Ecological and Evolutionary Genetics of P450 Genes in DesertDrosophila

福格曼9806888 细胞色素P450基因产生酶，使昆虫能够耐受有毒化学物质，如杀虫剂和某些植物化合物。一些植物通过制造对试图以它们为食的动物有毒的化学化合物来保护自己免受昆虫（和其他食草动物）的侵害。 细胞色素P450酶通常通过改变化学结构来解毒化合物。因此，对P450基因的研究将为昆虫如何对杀虫剂和/或植物防御化学品产生抗性提供信息。 该建议涉及使用昆虫-植物模型系统。昆虫是果蝇属的果蝇，植物是生长在美国西南部和墨西哥的索诺兰沙漠的柱状仙人掌。已经获得了关于该模型系统的大量背景信息，包括关于果蝇的生态学和遗传学的数据以及仙人掌产生的有毒化学物质的鉴定和表征。利用现代分子遗传学技术，以前的实验已经从适应沙漠的果蝇中分离出100多个P450基因。由于在每种昆虫中存在多个P450基因，因此最重要且目前未回答的问题之一是单个P450基因对抗性的相对贡献是什么？本提案中的实验将研究这个问题，并将大大有助于我们理解昆虫进化P450介导的抗性的机制。 这一目标代表了昆虫生态遗传学和进化领域的重大进展。

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.