Distinct frequency-distributions of homopolymeric DNA tracts in different genomes - PubMed (original) (raw)

Comparative Study

Distinct frequency-distributions of homopolymeric DNA tracts in different genomes

K J Dechering et al. Nucleic Acids Res. 1998.

Abstract

The unusual base composition of the genome of the human malaria parasite Plasmodium falciparum prompted us to systematically investigate the occurrence of homopolymeric DNA tracts in the P. falciparum genome and, for comparison, in the genomes of Homo sapiens , Saccharomyces cerevisiae , Caenorhabditis elegans , Arabidopsis thaliana , Escherichia coli and Mycobacterium tuberculosis. Comparison of theobserved frequencies with the frequencies as expected for random DNA revealed that homopolymeric (dA:dT) tracts occur well above chance in the eukaryotic genome. In the majority of these genomes, (dA:dT) tract overrepresentation proved to be an exponential function of the tract length. (dG:dC) tract overrepresentation was absent or less pronounced in both prokaryotic and eukaryotic genomes. On the basis of our results, we propose that homopolymeric (dA:dT) tracts are expanded via replication slippage. This slippage-mediated expansion does not operate on tracts with lengths below a critical threshold of 7-10 bp.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Nucleic Acids Res. 1992 Jan 25;20(2):211-5 - PubMed
    1. EMBO J. 1989 May;8(5):1517-25 - PubMed
    1. Nat Genet. 1994 Feb;6(2):114-6 - PubMed
    1. J Mol Biol. 1989 Dec 5;210(3):587-99 - PubMed
    1. Nature. 1986 Aug 14-20;322(6080):652-6 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources