Inhibitory effect of Concanavalin A on the cell-to-cell adhesion during early development of the starfish, Asterina pectinifera

The inhibitory effect of Concanavalin A (ConA) on the cell-to-cell adhesion was studied in starfish embryos. ConA reversibly blocked the formation of intercellular adhesion in embryos denuded of fertilization membrane as well as in normal embryos, without affecting cell division and thereby inhibiting the morphogenetic movement of blastulation. A large dose of ConA dissociated both denuded and normal embryos to single cells at blastula and gastrula stage. Succinyl ConA (Suc-ConA) has the same effect on cell-to-cell adhesion, though critical concentration was slightly higher than that of ConA. These effects of ConA or Suc-ConA were prevented by α-methyl--mannoside (αMM). Study of the binding of fluorescein-conjugated ConA to the cell surface showed that ConA receptors were present in the surface of fertilized egg and cells at all stages examined. These findings suggest that ConA receptors play an important role in cell-to-cell adhesion during the early morphogenesis of starfish.