The objective of this program is to analyze problems related to neoplasia using the fruit fly Drosophila. Although this is a rather unconventional organism in cancer research, the abundance of genetic variations and the availability of methods for genetic manipulation make possible a number of unusual approaches to the cancer problem. In one series of experiments, we are analyzing genetically induced neoplasia by the isolation and use of temperature-sensitive mutations causing neoplastic changes. Such mutations may make it possible to control the onset and reversion of neoplasia so that these transitions can be studied in detail. We are also using cell dissociation and reaggregation to study the interactions between normal and neoplastic cells. A second goal is to document the occurrence of genetic transformation by DNA microinjection in Drosophila. We are injecting molecular clones of the wild-type alcohol dehydrogenase gene into mutant animals, and screening for genetic alterations. We propose to use genetic transformation to examine the interactions of exogenous DNA with chromosomal DNA, and to develop a bioassay for the study of developmentally important genes.