Mechanisms of histolysis in indirect flight muscles of alate aphid (Acyrthosiphon pisum)

We studied the changes in protein synthesis in the indirect flight muscles of alata of the pea aphid, Acyrthosiphon pisum during their development and degeneration subsequent to the final ecdysis, and obtained the following results. (1) While overall protein synthesis in flight muscles was markedly decreased during its degeneration, several proteins were induced specifically at this period. (2) In starved insects, in which the flight muscles did not degenerate, the above proteins were not induced at the same period of time. Refeeding these insects induced the same set of proteins. (3) In vitro translation of the RNA from the flight muscles suggested that induction of at least some of these proteins is regulated at the transcriptional level. (4) Injection of antibiotics that inhibit RNA and protein synthesis into insects prevented the flight muscles from degeneration. Based on these results, we suggest that flight muscle breakdown in the alate aphid, subsequent to its migratory flight, consists in programmed cell death.