Mass spectrometric analysis of the perisympathetic organs in locusts: identification of novel periviscerokinins.

A mass spectrometric analysis carried out to determine the peptidome of the abdominal perisympathetic organs in the locust species Locusta migratoria and Schistocerca gregaria yielded a number of predominant ion peaks, among which are Lom-PVK (AAGLFQFPRVamide) and Scg-MT-2 (TSSLFPHPRLamide). In addition, three novel peptides were identified: Lom-PVK-2 (identical in Schistocerca): GLLAFPRVamide, Lom-PVK-3: DGGEPAAPLWFGPRVamide, and Scg-PVK-3: DGAETPGAAASLWFGPRVamide. An extensive mass spectrometric study of the central nervous system showed that the periviscerokinins (-PRVamides) and Scg-MT-2 (-FXXPRLamide) are restricted to the abdominal ganglia and their perisympathetic organs, while the pyrokinins (-FXPRLamides) are present only in the brain-retrocerebral complex. Sequence comparison with the Drosophila genes supports a conserved gene structure whereby a capability-like gene encodes the periviscerokinins that are expressed in the abdominal ganglia and stored in the perisympathetic organs, while a hugin-like gene encodes the pyrokinins that are expressed in the head ganglia and stored in the retrocerebral complex.