| Budget Amount *help |
¥11,000,000 (Direct Cost: ¥11,000,000)
Fiscal Year 2006: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2004: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Research Abstract |
In this study, we have examined in recycling system of larval cuticle protein about three systems of 1) biosynthesis, 2) degradation and 3) recycling, and aimed at the determination of molecular mechanism of a metamorphosis. Protein components analyses in the hemolymph, integument, midgut luminal contents and molting fluid in the three stages of larva, larva-pupa and pupa in Samia cynthia ricini. It became clear that BBP was synthesized in epidermis and secreted to the hemolymph and cuticle by the analyses of its antibody and gene expression. In particular, two kinds of BBP (BBP-I, BBP-II) existed in the larval hemolymph, and BBP-II existed in cuticle alone. The existence of BBP between two different body colors of larvae (blue / yellow) was compared. In yellow, new type of BBP (BBP-0) existed in the hemolymph and BBP-II like protein was found in the cuticle. These results show that BBP in the hemolymph was not accumulate into a cuticle across the epidermis and it was unrelated to larval body coloration. We examined a change of larval cuticle proteins during a metamorphosis using BBP as a marker protein. The protein degradation appeared before 72 hours of pupal ecdysis, and the degradation products were stored in the molting fluid. Finally, BBP transferred into the midgut lumen with pupation, and it was digested in the midgut with adult development. It became clear that all larval cuticle proteins were utilized in the adult development. Furthermore, we decided all amino acid sequences of BBP-I and BBP-II. In addition, hemolin like protein (48kDa) exists in a larval cuticle with high concentration. In the larval stage, this protein was related to living body defense of the cuticle. After pupation, it was to transfer into the midgut, and it related in stabilization of environment in the pupal midgut. In the latter half of pupal stage, it was utilized the materials for the formation of tissues with adult development.
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