PBAN-like immunoreactivity has been detected in the suboesophageal
ganglion and the brain (Br-SOG) of larvae and adult males and females of Agrotis ipsilon, using an antiserum against Helicoverpa zea PBAN (
Hez-PBAN). The amino acid sequence of A. ipsilon PBAN (Agi-PBAN) was deduced from the
cDNA sequence, using both
Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and 5' Rapid Amplification of
cDNA Ends (RACE). The primers were degenerate sets of
oligonucleotides derived from known amino acid sequences of the PBAN precursor. The final cloned fragment contained the complete DNA sequence coding for the putative Agi-PBAN. Based on a comparison with known PBAN processing from the
polypeptide precursor, we propose that Agi-PBAN is a 33-amino
acid peptide. Agi-PBAN exhibits high sequence homology with
Hez-PBAN (88%), Lymantria dispar PBAN (
Lyd-PBAN, 88%) and Bombyx mori PBAN (Bom-PBAN, 73%). Agi-PBAN shares the C-terminal hexapeptide sequence (Tyr-Phe-Ser-Pro-Arg-LeuNH2) with all identified PBANs but has only one
methionine residue instead of two in
Hez-PBAN and
Lyd-PBAN, and three in Bom-PBAN. Based on predicted a.a. sequence, Agi-PBAN, with Leu-NH2 as C-terminal motif, has been synthesized and assayed for its ability to promote
pheromone production in decapitated females of A. ipsilon. Synthetic Agi-PBAN induced
pheromone production in decapitated females as evaluated by the male responsiveness to the pheromonal blend in a wind tunnel.