Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2001
Publication Date: N/A
Citation: Interpretive Summary: Chemical factors that affect fluid transport in the insect excretory and digestive tracts may provide new and novel tools for the control of insect pest populations. Four peptides (small proteins) that inhibit muscular activity of the adult tobacco hornworm hindgut were isolated from the nervous system of the adult hornworm. The amino acid sequence (chemical structure) of these myoinhibitory peptides, or MIPs, was determined. The four MIPs are structurally related to each other and to two similar MIPs previously described from the hornworm, and belong to a larger family of structurally related peptides, which have been identified from other insects. The peptides may be important hormones that regulate muscular activity of the insect gut. In other insects, similar peptides have been shown to reduce levels of other important hormones that regulate growth and maturation of the insect. This information will benefit scientists that study gut function and the developmental biology of insects. Ultimately, novel insecticides or growth regulators, which mimic the biological activity the MIPs may be developed, which are safer to non-target species.
Technical Abstract: Four new myoinhibitory peptides were isolated and identified from the ventral nerve cord of adult Manduca sexta. The new peptides are related to two previously identified myoinhibitory peptides, also isolated from adult M. sexta, Mas-MIP I and Mas-MIP II. The sequences of the new peptides are APEKWAAFHGSWamide (Mas-MIP III), GWNDMSSAWamide Mas-MIP IV), GWQDMSSAWamide e(Mas-MIP V), and AWSALHGAWamide (Mas-MIP VI). Mas-MIPs III-VI were found t inhibit spontaneous peristalsis of the adult M. sexta anterior hindgut (ileum) in vitro. The Mas-MIPs are related to Lom-MIP, a myoinhibitory peptide isolated from Locusta migratoria, to four novel allatostatins isolated from the brain of Gryllus bimaculatus, and to a novel prothoracicostatin from Bombyx mori.