The effect of inhibition of RNA and protein synthesis on the development of larvae of Locusta migratoria

Abstract

Actinomycin D and cycloheximide were used to inhibit RNA and protein synthesis in 4th and 5th instar larvae of Locusta migratoria. A maximum of 60% inhibition of RNA synthesis was obtained. The effect quickly declined and by ten hours after injection, RNA synthesis was higher in treated animals than in controls. Injection of actinomycin D into early 4th instar larvae caused the development of 5th instar larvae with greenish cuticle and modified pronota. Cycloheximide caused almost complete inhibition of protein synthesis. The effect declined gradually over a period of 24 hr. Injection of cycloheximide into 4th instar larvae caused the development of 5th instar larvae which resemble solitaria larvae in many respects. The mechanisms whereby these effects are brought about are discussed.