Distinct frequency-distributions of homopolymeric DNA tracts in different genomes.
Nucleic Acids Res
; 26(17): 4056-62, 1998 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-9705519
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasmodium falciparum
/
Polidesoxirribonucleótidos
/
ADN
/
Genoma
/
Genoma de Protozoos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nucleic Acids Res
Año:
1998
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Reino Unido