Characterization of PBAN and PBAN-encoding gene neuropeptides in the central nervous system of the corn earworm moth, Helicoverpa zea

Abstract

Both female and male adult corn earworm moths, Helicoverpa zea, were utilized to demonstrate, by immunochemical techniques, the presence and localization of the pheromone biosynthesis activating neuropeptide (Hez-PBAN). A polyclonal antibody was used and was shown to be specific to the C-terminal end of Hez-PBAN. Several other peptides with a similar five amino acid C-terminal ending also cross-reacted in competitive enzyme-linked immunosorbent assays (ELISAs). Immunocytochemical methods determined that in both adult male and female moths immunoreactive material was found in three clusters of cells in the subesophageal ganglion (SEG) and that axons projected from these cell bodies to the corpora cardiaca (CC) and down the ventral nerve cord (VNC). The CC also contained immunoreactive material. Each thoracic and abdominal ganglion also contained a pair of cell bodies with immunoreactivity. In addition, two pairs of axons originating from cell bodies in the SEG extended the entire length of the VNC and terminated in the last abdominal ganglion. ELISAs indicated that the brain-SEG complex contained the highest levels of PBAN-like material followed by the CC and thoracic ganglia respectively. The abdominal ganglia contained low levels of this material. Bioassays of nervous tissue also indicated the same relative levels of PBAN-like material in each part of the nervous system. HPLC fractionation of nervous tissue followed by ELISAs indicated the presence of several other PBAN-related peptides in the brain-SEG complex and CC. The thoracic ganglia had a different profile and contained lower levels of the peptides. These results indicate that male and female adult moths have similar localization of PBAN-related peptides and that the five PBAN-related peptides previously deduced from the gene sequence are probably present in the SEG and CC.