The synthesis and uptake of haemolymph storage proteins by the fat body of the greater wax moth Galleria mellonella (L.)

Abstract

The four storage proteins of Galleria mellonella (L.) exhibit stage-dependent alterations in distribution between haemolymph and fat body during the final larval instar. Autoradiograms of newly synthesized fat body proteins separated on sodium dodecyl sulphate polyacrylamide gels demonstrated that this tissue both synthesizes and releases all four storage proteins until pharate pupal development. Although the capacity for protein biosynthesis by fat bodies fluctuated during this period of development, qualitative alterations in the synthesis of the storage proteins were not found. Fat body from wandering through to spinning stage larvae sequestered radiolabelled storage proteins which had been injected into the haemolymph. This provides evidence for the direct resorption of haemolymph storage proteins by fat body; however, it may only in part account for the storage protein pool accumulated by pharate pupal and pupal fat body tissues.