Manduca sexta fat body during the larval-pupal transformation: A structural and biochemical study.

Persistent Link:
http://hdl.handle.net/10150/184688
Title:
Manduca sexta fat body during the larval-pupal transformation: A structural and biochemical study.
Author:
Willott, Elizabeth.
Issue Date:
1989
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The insect fat body is an organ that plays major roles in metabolism, storage and transport of nutrients. Of particular importance to the insect are changes that occur during the larval-pupal transformation as the insect switches from ingesting and storing nutrients to utilizing stored nutrients. Because much is known about the biochemistry of Manduca sexta during this time but little was known of the structure of the fat body, the structure of the fat body of M. sexta during the final, i.e. the fifth, larval stadium was studied using light and electron microscopy. Changes in structure of the fat body agreed with known biochemical changes that occur during the final larval stadium. Some changes included: accumulation of lipid and carbohydrate stores; acquisition of protein granules and urate; and development and loss of rough endoplasmic reticulum, Golgi complex and the plasma membrane reticular system. The protein granules appear to serve as a store of amino acids for adult proteins. In order to better understand the role of the high molecular weight larval serum proteins (LSPs) found in the hemolymph and fat body, native polyacrylamide gel electrophoresis of fat body homogenates and hemolymph was used to indicate the relative prevalence of each of the high molecular weight larval serum proteins found in M. sexta during the final larval stadium. LSPs 2 and 3, found in greater amounts in females than males, appeared in the hemolymph later than LSP4 and accumulated in the fat body to a greater extent than did LSP4. LSPs were isolated from both hemolymph and fat body. Antisera were raised against LSP3 and LSP4 (arylphorin). Screening of a cDNA expression library with antiserum to LSP4 yielded cDNA clones for the two subunits of LSP4; these were sequenced to obtain the LSP4 subunit primary structures. The two sequences are very similar, with tyrosine and phenylalanine residues being distributed fairly evenly throughout the proteins. When compared with known protein sequences, LSP4 was found to be homologous to arthropod hemocyanin proteins.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Biochemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Wells, M. A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleManduca sexta fat body during the larval-pupal transformation: A structural and biochemical study.en_US
dc.creatorWillott, Elizabeth.en_US
dc.contributor.authorWillott, Elizabeth.en_US
dc.date.issued1989en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe insect fat body is an organ that plays major roles in metabolism, storage and transport of nutrients. Of particular importance to the insect are changes that occur during the larval-pupal transformation as the insect switches from ingesting and storing nutrients to utilizing stored nutrients. Because much is known about the biochemistry of Manduca sexta during this time but little was known of the structure of the fat body, the structure of the fat body of M. sexta during the final, i.e. the fifth, larval stadium was studied using light and electron microscopy. Changes in structure of the fat body agreed with known biochemical changes that occur during the final larval stadium. Some changes included: accumulation of lipid and carbohydrate stores; acquisition of protein granules and urate; and development and loss of rough endoplasmic reticulum, Golgi complex and the plasma membrane reticular system. The protein granules appear to serve as a store of amino acids for adult proteins. In order to better understand the role of the high molecular weight larval serum proteins (LSPs) found in the hemolymph and fat body, native polyacrylamide gel electrophoresis of fat body homogenates and hemolymph was used to indicate the relative prevalence of each of the high molecular weight larval serum proteins found in M. sexta during the final larval stadium. LSPs 2 and 3, found in greater amounts in females than males, appeared in the hemolymph later than LSP4 and accumulated in the fat body to a greater extent than did LSP4. LSPs were isolated from both hemolymph and fat body. Antisera were raised against LSP3 and LSP4 (arylphorin). Screening of a cDNA expression library with antiserum to LSP4 yielded cDNA clones for the two subunits of LSP4; these were sequenced to obtain the LSP4 subunit primary structures. The two sequences are very similar, with tyrosine and phenylalanine residues being distributed fairly evenly throughout the proteins. When compared with known protein sequences, LSP4 was found to be homologous to arthropod hemocyanin proteins.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineBiochemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorWells, M. A.en_US
dc.contributor.committeememberGrimes, W. J.en_US
dc.contributor.committeememberLaw, J. H.en_US
dc.contributor.committeememberNagle, R. B.en_US
dc.identifier.proquest8915994en_US
dc.identifier.oclc702371583en_US
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