Occurrence and Metabolism of Free Amino Acids during Insect Metamorphosis

Abstract

With the partition paper chromatographic method the occurrence of free amino acids in extracts from pupae of Calliphora erythrocephala Meig. (Dipt.) and Phalera bucephala L. (Lep.) were investigated. For both the species principally the same amino acids were found. The amino acid concentration in Calliphora is comparatively constant during the whole development. There are, however, slight minima at 0–20 % and 60–80 % of pupal time. These minima may he put in relation to the histogenesis of hypodermal and muscular tissue, respectively. The Phalera pupae show an increased amino acid concentration during the latent development and a decrease during the suhitan development. By the use of Thunherg's inethylene blue method it was found that during the metimorphosis of Calliphora the enzymatic amino acid oxidation has a maximum activity at the beginning and at the end of the pupil period but is at its minimum in the middle of this period in accordance with the total metabolism. The interrelationship between amino acid oxidation, protein synthesis. and proteolysis is discussed and it is suggested that a minimum protein synthesis exists at the formation of the pupation and at the end of the pupil period, a maximum protein synthesis at pupation and during the histogenesis of the imaginal muscles after the middle of the metamorphosis period, and a relative maximum of proteolysis at 30–50 % of the papal time.