Biochemical genetics of insecticide resistance in house fly, Musca domestica L

Abstract

A triple mutant strain of the house fly, Misca domestica L., with 3 visible recessive genes, ar, stw, and car, on chromosome II was developed. With this strain, genetic tests were made to determine the order and map positions of those 3 genes as well as to locate the genes for insecticide resistance in relation to those mutants in 5 resistant strains. The gene order found in the results of all experiments was R-ar-stw-car. The R gene appeared to be at the same locus in all strains tested, regardless of the biochemistry of the particular strain involved. This suggested a common gene for all the strains tested in this experiment, most probably a regulatory gene. Significant difference in some map positions of the genes tested were observed between the organophosphate-resistant (OP) and -susceptible strains. Suppressions of crossing over between the ar and stw genes occurred consistently in the OP-resistant strains. Chromosome inversions were suggested to explain this phenomenon. A series of additional experiments was performed to obtain further understanding of these results. The outcome not only confirmed the previous results, but also showed that position effect might play a very important role in insecticide resistance in the strains tested.