Developmentally regulated slime mold lectins and specific cell cohesion.

Evidence has been presented that cell surface lectins and complementary receptors appear on the surface of slime molds cells of 2 species, D. discoideum and P. pallidum, as they differentiate from a noncohesive to a cohesive form. Cohesion of P. pallidum cells measured to a quantitative assay can be blocked by reagents that would be expected to interfere with complementary interaction of cell surface lectin and receptor: namely, specific sugars, specific glycoproteins, and specific univalent antibody fragments. Although none of these experiments are definitive, the weight of the evidence suggests that at least some aspect of specific cellular cohesion is mediated by the interaction of cell surface lectins and complementary receptors.