Cell and Tissue Research

, Volume 179, Issue 2, pp 169–175

Fine structure of the gap junction in the tunicate heart

  • V. Lorber
  • D. G. Rayns
Article

DOI: 10.1007/BF00219794

Cite this article as:
Lorber, V. & Rayns, D.G. Cell Tissue Res. (1977) 179: 169. doi:10.1007/BF00219794

Summary

The plasma membranes of the tunicate heart exhibit an abundance of macular gap junctions distributed widely over the membrane surface. A study of these junctions by the freeze-etch technique was undertaken in an effort to elucidate the fine structure of this important membrane modification in a primitive heart. In cross or near-cross fractured junctions the junctional particles in contiguous membranes appear to be paired in register and to meet in the midline. In favorable face views, the junctional particles are seen to be disposed in hexagonal array. The individual particles display a distinct rosette-like substructure consistent with a six-membered ring of globular protein molecules clustered around a central channel. Similar junctional-type particles can be found in nonjunctional areas of membrane suggesting that the transport mechanism which they may represent is not restricted to the gap junction.

Key words

Nexus Corella eumyota Traustedt Nuclear envelope Transmembrane channels Freeze-etch 

Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • V. Lorber
    • 1
    • 2
  • D. G. Rayns
    • 1
    • 2
  1. 1.Department of PhysiologyUniversity of Minnesota School of MedicineMinneapolisUSA
  2. 2.Department of AnatomyUniversity of Otago Medical SchoolDunedinNew Zealand

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