Mapping the binding regions of the cubitus interruptus (Ci) repressor form

Paracrine Hedgehog (Hh) signaling regulates growth and patterning in many Drosophila organs. We mapped chromatin binding sites for Cubitus interruptus (Ci), the transcription factor that mediates outputs of Hh signal transduction, and we analyzed transcription profiles of control and mutant embryos to identify genes that are regulated by Hh. Putative targets we identified include several Hh pathway components, most previously identified targets, and many targets that are novel. Analysis of expression patterns of pathway components and target genes gave evidence of autocrine Hh signaling in the optic primordium of the embryo. And, every Hh target we analyzed that is not a pathway component appeared to be regulated by Hh in a tissue-specific manner. We present evidence that Hh-dependent tissue specificity is dependent upon transcription factors that are Hh-independent, suggesting that “pre-patterns” of transcription factors partner with Ci to make Hh-dependent gene expression position-specific. We utilized the DamID method to identify regions of CiRep methylated genomic DNA in stage 10-11 Drosophila embryos. Comparison of DamCiRep directed methylation vs. Dam Alone background methylation using 3 replicate experiments.