Presence of a unique glycoconjugate on the surface of rat primordial germ cells during migration.

This investigation was undertaken to examine the chemical nature of components on the surface of primordial germ cells (PGCs) possibly related to their directed migration during development. To this end, lectins conjugated to horseradish peroxidase were used as specific histochemical probes to characterize the structure of PGC cell surface glycoconjugates and changes in their composition during and after their migration in the rat embryo. A lectin specific for terminal N-acetylgalactosamine (GalNAc) from Dolichos biflorus intensely stained the cell surface and a perinuclear region assumed to be Golgi zone of PGCs only during their migration. With one exception, no other site in the embryo stained with this lectin as migration proceeded. These observations suggest that the GalNAc-containing glycoconjugates on the surface of PGCs may be of functional importance in regulating the guidance and locomotion of these cells during the course of their extensive migration.