Oligodendroglia development in cell culture as monitored with a monoclonal antibody

A new marker for young oligodendrocytes has been identified by a monoclonal antibody (mOg-1, IgM isotype) prepared from cerebellar plasma membrane stimulated mouse lymphocytes. mOg-1 reactive cells in the mouse cerebellum first appear at day 19 of gestation. Future white matter layers of fixed sections of neonatal rat cerebellum were labeled with mOg-1. Although EM analysis has shown cell-surface binding by presumptive oligodendroglia in neonatal cerebellum, the antibody does not bind to compact myelin. In cell cultures prepared from 6-d-old mice, 1.1% of the cells bound mOg-1 after 3 d in culture, but up to 5% of the cells bound mOg-1 after 2 weeks in culture. Of these same Og-1-positive cells, 69% bound anti-galactocerebroside and 65% bound anti-myelin basic protein. After a week in culture Og-1-positive cells often produced lamellar sheets extending a millimeter over the polylysine substratum in the absence of normal myelin formation. mOg-1 recognizes a cell-surface determinant distinct from well-characterized oligodendroglial molecules (galactocerebroside, sulfatide and myelin basic protein) that is expressed early in oligodendrocyte development. The antibody has been used to follow the maturation of oligodendrocytes in cultures of both normal and jimpy mouse cerebellum.