Localization of cytoplasmic-membrane-associated DNA in human chromosomes

In situ hybridization was used to localize the sites of the repeated sequences of cytoplasmic-membrane-associated DNA (cmDNA) in human chromosomes. cmDNA was mainly present in the heterochromatic regions of chromosomes 9. Although cmDNA has buoyant densities in neutral and alkaline CsCl gradients similar to those of human satellite C DNA, which also is localized in the heterochromatic region of chromosomes 9, cmDNA was not homologous to satellite C DNA as determined by DNA-complementary RNA hybridization. These results are in agreement with our previous studies, which indicated that cmDNA is a unique species of human DNA.