Tandemly repeated pentanucleotides in DNA sequences of eucaryotes.
AUTOR(ES)
Borstnik, B
RESUMO
Genetic sequence data banks were scanned in order to retrieve tandemly repeated pentanucleotides (pnts). It was found that among 102 (=(1024-4)/2/5) possible distinct pnts roughly each fourth is involved in tandem repeats. It is shown that tandemly repeated pnts are composed of frequently occurring di- and trinucleotides and that those pnts which occur frequently in the form of mono- or di-pnts form also tandem repeats either in the form of satellites or in the form of shorter tandem repeats. Human satellite III is taken as a specific example. It is shown that the first guanine within GG-AAT pnt exhibits the highest mutability. Sequential distribution of base changes gives evidence that the mutations do not occur at random positions but in a correlated fashion so that long stretches of original pnts remain intact. It is found that pnts related to the satellite III are present in introns and flanking regions of some structural genes, but are not preserved between orthologous genes of related species. The results corroborate the most plausible mechanism of their evolution--rapid amplification followed by successive divergence of repeat units by various mutational processes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=523737Documentos Relacionados
- Comparative study of DNA methylation in three unicellular eucaryotes.
- Extrachromosomal Circular DNA of Tandemly Repeated Genomic Sequences in Drosophila
- Structural instability of human tandemly repeated DNA sequences cloned in yeast artificial chromosome vectors.
- Tandemly repeated nonribosomal DNA sequences in the chloroplast genome of an Acetabularia mediterranea strain.
- Bacteriophage T4 genetic homologies with bacteria and eucaryotes.