Gap junctions in development--a perspective.

The status of the gap junction as a pathway for cellular interactions during development is reviewed. Current evidence suggests that gap junctions play an important part in ensuring normal development, although the precise role of gap junctional communication remains to be defined. Communication through gap junctions acts alongside cellular interactions achieved by the release of growth factors during embryogenesis. Differences between groups of developing cells may be reflected in, and possibly controlled by, alterations in the selectivity of the gap junctions. It seems likely that gap junctional communication is involved in the control of embryonic patterning rather than phenotypic differentiation.