Early development of gap junctions between the mouse embryonic myocardial cells. A freeze-etching study.

Using the freeze-etch technique, nexuses have been shown to exist at a very early stage in developing mouse hearts (10 dpc). At this time they are rare, but become more progressively frequent and extensive at 12 and 14 dpc. Special arrangements of particles progressively observed on the fracture faces PF (linear arrays, small associated groups of linear arrays, then hexagonal arrays with 'arms' formed by linear clusters) suggest that in ontogenesis the gap junctions may be built up by successive aggregation of the linear arrays of particles.