Differences in density and distribution of surface glycoconjugates between normal and dystrophic mouse Schwann cells detected by statistical analyses of lectin-ferritin binding.

Cultures of Schwann cells and neurons from dorsal root ganglia of normal (C57bl/6J +/+) and dystrophic (C57bl/6J dy2j/dy2j) mice were labeled with wheat germ agglutinin (WGA) and Ricinus communis agglutinin (RCA-I) conjugated to ferritin. Statistical methods were used to compare the regional densities and distribution characteristics of lectin binding in these two types of Schwann cells, which differ in their capacities to ensheath and myelinate axons in vivo and in cultures. Regional variations in lectin binding densities and distributions were observed in both types of Schwann cells. WGA-ferritin was bound at lower densities in dystrophic mouse Schwann cells than in corresponding regions of normal cells. In both normal and dystrophic cells, WGA-ferritin was distributed at greater densities on the free surfaces of Schwann cells than on the substrate-associated surfaces. WGA-ferritin was clustered in all regions of both normal and dystrophic mouse cells. RCA-ferritin densities did not differ significantly between corresponding regions of normal and dystrophic mouse Schwann cells. However, in normal mouse Schwann cells, the density of RCA-ferritin was significantly greater in the thinner, peripheral processes of Schwann cells than in thicker perinuclear regions of the cells. Differences in the degree of RCA-ferritin clustering were also detected between normal and dystrophic Schwann cells. These results indicate that regional differences in the density and distributions of cell surface glycoconjugates occur in Schwann cells of normal and dystrophic mice.