Cell surface events during resealing visualized by scanning-electron microscopy

Paul L McNeil, Marilyn M. Baker

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The function of exocytosis during plasma membrane resealing might be to facilitate the flow of surface lipid over the disruption site and/or to add defect-spanning "patches" of internal membrane across it. Scanning-electron-microscopic visualization of large plasma membrane disruptions in sea urchin eggs is here used to distinguish between these two possibilities. Disruptions were induced by shear stress in the presence and absence of resealing-permissive levels of external Ca2+, and the eggs were fixed at various intervals thereafter for microscopic processing. In eggs fixed immediately (<1 s) after shearing in the absence of Ca2+, a condition which prevents resealing, disruption sites were filled with a uniform population of spherical vesicles (∼1 μm in diameter). In eggs fixed immediately after shearing at a resealing-permissive level of Ca2+, disruption sites were filled with a highly heterogeneous population of enlarged vesicles, some being more than 10 μm in diameter and many having irregular profiles and/or appearing to be joined to one another. In eggs fixed 2 s or 5 s post-shearing, the continuity of these large vesicles with one another and the surface membrane began to obscure individual vesicle identities. Single "apertures" of discontinuity over disruption sites, the predicted morphology of a flow-based resealing mechanism, were not observed at any time point (1-5 s) during the interval required for completion of resealing. These observations provide strong confirmation that "patching" of large disruptions mediates their resealing.

Original languageEnglish (US)
Pages (from-to)141-146
Number of pages6
JournalCell and Tissue Research
Volume304
Issue number1
DOIs
StatePublished - May 12 2001

Fingerprint

Shearing
Electron Scanning Microscopy
Eggs
Cell membranes
Scanning electron microscopy
Membranes
Cell Membrane
Shear stress
Visualization
Sea Urchins
Scanning
Exocytosis
Lipids
Defects
Electrons
Population
Processing

Keywords

  • Disruption
  • Fusion
  • Lytechinus pictus
  • Patch
  • Plasma membrane
  • Resealing
  • Sea urchin
  • Stronglyocentratus purpuratus
  • Vesicle

ASJC Scopus subject areas

  • Anatomy
  • Clinical Biochemistry
  • Cell Biology

Cite this

Cell surface events during resealing visualized by scanning-electron microscopy. / McNeil, Paul L; Baker, Marilyn M.

In: Cell and Tissue Research, Vol. 304, No. 1, 12.05.2001, p. 141-146.

Research output: Contribution to journalArticle

McNeil, Paul L ; Baker, Marilyn M. / Cell surface events during resealing visualized by scanning-electron microscopy. In: Cell and Tissue Research. 2001 ; Vol. 304, No. 1. pp. 141-146.
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