Metamorphic Changes in Protein Profiles and Protease Activity in the Silkworm, Bombyx Mori during Pupal - Adult Transformation

Metamorphic changes in protein profiles vis-a-vis protease activity have been studied in the fat body and haemolymph of the silkworm, Bombyx mori during pupal-adult transformation. The trends in these two biochemical constituents run counter parallel to each other and vary as a function of certain events such as the fat body remodeling, histolysis and histogenesis that characterize silkworm metamorphosis. Most of the proteins required for pupal-adult metamorphosis are either synthesized or accumulated in the fat body during the first half and they are shunted back to the needy tissues in the latter half of the pupal and adult stages. In this process, the haemolymph plays the role of transport medium for not only bringing tissue degraded proteins to the fat body, but also for taking away the newly synthesized or processed proteins to the growing tissues such as those in gonads and other organs. The trends in protease activity indicate that the silkworm fat body undergoes a dramatic remodeling process that involves an early phase of consolidation and a latter phase of disruption with regard to its biochemical composition. The findings were correlated with the reproductive role to be played by the silkworm in its adult life.