The Drosophila Transcription Network: How Can We Study It? Sequence specific DNA binding proteins regulate development and are the link between cellular physiology and the massive stretches of nonprotein coding DNA in animal genomes. How complex is the regulatory network that these proteins act in? What parameters must be measured so that their action can be modeled? Will it be possible to interpret the transcriptional control information in nonprotein coding DNA? Experiments examining homeoprotein action within the Drosophila network will be described, followed by plans for, and initial results from, a functional genomic attack on the early embryo network.