The establishment and maintenance of embryonic determination and differential patterns of gene expression is essential for normal animal development. In Drosophila embryonic determination is, at least in part, under the control of the selector genes of the bithorax and Antennapedia complexes. I have been studying a genetic region, referred to as the PAS-R, that contains a number of related genes. The proper function of these genes is essential for normal development and it appears to be required for the proper regulation of selector genes. This proposal consists of a molecular and developmental genetic analysis of the PAS-R. I propose to use classical genetics, in vitro mutagenesis, and germ line transformation to rigorously identify individual proteins and RNAs with functional genes. I will sequence cDNA clones derived from these genes to determine the amino acid sequences of the proteins they encode. This may tell us something about their function, and is valuable information for making antibody probes for the proteins. I propose to use both developmental and molecular approaches to identify genes whose regulation requires the presence of PAS-R gene products. Experimental systems will be developed that will enable us to study this regulation, and to identify functional domains of PAS-R proteins and target recognition sequences. The orchestration of gene expression which results in the development of an adult is still largely not understood. Insight into the function of genes such as those found in the PAS-R region which are thought to regulate the expression of genes known to be developmentally essential should result from this study.
