Relation between the rate of cell movement under agarose and the positioning of cells in heterotypic aggregates

Single-cell suspensions prepared from 9-day-old chick tissues (skeletal muscle, liver, and neural retina) were used to investigate a possible relationship between intrinsic mobilities of different cell types and their positioning behavior in mixed (heterotypic) cellular aggregates. The relative mobilities of the three cell types, determined by comparing their ability to migrate under an agarose layer, was muscle greater than liver greater than neural retina. The gyratory shaker method was employed to produce heterotypic aggregates from mixed suspensions of muscle, liver, and neural retina cells and the tissue-specific positioning of cells after 24 h in culture was determined from histological and autoradiograph sections. The hierarchy for "inside" positioning of segregated cells was muscle greater than liver greater than neural retina cells, correlating with the rate of movement of these cells in the migration assay. The implication of the results is that relative speed of movement may determine the positioning of cells in heterotypic aggregates.