title: [The formation of an endoplasmic microfilament layer during fibroblast spreading].
abstract: Spread fibroblasts contain a dense microfilament sheath under the dorsal cell surface in the endoplasmic region. The formation of the sheath during spreading of mouse embryo fibroblasts was studied using electron microscopy of platinum replicas. At the first stages of spreading the actin meshwork comprising the pseudopodial cytoskeleton arises at the cell edges. The actin of unattached pseudopodia moves centripetally and forms a circular microfilament bundle at the endoplasm periphery. Simultaneously, the microfilament cortex in the endoplasm appears to disassemble. Due to a continuous supply of polymerized actin from the periphery to the circular bundle the latter becomes wider to cover gradually the endoplasm and to form the microfilament sheath. Anchoring of centripetally moving microfilaments at the sites of cellular contacts with the substratum leads to the formation of radial actin bundles.
authors.forename: T M
authors.initials: TM
authors.lastname: Svitkina
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure*; D000199:Actins / Q000378:metabolism; D000818:Animals; D002465:Cell Movement; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000648:ultrastructure*; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure*; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure*; D006651:Histocytochemistry; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011554:Pseudopodia / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D000199:Actins
vernacular_title: Formirovanie éndoplasmaticheskogo plasta mikrofilamentov pri rasplastyvaniia fibroblastov.