Yolk-protein degradation during embryogenesis of the African migratory locust

Abstract

An analysis of the individual proteins present during the period of locust embryogenesis was undertaken using quantitative Polyacrylamide gel electrophoresis. A total of 13 bands could be resolved, some of which appeared de novo during development while others decreased or disappeared. It was found that protein use and synthesis was a well-regulated process involving periods both of high activity and of relative inactivity. The periods of most conspicuous protein changes coincided with major morphological events. The gradual degradation of several of the storage proteins was interrupted at specific times of development when they showed striking increases in concentration. The period when carbohydrates were used as an energy source could be correlated with the gradual disappearance of the carbohydrate bound to the major yolk storage protein. A number of haemolymph proteins could be demonstrated in the egg extracts. The major yolk protein was found to be immunologically identical with the female sex specific blood protein. This protein fraction had properties that were very similar to a lipovitellin reported in another insect species. A drop in the total soluble protein during early development corresponded to a previously reported increase in the free amino acid pool.