Monday, December 11, 2006

Effect of PABN on fatty acid precursors of the sex pheromone in the moth Heliothis virescens Fabricius

Hanan S. Eltahlawy, hanan.eltahlawy@ndsu.edu1, James S. Buckner, hanan.eltahlawy@ndsu.edu2, and Stephen P. Foster, hanan.eltahlawy@ndsu.edu1. (1) North Dakota State University, Entomology, P.O. box 5346, Fargo, ND, (2) United State Department of Agriculture, Biosciences Research Laboratory, 1605 Albrecht Blvd, Fargo, ND

Effect of PBAN on Fatty Acid Precursors of the Sex Pheromone in the Moth Heliothis virescens Fabricius. Hanan S. Eltahlawy 1 , James S. Buckner 2 and , Stephen P. Foster 1, (1)North Dakota State University, Entomology, P.O. box 5346, fargo, ND 58105, (2)united State Department of Agriculture, Biosciences Research Laboratory, 1605 Albrecht Blvd, Fargo, ND 58105.

Sex pheromone compounds of many moth species consist of a hydrocarbon chain with a functional group and one to several double bonds. These compounds are derived from saturated fatty acids (stearic or palmitic) and biosynthesized de novo in the pheromone gland. The saturated fatty acids are modified to pheromones by several unique enzymatic steps in the gland including β-oxidation, desaturation, reduction (to alcohol), acetylation (to produce acetate) and oxidation (to produce aldehyde). Sex pheromone production in many moths is under the control of pheromone biosynthesis activating neuropeptide (PBAN). PBAN is produced in the brain-subesophageal gangalion complex and thought to be released into the hemolymph to stimulate pheromone biosynthesis in the pheromone gland. In this study we investigated the effect of PBAN on the production of the sex pheromone’s fatty acids precursors in the sex pheromone gland of decapitated Heliothis virescens females by in vivo abdominal injection of 2-C14 acetate along with PBAN or saline. At different incubation times (0.5h-8h), the total labeled lipids were extracted from the excised pheromone glands and the free fatty acids resulting from alkaline hydrolysis, were quantified by liquid scintillation analysis as their fatty acid methyl ester derivatives. Individual saturated and unsaturated fatty acids precursors were identified and quantified by HPLC. Results indicated that PBAN seems to increase the incorporation of labeled acetate into total lipids. .Investigation is underway to determine which individual fatty acids are affected by PBAN.

Species 1: Lepidoptera Noctuidae Heliothis virescens (tobacco budworm)