SYNTHESIS OF A HEMOLYMPH HEXAMERIN BY THE FAT-BODY AND TESTIS OF RHODNIUS-PROLIXUS

A major serum protein was purified from Rhodnius prolixus adult male haemolymph (SP2, serum protein 2) and its identity with the already described Rhodnius storage protein (SPR) was established, based on its native molecular weight (445 kDa), its reactivity with Concanavalin A, its subunit molecular weight (76 kDa) and its depletion from haemolymph in starved adults. It was shown by Western blot assay that as SP2 (SPR) is depleted from haemolymph its detection in fat body extracts increases and these events are concomitant to the termination of SP2 synthesis. Additionally, SP2 synthesis was identified in adult testis, where it was shown to undergo a cycle of accumulation and depletion, similar to that observed in the haemolymph.