Identifying target genes of signaling pathways that operate during embryogenesis is an important step toward understanding how signals govern morphogenesis. I propose to search for targets of Hedgehog signaling in the hope of understanding how Hedgehog controls the formation of segment boundaries in Drosophila embryos. I will also pay attention to Hedgehog targets that might be involved in Wingless degradation, another interest of my host lab. I will apply the degron technology to construct a temperature sensitive allele of cubitus interuptus an essential effector of Hh signaling. RNA extraction after temperature shifts and hybridization onto micro arrays will allow me to uncover manges in transcriptional profile caused by loss of cubitus interuptus function and hence identify physiological target genes that operate at different stages. If the degron method cannot be applied to Drosophila, I will use the inducible expression of two forms of cubitus interuptus (a constitutive repressor and a constitutive activator) to identify targets. In site hybridization will be used to confirm candidate targets and subsequent functional analysis will assess the cell biological function of confirmed targets.