STUDIES ON CELL AGGREGATION: DEMONSTRATION OF MATERIALS WITH SELECTIVE CELL-BINDING ACTIVITY

Abstract

(1) Studies on aggregation of sponge cells dissociated by 2 different procedures indicated that: (a) reattachment of cells might be mediated by specific materials functionally associated with the cell surface; (b) such materials could be dissolved off living cells and regenerated by cells under suitable conditions; (c) functional characteristics of these products might be involved in contact selectivity and preferential attachments of cells. (2) The existence of such products was demonstrated by obtaining cell-free preparations with selective cell-binding activity from living cells. Their effectiveness was found to be calcium dependent; they contained no detectable nucleic acids. The findings are discussed with reference to the postulated role of "extracellular" materials (ECM) in developmental associations of cells.