Submitted to: Peptides
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2002
Publication Date: 10/20/2002
Citation: NACHMAN, R.J., COAST, G.M., TICHY, S., RUSSELL, D.H., MILLER, J.A., PREDEL, R. OCCURRENCE OF INSECT KININS IN THE FLESH FLY, STABLE FLY AND HORN FLY - MASS SPECTROMETRIC IDENTIFICATION FROM SINGLE NERVES AND DIURETIC ACTIVITY. PEPTIDES. 2002. V. 23. p. 1885-1894.
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 such pests. The basic premise of this research is that peptides (short chains of amino acids) serve as potent internal messengers in insects to regulate vital functions. Peptides themselves are unsuitable for control measures due to their instability to enzymes in the circulatory and digestive systems, and an inability to penetrate the outer surface of the insect. 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. Before this can be accomplished, the specific structures of regulatory neuropeptides for individual pest insects must be identified. In this paper, we use state-of-the-art techniques to identify neuropeptides of the insect kinin class from single nerves in the flesh fly, stable fly and horn fly; the latter two are biting flies that are important pests in the cattle industry. Insect kinins regulate water balance, which is critical for insect survival. We have further demonstrated that the housefly can serve as a model insect for the study of peptides that regulate water balance in the stable fly and horn fly, which are difficult to rear and study. The work presented here leads us one step closer to the development of practical neuropeptide-like agents that will be effective in controlling certain pests (such as biting flies) in an environmentally friendly fashion.
Technical Abstract: MALDI-TOF mass spectrometric analysis of single lateral abdominal nerves (LAN) demonstrate the presence of the insect kinin Musdo-K in the housefly Musca domestica, and identify heretofore unknown insect kinins in two other Dipteran species as Musdo-K in the stable fly Stomoxys calcitrans and horn fly Haematobia irritans. The insect kinin native to the flesh fly Neobellieria bullata is identified as Drome-K. Musdo-K and Drome-K are identical save for the conservative substitution of Ser for Thr in position 2. The sequences of the insect kinins are therefore remarkably conserved throughout Dipterans. The in vitro Malpighian tubule fluid secretion activity of Musdo-K in the stable fly is similar to that in the housefly, whereas that of Drome-K is 30-fold more potent in the flesh fly than in the fruit fly. Given the structural identities of the kinins and CRF-like diuretic hormones of these Dipteran species, the housefly can serve as a model insect for the study of diuretic peptides and their functions in the stable fly and horn fly, both livestock pests.