Ecdysone and ecdysone-analogues: their assay and action on diapausing pupae of the cynthia silkworm.

TLDR: Abnormal development is correlated with a telescoping of the early events in adult differentiation, followed by the precocious deposition of new cuticle, and Sensitivity to excessive ecdysone or to juven...

Abstract: 1. Six ecdysones of plant origin are compared with synthetic α-ecdysone in terms of their ability to provoke normal or abnormal development of diapausing pupae and isolated pupal abdomens of the cynthia silkworm (Samia cynthia).2. The activity of the seven materials ranks in the following order: cyasterone > ponasterone B > ponasterone A > ponasterone C > α-ecdysone > β-ecdysone > inokosterone.3. All seven materials provoked normal adult development when injected in critical doses ranging from 0.2 µg. (cyasterone) to 10 µg. (inokosterone).4. All materials except µ-ecdysone caused extremely abnormal development when excessive doses were administered to pupae or isolated pupal abdomens. The typical result was the formation of naked or nearly naked non-viable moths which failed to complete adult development.5. Abnormal development is correlated with a telescoping of the early events in adult differentiation, followed by the precocious deposition of new cuticle.6. Sensitivity to excessive ecdysone or to juven...