplified by Polymerase chain reaction (PCR). PCR amplification revealed significant point mutations in form of transition, transversion, deletion and insertion in treated ITS 1 and 2 sequences compared to control. ITS 1 sequence showed deletion of 26 bases, insertion of 141 bases, and substitutions of 236 bases compared to control. While, treated ITS 2 sequence suffered 48 deletions, 54 insertions, and 117 substitutions of nucleotide compared to non-treated mosquito sequences. ITS 1 was found to be more affected by malathion toxicity with lowered GC content. Thus, present study details the toxicity of pesticide in the mosquito, Anopheles stephensi, contributing to the field of toxicology.