Prothoracicotropic hormone ? like activity in the embryonated eggs of gypsy moth, Lymantria dispar (L.)

Abstract

Prothoracicotropic hormone (PTTH)-like activity was obtained from embryonated eggs of the gypsy moth, Lymantria dispar. Activity was detected using an in vitro prothoracic gland stimulation bioassay. Doseresponse kinetics of crude extract revealed a 4-fold activation range with a maximum activation of 35-fold. Nearly 70% of the activity was sensitive to denaturation by heat or organic solvent extraction. Heat and organic solvent-stable activity is due to a protein. Dose-response kinetics suggest the presence of a small molecular weight PTTH with pre-hatch eggs providing a rich source of the hormone.