Dynamic control of cell-cell adhesion and membrane-associated actin during food-induced mouth opening in Beroë.
We used rhodamine-phalloidin and ultrastructural methods to follow dynamic changes in adhesive cell junctions and associated actin filaments during reversible epithelial adhesion in the mouth of the ctenophore Beroë. A cruising Beroë keeps its mouth closed by interdigitated actin-coated appositions between paired strips of cells lining the lips. The mouth opens rapidly (in 0.2-0.3 s) by muscular action to engulf prey (other ctenophores), then re-seals after ingestion. We found that the interlocking surface architecture of the adhesive cells, including the actin-coated junctions, rapidly disappears after food-induced opening of the mouth. In contrast, forcible separation of the lips in the absence of food rips the junctions, still intact, from the surfaces of the cells. The prey-stimulated loss of adhesive cell junctions and associated actin cytoskeleton is one of the most rapid changes in actin-based junctions yet observed. This system provides unique experimental advantages for investigating the dynamic control of reversible cell adhesions and membrane-associated actin filaments.
Tamm
S L
SL
Boston University Marine Program, Marine Biological Laboratory, Woods Hole, MA 02543.
Tamm
S
S
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion; D003063:Cnidaria / Q000502:physiology* / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure; D004435:Eating / Q000502:physiology*; D004847:Epithelial Cells; D007365:Intercellular Junctions / Q000648:ultrastructure*; D013314:Stress, Mechanical
D000199:Actins