Deformed expression in the Drosophila central nervous system is controlled by an autoactivated intronic enhancer

esophageal ganglion of the embryonic central nervous system. This Neural autoregulatory enhancer (NAE) maps in the large Dfd intron just upstream of the homeobox exon and requires Dfd protein function for its full activity. A 608 bp NAE subfragment retains regulatory function that is principally localized in the subesophageal ganglion. This small region of the Drosophila melanogaster genome contains numerous blocks of sequence conservation with a comparable region from the Dfd locus of D.hydei. A pair of conserved blocks of NAE sequence match a Dfd protein binding site in the epidermal autoregulatory element, while another conserved sequence motif is repeated multiple times within the 608 bp subelement.