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Title: Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous {beta}-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed alongmore » the filopodia in {sup 35}SO{sub 4}-labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed.« less
Authors:
Publication Date:
OSTI Identifier:
5671379
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph. D.)
Publisher:
Iowa City, IA (US); Univ. of Iowa
Research Org:
Iowa Univ., Iowa City, IA (United States)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; EMBRYONIC CELLS; PHYSIOLOGY; GLYCOPROTEINS; BIOSYNTHESIS; SEA URCHINS; ONTOGENESIS; AUTORADIOGRAPHY; ELECTROPHORESIS; EMBRYOS; GLYCOSYL HYDROLASES; ION EXCHANGE CHROMATOGRAPHY; MATHEMATICAL MODELS; SCANNING ELECTRON MICROSCOPY; SULFATES; SULFUR 35; ANIMAL CELLS; ANIMALS; AQUATIC ORGANISMS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CHROMATOGRAPHY; DAYS LIVING RADIOISOTOPES; ECHINODERMS; ELECTRON MICROSCOPY; ENZYMES; EVEN-ODD NUCLEI; HYDROLASES; INVERTEBRATES; ISOTOPES; LIGHT NUCLEI; MICROSCOPY; NUCLEI; ORGANIC COMPOUNDS; OXYGEN COMPOUNDS; PROTEINS; RADIOISOTOPES; SEPARATION PROCESSES; SULFUR COMPOUNDS; SULFUR ISOTOPES; SYNTHESIS 550201* -- Biochemistry-- Tracer Techniques