THE EXTRACELLULAR MATRIX OF VOLVOX CARTERI.
Item
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Title
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THE EXTRACELLULAR MATRIX OF VOLVOX CARTERI.
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Identifier
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AAI8801768
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identifier
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8801768
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Creator
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TEMPLEMAN, MALKA NAOMI.
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Contributor
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Roy E. McGowan
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Date
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1987
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, General
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Abstract
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The extracellular matrix of Volvox carteri f. nagariensis has been isolated and its composition correlated with morphological changes of the normal developmental cycle. Radioactive and non-radioactive matrix components of two strains of Volvox (HK10 and NB7) were extracted and fractionated by column chromatography. The matrix was found to consist of two major fractions, a complex polysaccharide and a lower molecular weight glycoprotein.;Matrix extracted from Volvox at specific stages of the life cycle exhibited altered ratios of carbohydrate to protein as a function of development. The carbohydrate/protein ratio increases from {dollar}\sim{dollar}1:1 to {dollar}\sim{dollar}3:1 as the newly released spheroid grows to the fully expanded pre-release stage. Pulse labeling of the matrix during specific developmental intervals revealed that the increase in the polysaccharide fraction was due to de novo synthesis during pre-release expansion. Matrix extracted from strain NB7 was very similar in biochemical composition and elution profile to the matrix of strain HK10.;DIS 111, a mutant of strain HK10 defective in the synthesis and deposition of extracellular matrix, was compared cytologically to the normal spheroid by means of electron microscopy. Electron dense regions surrounding both the individual cells of the normal spheroid and lining the outer surface of the spheroid were absent from DIS 111. Extracellular material synthesized by DIS 111 was recovered from the medium, concentrated, and separated by exclusion gel chromatography. This analysis revealed diminished polysaccharide and protein "matrix like" components.;Extracellular material was extracted from the related genus Chlamydomonas during the stress induced "palmelloid" phase wherein individual cells are embedded in a matrix like material. Palmelloid extracellular material was fractionated and found to compare closely to normal Volvox matrix.;The glycoprotein fraction of the matrix, extracted from heterogeneous spheroids of HK10 and NB7, was compared on 10% SDS-polyacrylamide gel slabs and on 5%-15% gradient gels. Approximately seven proteins were homologous to both strains and each strain contained its own specific polypeptide. Matrix glycoproteins from HK10 spheroids at specific developmental stages of the life cycle were electrophoresed on gradient gels. Certain polypeptide bands were found to be stage specific, whereas others were common throughout the life cycle.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biology
