Physiological Evolution and Microarray Analysis in Stress-Selected Drosophila

University Of Arizona, Tucson AZ

Investigators

Abstract

The proposed research will use the fruitfly, Drosophila melanogaster, as a model system for the evolution of water balance in insects. A total of 27 populations, derived from three collection sites, will be studied. Nine populations will be selected for resistance to desiccation stress, and 18 will serve as controls for the selection treatment. Physiological characters associated with desiccation resistance (water content, water loss, metabolic rate, activity) will be assayed at intervals of ten generations. Genetic differences between populations will be investigated using DNA microarrays (gene chips). Genes that are turned on or off in response to water stress will be identified, as well as other genes that contribute to desiccation resistance. By integrating physiological and genetic studies, it will be possible to relate specific changes in gene expression to physiological mechanisms of desiccation resistance. These experiments will also be used to identify new physiological mechanisms by identifying novel genes that respond to selection, and thereby to learn more about how insects and other organisms respond to environmental stress.