Possible control mechanism of cell motility in the gorgonian Eunicella cavolinii

In a previous study it was demonstrated that a lectin controls cell-cell interaction in the gorgonian Eunicella cavolinii (Koch) as a negative modulator. Now we describe the procedure to purify this lectin to homogeneity; its molecular weight is 23 400. The homologous proteoglycans were identified as positive modulators of cell-cell (and/or cell substrate) interaction. The purified single proteoglycan aggregates were 1200±700 nm long and the distance between the attachment points of the proteoglycan subunits was about 45 nm. The glycosaminoglycan residues of the gorgonian proteoglycans were identified as hyaluronic acid (35.5%), heparan sulfate (47.9%) and dermatan sulfate (14.1%). Binding studies with immobilized homologous proteoglycan preparations revealed that gorgonian cells attach to this substratum presumably via its glycosaminoglycans. Quantitative determinations of these two modulators of cell-cell recognition in the three regions of individual colonies revealed concentration gradients these concentration differences reflect a lower cell motility in the polyp-bearing branches and a higher motility of the cells in the polyp-free stem and in the basis, is discussed.