BIOSYNTHESIS AND TISSUE DISTRIBUTION OF 4 MAJOR LARVAL SERUM-PROTEINS DURING DEVELOPMENT OF CERATITIS-CAPITATA (DIPTERA)

Antibodies to the foul major larval serum proteins (MLSPs) of Ceratitis capitata were used to study the biosynthesis and tissue distribution of these proteins during larval, pupal and adult development of this species. MLSP-1,2 and 3 are synthesized only during the last larval instar and are accumulated in the haemolymph. During metamorphosis, these proteins are reabsorbed by the fat body and a fraction of them is deposited in the cuticle. MLSP-4 gives a completely different biosynthetic and accumulation pattern. The synthesis of this protein takes place at three different stages during development. The first peak of synthesis occurs at the wandering stage, about one day after the MLSP-1,2 and 3 peak, the second, about one day before adult eclosion and the third one day after adult eclosion. Furthermore, the synthesis of this protein in newly emerged adults can be stimulated by 20-hydroxyecdysone. MLSP-4 is accumulated in the haemolymph where it remains during all stages of development and is not incorporated by other tissues.