Vesicle interactions as a model for the retinal cell-cell recognition mediated by R-cognin

The action of R-cognin, a chick neural retina cell recognition glycoprotein, was investigated in vesicles of retina cell membranes. It was found that the aggregation of the vesicles was dependent on membrane proteins, and specifically R-cognin, as vesicle aggregation was inhibited by R-cognin antibody (Fab'). The R-cognin content of the vesicles, and their ability to aggregate, decreased with increasing embryonic age of the tissue. R-cognin mediated aggregation of the vesicles was not dependent on exogenous calcium. Thus, R-cognin was calcium-independent in its membrane linking activity.