Tendon collagen fibrillogenesis is a multistep assembly process as revealed by quick-freezing and freeze-substitution |
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Authors: | F Mallein-Gérin R Garrone |
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Institution: | Laboratorie de Cytologie Moléculaire IBCP, CNRS UPR 412, Université Claude Bernard, Villeurbane, France. |
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Abstract: | The ultrastructure of chick embryo tendons has been examined after quick-freezing by liquid helium and freeze-substitution. Several stages of collagen assemblies were observed: intracellular packing of SLS-like aggregates surrounded by membrane containing areas with a clathrin coat; fine non cross-striated filaments connecting the cell membrane at 1 pole of the cells and collagen fibrils; tufts of filaments directly linked to collagen fibrils. This study reveals that some stages are more constant and abundant than supposed (the intracellular SLS-like aggregates) and that other extracellular assemblies that were hypothesized but usually badly preserved by conventional electron microscopy are clearly captured by the method. |
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Keywords: | collagen assembly tendon chick embryo quick-freezing freeze-substitution |
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