The 3′,5′-adenosine-monophosphate system during the larval-adult moulting cycle in the migratory locust, Locusta migratoria

Abstract

During the larval-adult moulting cycle of the migratory locust the concentration of 3′,5′-AMP and the activities of adenylate cyclase, phosphodiesterase, protein kinase, and phosphorylase a and b were measured in wing pads and wings, and in the integument of the abdomen. In the wing pads the maximum of adenylate cyclase activity precedes the increase in 3′,5′-AMP concentration as well as the binding capacity and the 3′,5′-AMP-dependent activation of the protein kinase. Around ecdysis adenylate cyclase activity shows a minimum, but increases later. 3′,5′-AMP concentration and the nucleotide dependent protein kinase activity are decreasing in the adult locust. The protein kinase activity in absence of 3′,5′-AMP (independent protein kinase plus basal activity of dependent protein kinase) shows the highest activities in the four day old last instar and in the one day old adult. Phosphodiesterase activity stays rather constant during the instar stage but rises after ecdysis. Phosphorylase a and b increase their activities just around ecdysis. In the integument of the abdomen essentially the same pattern of concentration and activity changes can be detected, with the exception that extreme decreases during adult life do not take place.