Pyrokinin/PBAN-like peptides in the central nervous system of Drosophila melanogaster

The pyrokinin/pheromone biosynthesis activating neuropeptide (PBAN) family of peptides found in insects is characterized by a 5-amino-acid C-terminal sequence, FXPRLamide. The pentapeptide is the active core required for dive rse physiological functions, including stimulation of pheromone biosynthesi s in female moths, stimulation of muscle contraction, induction of embryoni c diapause in Bombyx mori, and stimulation of melanization in some larval m oths. Recently, this family of peptides has been implicated in accelerating the formation of the puparium in a dipteran. Using bioassay and immunocyto chemical techniques, we demonstrate the presence of pyrokinin/PBAN-like pep tides in the central nervous system of Drosophila melanogaster. Pheromonotr opic activity was shown in the moths Helicoverpa zea and Helicoverpa armige ra by using dissected larval nervous systems and adult heads and bodies of D. melanogaster. Polyclonal antisera against the C-terminal ending of PBAN revealed the location of cell bodies and axons in the central nervous syste ms of larval and adult flies. Immunoreactive material was detected in at le ast three groups of neurons in the subesophageal ganglion of 3rd instar lar vae, pupae, and adults. The ring gland of both larvae and adults contained immunoreactivity. Adult brain-subesophageal ganglion complex possessed addi tional neurons. The fused ventral ganglia of both larvae and adults contain ed three pairs of neurons that sent their axons to a neurohemal organ conne cted to the abdominal nervous system. These results indicate that the D. me lanogaster nervous system contains pyrokinin/PBAN-like peptides and that th ese peptides could be released into the hemolymph.