Submitted to: Peptides
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/5/2011
Publication Date: 10/12/2011
Citation: Predel, R., Russell, W.K., Russell, D.H., Suh, C.P., Nachman, R.J. 2011. Neuropeptides of the cotton fleahopper, Pseudatomoscelis seriatus (Reuter). Peptides. 34:39-43. Interpretive Summary: Insect pests have developed resistance to several conventional pesticides, and new approaches are needed for pest management. Although neuropeptides (short chains of amino acids) serve as potent messengers in insects to regulate vital functions, the neuropeptides hold little promise as pest control agents because they can be degraded in the target pest. New, selective control agents may be developed by designing mimics of these neuropeptides that resist degradation and either inhibit or over-stimulate critical neuropeptide-regulated life functions. We report on the identification of neuropeptides of several classes from the central nervous system of the fleahopper, a major pest of cotton. In addition, we have mapped neuropeptide storage and release sites and characterized the structures of eight distinct peptide hormones in the nervous system of these insect pests. This information will aid in determining the functional roles of these different classes of neuropeptides in fleahoppers and other related insect pests, which may lead to development of practical neuropeptide-like substances that can effectively control pest insects in an environmentally friendly fashion.
Technical Abstract: The cotton fleahopper, Pseudatomoscelis seriatus (Reuter), is an economically important pest of cotton, and increasing concerns over resistance and safety issues associated with traditional insecticide applications have led to an interest in research on novel, alternative strategies to control them. This requires a more basic understanding of the neurohormonal system that regulates important physiological properties of the fleahopper; e.g. the expression of specific messenger molecules such as neuropeptides. A peptidomic study of neural tissues from the fleahopper led to the first identification of the sequences of native neuropeptides. These include the following neuropeptide classes: the corazonin, short neuropeptide F (sNPF), myosuppressin, CAPA-pyrokinin and -PVK peptides. The CAPA-pyrokinin, sNPF, and CAPA-PVK peptides represented novel sequences. A comparison of fleahopper neuropeptides with those of related heteropteran species indicates that they are quite different. Myosuppressin in the fleahopper is found not only in an N-terminal pyroglutamate form, but also in an unblocked form that has not been found in any other insect. The sNPF of P. seriatus shows, among others, a novel substitution of Leu with Phe within the C-terminal region; a modification that sets it apart from the known sNPFs of not only other Heteroptera but of other arthropod species as well. The identity of the neuropeptides native to the fleahopper can aid in the potential development of biostable, bioavailable mimetic agonists and antagonists capable of disrupting the physiological functions that these neuropeptides regulate.