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Expression and localization of storage protein 1 (SP1) in differentiated fat body tissues of red hairy caterpillar, Amsacta albistriga Walker
Author(s) -
Chandrasekar Raman,
Jae Seo Sook,
Krishnan M.
Publication year - 2008
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.20266
Subject(s) - biology , hemolymph , storage protein , larva , metamorphosis , western blot , microbiology and biotechnology , biochemistry , gene , botany
The accumulation and utilization of storage proteins are prominent events linked to the metamorphosis of holometabolous insects. The female‐specific storage protein 1 (SP1) is the major storage protein found in the hemolymph and fat body of female larvae of the groundnut pest, Amsacta albistriga . Here we show SP1 expression and localization in differentiated fat body tissues using biochemical and immunohistochemistry scrutiny. Comparison of A. albistriga SP1 with that of other species with respect to amino acid composition and N‐terminal sequences show that SP1 is a methonine‐rich protein and its identity was confirmed by means of immunoblot analysis. Northern blot studies revealed that the SP1 gene demonstrates stage‐ and tissue‐specific expression in the peripheral fat body cells during the mid‐larval period of fifth instar of A. albistriga . During the larval pupal transformation, SP1 are sequestered mainly by the perivisceral fat body tissues, until they serve the purpose of supplying amino acids for the production of egg yolk proteins. Further, electron microscopic studies using immunogold tracer techniques confirmed the localization of crystalline SP1 reserves, stored in the perivisceral fat body tissues. Hence, the peripheral fat body is responsible for biosynthesis of storage proteins, whereas the perivisceral fat body is a specialized storage organ. Arch. Insect Biochem. Physiol. 69:70–84, 2008. © 2008 Wiley‐Liss, Inc.