Cell type-specific regulatory sequences control expression of theDrosophila FMRF-NH2 neuropeptide gene

Abstract

The FMRFamide (dFMRFa) neuropeptide gene is expressed in about 17 diverse cell types in the Drosophila central nervous system. This expression pattern is generated by transcriptional control elements that are distributed over 8 kilobases of dFMRFa DNA. Previous studies identified one enhancer within the dFMRFa 5′ region that is both necessary and sufficient to drive reporter transgene expression in one of the 17 dFMRFa cell types, the OL2 neurons. We now report the presence of two additional, non‐overlapping enhancers within the gene: One drives expression by the six Tv neuroendocrine cells, and another in the four X and X2 interneurons. We also show that the Tv neuron‐specific enhancer itself has complex organization, with several positively and negatively acting cis elements. Together, these results describe the organization of what is likely to be a prototypic neuronal gene promoter: an assemblage of multiple, independent, cell type–specific enhancers, each consisting of multiple quantitative elements. © 1999 John Wiley & Sons, Inc. J Neurobiol 38: 507–520, 1999

Functional tests of enhancer conservation between distantly related species

“…A Drosophila ddc::GFP construct containing this fragment was relatively strongly expressed in most pharyngeal muscle cells, a single amphid neuron, a single head interneuron (likely RICL or RIAL) and in PVT, but not in catecholaminergic neurons. Finally, Drosophila FMRF::GFP construct contained a 3.6 kb fragment upstream of the translation initiation site of Drosophila FMRFamide gene which was previously shown to be expressed in nearly all FMRFergic neurons in the fly (Benveniste and Taghert, 1999). We detected consistent expression of this fusion gene in most muscle cells in the pharynx, a single head interneuron (RMDDL, RMDL, RMF, or RMH) and three to five neurons in the ventral cord (DA or VA).…”

Retrograde Gbb signaling through the Bmp type 2 receptor Wishful Thinking regulates systemic FMRFa expression inDrosophila

“…1 (compare A with B), we find that in crawling third instar wit mutants there is a specific disruption in the accumulation of FaRPs in the Tv neurons and the neurohemal organ. Other FaRP-positive cells such as the subesophageal neurons (SE2) (Benveniste and Taghert, 1999) in the ventral ganglia and several neurons in the brain appear to express FaRPs normally or are only moderately affected. It is important to note that the NHO is composed of two components: the two or three NHO cells and the large varicosities formed by the Tv neurons axons that terminate on the NHO cells.…”

“…As the FMRFa gene is known to be strongly expressed in the Tv neurons that innervate the NHO Schneider et al, 1993a;Schneider et al, 1993b), we examined the effect of wit mutations on the expression of a FMRFa/lacZ transgene. The regulatory region of FMRFa comprises several different enhancers, including one that produces strong expression in the Tv neurons (Benveniste and Taghert, 1999). As shown in Fig.…”

“…Although several families are recognized on the basis of conserved sequences, among the most broadly distributed are FMRFamide-related peptides (FaRPs) (Geary et al, 1999;Grimmelikhuijzen et al, 1989;Hinuma et al, 2000;Yang et al, 1985). These peptides share a common C-terminal RFamide sequence and in Drosophila are produced from at least five genes, dromyosuppressin, drosulfakinin, two neuropeptide F-like genes and FMRFa (reviewed by Benveniste and Taghert, 1999;Merte and Nichols, 2002). Some of these loci can produce several different peptides exhibiting unique N-terminal sequences by selective proteolytic processing of a proprotein.…”

The bHLH protein Dimmed controls neuroendocrine cell differentiation inDrosophila

“…The primers 5′-CAGATCTCGACGATTTTTGTTCAGCCAT-3′ (5′ UTR) and 5′-TGCGGCCGCAGAAACTCTCGAAAGGGCT-3′ (end of the ORF) were used to construct a 1236 bp fragment that was cloned into pBSK+ and then transferred to pP{UAST-Myc} at the BglII and NotI sites. Transgenic lines containing P{UAS-dimm::Myc} insertions were created using standard techniques (Benveniste and Taghert, 1999). UAS-dimm::Myc 2-A-3 , Rev8/CyO, Act-GFP flies were crossed to c127-Gal4, UAS-GFP; Rev4/CyO, Act-GFP, and first instar larvae were scored for Act-GFP-and c127-specific GFP labeling patterns.…”