ARS | Publication request: A beta-amino acid pyrokinin analog induces irregular pupariation behavior in larvae of the flesh fly Sarcophaga bullata

Submitted to: Pestycydy/Pesticides
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 2007
Publication Date: November 15, 2007
Citation: Nachman, R.J., Zubrzak, P., Williams, H., Strey, A.A., Zdarek, J. 2007. A beta-amino acid pyrokinin analog induces irregular pupariation behavior in larvae of the flesh fly Sarcophaga bullata. Pestycydy/Pesticides. 210:3979-3989.

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. New, selective control measures may be developed by designing metabolically stable mimics of these neuropeptides that actively inhibit or over-stimulate functions regulated by them, resulting in disruption of the internal environment of the insect. We report on the development of a mimic of the pyrokinin neuropeptide class that elicits irregular patterns during the transformation of an immature stage of the flesh fly to the adult form, suggestive of neurotoxic properties. The irregular effects of this peptide mimic on the underlying muscular patterns that accompany this maturation process were studied in detailed fashion via a specialized technique that monitors changes in internal pressure. A deeper understanding of how these neuropeptides regulate critical processes in insects will aid in the design of strategies to disrupt insect maturation. The work brings us one step closer to the development of practical neuropeptide-like substances that will be effective in controlling pest insects in an environmentally friendly fashion.

Technical Abstract: The developmental process of pupariation is accelerated by members of the pyrokinin class of neuropeptides in larvae of the flesh fly Sarcophaga bullata. A pyrokinin analog (Ac-Y[beta-3-Phe]TPRLamide), in which a Phe residue is replaced with a beta-amino acid, accelerates pupariation in this fly at a potency (0.2 pmol/larva) that matches that of the native pyrokinin factor. At higher concentrations, this beta-amino acid pyrokinin analog induces irregular pupariation behavior patterns that are suggestive of neurotoxic properties. Biostable analogs based on this structure may in future provide analog leads with the potential to disrupt the important pupariation process in flies.