Characterization of the regulatory elements controlling neuronal expression of the A-isoform of the ecdysone receptor gene of Drosophila melanogaster.

During the development of the adult central nervous system (CNS) of the fruitfly Drosophila melanogaster, the A-isoform of the ecdysone receptor (EcR-A), a typical nuclear hormone receptor, is expressed at high levels in the Type II neurons, a set of neurons that die shortly after the emergence of the adult. To understand the role that transcriptional regulation of nuclear receptor genes plays in CNS development, we have dissected the region controlling the transcription of EcR-A by analyzing the ability of this region to drive the expression of reporter genes in transgenic animals. These analyses have demonstrated that the Type II neurons are a heterogeneous collection of neurons that utilize different regulatory elements to coordinate the expression of the same transcript.