Hormonal Interference with Pheromone Systems in Parasitic Acarines, Especially Ixodid Ticks.
Annual technical rept. no. 5, 1 May 84-30 Apr 85,
OLD DOMINION UNIV NORFOLK VA DEPT OF BIOLOGICAL SCIENCES
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The biosynthesis and metabolism of ecdysone was investigated in the ticks Dermacentor variabilis and Hyalomma dromedarii. Following synthesis from cholesterol, ecdysone is metabolized to 20-hydroxyecdysone and, subsequently, a spectrum of predominantly apolar ecdysteroids. Despite the large variety of ecdysteroids present in these ticks, only one active hormone, 20-OH ecdysone, occurs. Most of the ecdysone and 20-OH ecdysone is conjugatged with unknown compounds, resulting in much more apolar compounds. Saponification or treatment with esterases resulted in breakdown of the apolar compounds, releasing 20-OH ecdysone and other more polar unknown compounds. The results implicate esterification of the tick ecdysteroids with fatty acids. However, no evidence of fatty acids was found in the hydrolysates following saponification or enzymatic hydrolysis. The matabolism of exogenous juvenile hormone JH was also investigated by incubating authenitc 3H JH with tick hemolymph. The potential use of ecdysteroid analogues to disrupt development and sexpheromone activity was investigated. New evidence of a JH-like gonadotropic hormone was found in mites and ticks. Originator supplied keywords Hormones ecdysteroids metabolism gel electrophoresis pheromones radioimmunoassay juvenile hormones High Performance Liquid Chromatography apolysis parabiosis transplantation techniques autoradiography Hylomma dromedarii Dermacentro variabilis Ornithodoros parkeri.
- *SEX HORMONES
- CHEMICAL REACTIONS
- LIQUID CHROMATOGRAPHY
- FATTY ACIDS
- SAPONIFICATION NUMBER