Loss of expression of the uvomorulin gene in compaction-defective embryonal carcinoma cells.

The lack of uvomorulin protein in the 6B(NG)C25 subline of H6 embryonal carcinoma cells is due to loss of expression of the uvomorulin gene, without evidence of gross alteration in the gene itself. This suggests that the dominant mutation in 6B(NG)C25 may involve a trans-acting factor involved in the regulation of uvomorulin gene expression.