Reassociation kinetics of polyploid hepatocyte DNA

The state of ploidy of 4c hepatocytes is examined by kinetic analysis of DNA reassociation. The nucleotide sequences present in 4c hepatocyte DNA are found to be complementary to, and present in the same relative abundance as, those of the normal diploid genome. Therefore, these experiments indicate that the increased DNA content of 4c hepatocytes is due to the presence of four haploid genomes and not to selective replication of a subfraction of the diploid genome. The concept of ploidy, typically defined in terms of karyotypic and/or DNA content multiples is thus corroborated and extended by these experiments.