|Lopez, Juan de dios|
|Nachman, Ronald - Ron|
Submitted to: Peptides
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/2/2009
Publication Date: 3/15/2010
Citation: Neupert, S., Russell, W.K., Russell, D.H., Lopez, J., Predel, R., Nachman, R.J. 2010. Neuropeptides in Heteroptera: Identification of allatotropin-related peptide and tachykinin-related peptides using MALDI-TOF mass spectrometry. Peptides. 30:483-488. Interpretive Summary: Because of problems with the development of resistance to conventional pesticides, there is a critical need for new concepts and alternative approaches in controlling insect pests. The basic premise of this research is that neuropeptides (short chains of amino acids) serve as potent messengers in insects to regulate vital functions. Nevertheless, neuropeptides in and of themselves hold little promise as pest control agents because of susceptibility to being degraded in the target pest. Neuropeptide mimics must be designed that resist degradation by enzymes in the digestive tract and blood of pest insects, and that interact with the active site within agricultural pests by over-activating or blocking critical, neuropeptide-regulated life functions. The first step is to identify neuropeptide structures in specific insect pests and map sites of production and storage within the nervous system. We report on the identification of neuropeptides of the allatotropin and tachykinin-related classes from the central nervous system of four species of stink bugs and several other distantly related bugs. In addition, storage and release sites have been mapped in the nervous systems of these insect pests. Specifically, we have used state-of-the-art analytical techniques to determine the structures of over seven peptides from the four species of stink bug. These peptides are associated with regulation of development, reproduction, and hibernation-like states that enhance winter survival in other insects. This work represents an important milestone and lead in the development of practical neuropeptide-like substances that will effectively control insect pests in an environmentally friendly fashion.
Technical Abstract: Recently, the peptidomic analysis of neuropeptides from the retrocerebral complex and abdominal perisympathetic organs of polyphagous stinkbugs (Pentatomidae) revealed the group-specific sequences of pyrokinins, CAPA peptides (CAPA-periviscerokinins/PVKs and CAPA-pyrokinin), myosuppressin, corazonin, adipokinetic hormone, and short neuropeptide F. In this study, we used mass spectrometric profiling of nervous tissue from the species-rich taxon Hemiptera to identify products of two previously unobserved neuropeptide genes from these species, namely allatotropin-related peptide (ATRP) and tachykinin-related peptides (TKRPs). Since neither TKRPs nor allatotropin are accumulated in neurohemal organs, immunocytochemical data were analyzed to find potential accumulation sites within the central nervous system. By mass spectrometry, TKRPs were found to be accumulated in the antennal lobes, and ATRP was identified in the most posterior region of the abdominal ventral nerve cord and fourth abdominal nerves. In addition to neuropeptides from stink bugs, TKRPs and ATRP were also identified from the distantly related bugs Oncopeltus fasciatus (Lygaeidae) and Pyrrhocoris apterus (Pyrrhocoridae). In total, six TKRPs and one ATRP from each species could be elucidated by tandem mass spectrometry. The ATRP of all species is sequence-identical with Locusta migratoria accessory gland myotropin-1 (Lom-AG-MT-1), a member of the highly conserved insect allatotropin family.