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Identifying DNA Mutations in Purified Hematopoietic Stem/Progenitor Cells
11:06

Identifying DNA Mutations in Purified Hematopoietic Stem/Progenitor Cells

Published on: February 24, 2014

Amplification of mutator cells in a population as a result of horizontal transfer

P Funchain1, A Yeung, J Stewart

  • 1Department of Microbiology and Molecular Genetics, University of California, Los Angeles, California 90095, USA.

Journal of Bacteriology
|May 24, 2001
PubMed

Insights

Mutator cells lacking mismatch repair (MMR(-)) dramatically increase after interspecies mating and selection. This suggests horizontal gene transfer can drive the evolution of mutator strains during adaptation.

Area of Science:

  • Microbiology
  • Evolutionary Biology
  • Genetics

Background:

  • Mutator cells, deficient in the mismatch repair system (MMR(-)), are rare in wild-type populations.
  • Understanding the evolutionary dynamics of mutator cells is crucial for comprehending adaptation and genome stability.

Purpose of the Study:

  • To investigate the frequency and evolution of mismatch repair deficient (MMR(-)) cells under specific selective conditions.
  • To explore the role of horizontal gene transfer in the proliferation of mutator strains.

Main Methods:

  • Interspecies bacterial mating (Salmonella enterica serovar Typhimurium and Escherichia coli) followed by selection for recombinants.
  • Serial mating and selection experiments.
  • Coupling of bacterial crosses with mutagenesis or selection for spontaneous mutants.

Main Results:

  • The percentage of MMR(-) cells increased significantly (to several percent) after a single interspecies mating and selection.
  • Following a second successive mating and selection, MMR(-) cells constituted over 95% of the recombinant population.
  • Combining bacterial crosses with mutagenesis or mutant selection also led to a substantial rise in MMR(-) cells.

Conclusions:

  • Interspecies horizontal gene transfer, coupled with selection, strongly favors the proliferation of mismatch repair deficient (MMR(-)) cells.
  • These findings indicate that horizontal gene transfer can be a significant mechanism driving the emergence and dominance of mutator strains during adaptive evolution.

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