Publication Type
Journal Article
Journal Name
Insect Biochemistry
Publication Date
1-1-1986
Abstract
Ecdysone and 20-hydroxyecdysone, the insect moulting hormones, have been tentatively identified (using TLC, radioimmunoassay and bioassay) in the eggs of the Ixodid tick Rhipicephalus appendiculatus, which is the vector of East Coast Fever (Theileriosis) in cattle. In addition, the existence of hydrophobic ecdysteroid carrier protein(s) with pI = 8.3,Kd = 5 × 10-5 M and mol. wt = ca 100,000 has been demonstrated in the egg of the tick. Engorged females, when injected with [3H]ecdysone, transport the steroid into the eggs where it is found to migrate as 20-hydroxyecdysone or polar metabolites when separated by high performance liquid chromatography. Under similar conditions [14C]4-cholesterol was not incorporated into ecdysone or 20-hydroxyecdysone. The possibility of using egg proteins as antigens to inoculate potential hosts of this tick is discussed in the light of a promising result with one rabbit, the eggs produced by ticks feeding on the ears of this animal were largely nonviable. © 1986.
Keywords
carrier protein, dissociation constant, ecdysteroids, immunodiffusion, Ixodid tick, population control, Theileriosis vector
Recommended Citation
Whitehead, D., Osir, E., Obenchain, F., & Thomas, L. (1986). Evidence for the presence of ecdysteroids and preliminary characterization of their carrier proteins in the eggs of the brown ear tick Rhipicephalus appendiculatus (Neumann). Insect Biochemistry, 16 (1), 121-133. https://doi.org/10.1016/0020-1790(86)90086-7