Hormonal Interference with Pheromone Systems in Parasitic Acarines, Especially Ixodid Ticks.
Abstract
The biosynthesis and metabolism of ecdysone was investigated in the tick's 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA155854
Entities
People
- D. E. Sonenshine
- J. H. Oliver
- P. J. Homsher
Organizations
- Old Dominion University