These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: [Unequal crossing over as the pathway of adaptive homologous recombination between the direct DNA repeats in tandem duplications of Escherichia coli].
    Author: Sukhodolets VV.
    Journal: Genetika; 2004 Aug; 40(8):1046-52. PubMed ID: 15523842.
    Abstract:
    Homologous recombination between direct DNA repeats within the extended tandem duplications in E. coli results from unequal sister-chromosome exchanges. This conclusion follows from the observations on the segregation of completely or partly homozygous diploid segregants by heterozygous duplications. The formation of diploid segregants with preserved heterozygosity for the unselected markers could also result from "symmetrical" intrachromosomal recombination. Analysis of the segregant genotypes, however, confirmed their formation via unequal crossing over. The data obtained indicated that in tandem duplications segregation of diploid recombinants of different types was preceded by the formation of triplications as the products of unequal sister-chromosome exchanges. In heterozygous duplications, unequal crossing over is manifested as a highly frequent adaptive exchange, providing the survival of the most part of the duplication-carrying cells on selective medium. It is suggested that adaptive mutagenesis can be the consequence of unequal sister crossing over.
    [Abstract] [Full Text] [Related] [New Search]