Ecological and Evolutionary Genetics of P450 Genes in DesertDrosophila

点击翻译按钮获取中文摘要

Fogleman 9806888 Cytochrome P450 genes produce enzymes that allow insects to tolerate poisonous chemicals such as insecticides and certain plant compounds. Some plants protect themselves from insects (and other herbivores) by making chemical compounds that are toxic to the animals which try to feed on them. Cytochrome P450 enzymes detoxify chemical compounds, usually by changing their chemical structure. The study of P450 genes, therefore, will provide information as to how insects become resistant to insecticides and/or plant defensive chemicals. This proposal involves the use of an insect-plant model system. The insects are fruit flies of the genus Drosophila, and the plants are columnar cacti which grow in the Sonoran Desert of southwestern United States and Mexico. A wealth of background information on this model system has already been obtained including data on the ecology and genetics of the fruit flies and identification and characterization of the toxic chemicals that the cacti produce. Employing modern techniques of molecular genetics, previous experiments have isolated over 100 P450 genes from desertadapted drosophilids. Since there are multiple P450 genes in each insect species, one of the most important and currently unanswered questions is what is the relative contribution of individual P450 genes to resistance? The experiments included in this proposal will investigate this question and will significantly contribute to our understanding of the mechanisms by which insects evolve P450-mediated resistance. This objective represents a major advancement in the areas of insect ecological genetics and evolution.