Absence of uvomorulin in a slowly compacting variant of H6 embryonal carcinoma cells

When allowed to aggregate in calcium-containing medium, the H6 embryonal carcinoma cell variant named 6B(NG)C25 compacted more slowly than wild-type cells, and aggregates of hybrids between it and wild-type cells also compacted slowly, as if the variation (mutation) acted in a dominant fashion. In agreement with this, we now have found that the cell adhesion molecule uvomorulin is markedly reduced or absent in 6B(NG)C25 cells, as well as in the hybrids. A small amount of a higher-molecular-weight protein reacting with the antibody is present, which might represent residual uvomorulin migrating at a slower rate, an altered uvomorulin, the known precursor to uvomorulin, or an unrelated cross-reacting protein.