Protein synthesis in the fat body of the female desert locust, Schistocerca gregaria Forsk., in relation to maturation

Abstract

A method is described for studying the ability of the locust fat body to synthesize protein in vitro. In adult females protein synthesis was low soon after the molt, but rapidly increased to a peak 1 or 2 days later. It then dropped and leveled off until the eggs began to develop, when there was a further rapid increase. Three substances that have been shown to stimulate maturation were injected into newly molted females and the rate of protein synthesis by their fat bodies in vitro measured some hours later. Extracts of the corpus cardiacum increased the rate of protein synthesis by the fat body, and very high activity was recorded for both protein and RNA synthesis 4 hours after injection. Ethylene chlorhydrin and gibberellin A 3 did not significantly alter the rate of protein synthesis and it was concluded that these substances must stimulate maturation indirectly, probably through the endocrine system.