Concanavalin a and wheat germ agglutinin receptors on dictyostelium: Their visualization by scanning electron microscopy with microspheres

Abstract

Concanavalin A (Con A) and wheat germ agglutinin (WGA) microsphere markers are distributed in a dense, uniform array over the entire surface, including the microvilli, of glutaraldehyde-fixed D. discoideum cells in vegetative and aggregation stage cells. Labeling showed patches free of Con A receptors. Actin filaments may interact in some way with membrane components containing Con A binding sites and serve to move them to 1 pole of the cell. Surface structures appear to be involved in the Con A induced cell aggregation. Sequential labeling indicates that many, if not all, WGA receptors do not comigrate with labeled Con A receptors.