Peptidomics of identified neurons demonstrates a highly differentiated expression pattern of FXPRLamides in the neuroendocrine system of an insect.

FXPRLamides are insect neuropeptides that mediate such diverse functions as pheromone biosynthesis, visceral muscle contraction, and induction of diapause. Although multiple forms occur in every insect studied so far, little is known about a possible functional differentiation and/or differences in the cellular expression pattern of these messenger molecules. In this study, we performed a mass spectrometric survey of all FXPRLamide-expressing neurosecretory neurons in the CNS of Periplaneta americana.

Differential sorting and packaging of capa-gene related products in an insect.

A unique costorage of neuropeptides was recently found in the abdominal perisympathetic organs (PSOs) of the American cockroach, Periplaneta americana. Having specific antisera directed against all peptides belonging to this neurosecretory system, we examined the sorting of PSO-peptides in the soma of the median neurosecretory cells of abdominal ganglia by using immunoelectron microscopic double stainings. The data indicate that all six abundant neuropeptides of this neurohormonal system, which includes three capa-gene related products, are primarily incorporated into separate vesicles.

Neuropeptides in perisympathetic organs of Manduca sexta: specific composition and changes during the development.

We used a combination of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry and immunocytochemistry to investigate the peptides from abdominal perisympathetic organs of Manduca sexta. Altogether three mass peaks, detected in mass spectra from single abdominal perisympathetic organs were identical with already known neuropeptides, namely CAP(2b), CCAP, and Manduca-allatotropin. Only CAP(2b) was found throughout the postembryonic development.

Identical cellular distribution of all abundant neuropeptides in the major abdominal neurohemal system of an insect (Periplaneta americana).

The median neurosecretory cells in abdominal ganglia of insects synthesize a number of putative hormones, which are abundant in the abdominal perisympathetic organs (PSOs). The peptide inventory of these prominent neurohemal release sites is best investigated in the American cockroach and strongly differs from that of head/thoracic neurohemal organs. In this study, we found a complete colocalization of all abundant neuropeptides in this hormonal system, including periviscerokinin-1 and -2, pyrokinin-5, YLSamide, VEAacid, and SKNacid.

The periviscerokinin (PVK) peptide family in insects: evidence for the inclusion of CAP(2b) as a PVK family member.

Periviscerokinins (PVKs) are a distinct insect peptide family with unusual distribution in the central nervous system and neurohemal release sites. PVKs were first isolated from the abdominal perisympathetic organs of Periplaneta americana, but can be found in other insect species. Peptides with structural similarity to PVKs have been identified through searches of the Drosophila genome.