cytochrome P450-mediated metabolic resistance to insecticeds in the house fly, Musca domestica

摘要

The topic of my presentation at the Meeting of the Japanese Society for Bioscience, Biotechnology, and Agrochemistry was a general overview of P450 enzymes in insects, covering diversity, functional expression, regulation, and inhibition. Because a recent review covers these general aspects, I will present here a more focused discussion of the role of mutations that affect P450 regulation and cause metabolic resistance to insecticides. One of the major reasons why insect cytochrome P450 enzymes are studied is because they are responsible for so many cases of metabolic resistance, and therefore cause so many problems in the control of insect pests of agriculture and insect vectors of disease. Elucidation of the mechanisms of resistance is crucial for resistance management. Practical tools for resistance monitoring may need to distinguish between different resistance mechanisms, for instance when survival (easily scored) or increased metabolism (sometimes easily scored, e.g., synergists), can be caused by any of three underlying causes (amplification of the gene for the detoxification enzyme, point mutation making it a more efficient enzyme, overexpression of the enzyme by mutation of a regulatory pathway). Failure to distinguish these molecular mechanisms may lead to an underestimation of the number of genes and mutations involved, as well as a lack of insight into the dynamics of spread of such mutations.