EARLY STAGES IN REAGGREGATION OF EMBRYONIC CHICK NEURAL RETINA CELLS

A study of the initial phases of the aggregation of trypsin-dissociated embryonic neural retina reveals three major stages: (1) initial, apparently non-specific adhesions of the cells into small clusters with no definable organization; (2) orientation of cells; (3) formation of composite aggregates by accretion of the smaller cell clusters. The morphological polarity of cells is retained after dissociation but appears to play no discernible role in the location of the initial cell adhesions. Two hours after the onset of aggregation the cells within the clusters have become oriented with respect to each other in accordance with their original polarities to form concentric structures with the mitochondria-containing portion of the cell directed towards the center of the cluster. These concentric cell configurations are retained following the fusion of the small clusters into the larger, composite aggregates. © 1969.