Isolation and characterization of a Drosophila gene that encodes multiple neuropeptides related to Phe-Met-Arg-Phe-NH₂ (FMRFamide)

A Drosophila gene that encodes neuropeptides related to molluscan Phe-Met-Arg-Phe-NH₂ (FMRFamide) was isolated by screening a genomic library with a fragment of an Aplysia Phe-Met-Arg-Phe-NH₂ cDNA and with synthetic oligonucleotides. This gene was used to isolate a cDNA from a Drosophila adult head cDNA library. The cDNA was defined by sequence analysis to encode 13 peptides that have Phe-Met-Arg-Phe-NH₂ or related sequences at their carboxyl termini. Other putative neuropeptides, including one that has homology to mammalian corticotropin-releasing factor, are present in the deduced ~39-kDa precursor. Southern blot analysis suggested the presence of a single Phe-Met-Arg-Phe-NH₂-like gene within the haploid genome. RNA blot analysis indicated the expression of at least two transcripts of ~1.7 and ~0.7 kilobases. Both transcripts are evident throughout larval, pupal, and adult developmental stages. In situ hybridization was used to localize this neuropeptide gene to band 46C on the right arm of the 2nd chromosome. These data provide the basis for utilizing the advanced genetics and molecular techniques of Drosophila to address complex aspects of neuropeptide expression and function.