Conserved sequence block clustering and flanking inter-cluster flexibility delineate enhancers that regulate nerfin-1 expression during Drosophila CNS development.

We have identified clusters of conserved sequences constituting discrete modular enhancers within the Drosophilanerfin-1 locus. nerfin-1 encodes a Zn-finger transcription factor that directs pioneer interneuron axon guidance. nerfin-1 mRNA is detected in many early delaminating neuroblasts, ganglion mother cells and transiently in nascent neurons.