9528392 Body size of animals is controlled by adjustments in cell size and cell number. We know relatively little about mechanisms that regulate cell size and cell division to yield an animal of a particular size. This research seeks to understand the relative importance of changes in cell size and cell number during evolutionary changes in body size, and to identify the genes that control such changes. It will focus on Drosophila because they exhibit a wide range of sizes and because of the extensive data that exist on their genetics and developmental biology. Measurements of cell size and number during development of imaginal discs will identify the developmental steps that lead to changes in body size. A comparative analysis will identify the pattern of evolution of body size differences, and a hybridization study will seek to map the genes that control body size. The results will increase our understanding of the factors that control body size, and the mechanisms that lead to changes in cell size and body size of animals.
