| Literature DB >> 3014502 |
Abstract
In this paper, we report a tandemly repeated DNA sequence found in human chromosomes. The DNA sequence, which is present at approximately 1000 copies per haploid genome, consists of a basic unit 849 base pairs (bp) long with a single specific restriction enzyme (Sau3AI) cutting site. The unit is further composed of five subunits, each approximately 170 bp long. When DNAs from various sources were examined by Southern hybridization using the repetitive DNA as a probe, a considerable degree of restriction fragment length polymorphism was observed. Furthermore, a substantial percentage (approximately 1.0%) of the same DNA sequence was also found extrachromosomally in the cultured human (HeLa) cells as monomers and oligomers of the basic unit in the form of covalently closed circular DNA. These results suggest that the repetitive DNA is unstable and prone to be excised from the chromosomes through homologous recombination.Entities:
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Year: 1986 PMID： 3014502 PMCID： PMC323802 DOI： 10.1073/pnas.83.13.4665
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205