Secretion and Uptake of 14C Proteins by Fat Body of Calpodes ethlius Stoll. (Lepidoptera, Hesperiidae)

Abstract

Insect fat body from larvae of Calpodes ethlius synthesised proteins in vitro , some of which were secreted into the medium. 14 C leucine was incorporated into fat-body proteins and the released proteins were characterised by electrophoresis and immunodiffusion. The released proteins included the three main proteins normally found in larval hemolymph and fat body. Larval fat body in the main synthetic phase of development did not sequester these 14 C-labelled proteins when incubated with them in vitro or when they were injected into mid-instar larvae. In contrast, these proteins were sequestered by fat-body cells undergoing pupation. The conclusion is that larval fat-body cells in the main synthetic phase selectively exclude proteins synthesised in vitro by fat body of the same age. During pupal development the fat body absorbs proteins it secreted at an earlier age.