Sanjay Kumar

Alphamethrin is an important type II pyrethroid, a cyano-derivative that exhibits toxic response in the mutants of Drosophila melanogaster which has been adjudged on the basis of LC50 values. The concentrations to assess LC50 value of alphamethrin were the same for double mutants (sepia ebony and sepia vestigial) and single mutants (ebony, sepia, vestigial). Double mutant (sepia vestigial) have been adjudged most resistant whereas single mutant (sepia), the most susceptible. The observed difference in LC50 among single and double mutants are due to some genetic consequences which include single chromosome with mutation on one arm, two chromosome with mutation on both the arms, distance of mutation site from centromere, nucleotide bases, pigmentation, wing pattern and rate of mutation, effect of pesticide toxicity on cell survival and metabolism.

Type II Pyrethroid exhibited its potential against transgenic forms of Drosophila melanogaster. The intrastrain crosses and respective observations with regard to genetic expression on the imaginal disc have revealed the potentiality of the experimental compound alphamethrin on both transgenic flies, wingless lac Z and engrailed lac Z . The reduction in wing size in both the forms (wingless lac Z and engrailed lac Z) is also an outcome of engrailed gene which acts as a pleotropic gene governing different functions in different parts of Drosophila. The differential expression of gene in the two transgenic forms reflect differential interaction in terms of reduced response of pyrethroid with the concerned gene.