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Biased Gene Conversion and Its Impact on Genome Evolution

  1. Claude Bhérer1,
  2. Adam Auton2

Published Online: 16 JUN 2014

DOI: 10.1002/9780470015902.a0020834.pub2



How to Cite

Bhérer, C. and Auton, A. 2014. Biased Gene Conversion and Its Impact on Genome Evolution. eLS. .

Author Information

  1. 1

    Université de Montréal, Montréal, Québec, Canada

  2. 2

    Albert Einstein College of Medicine, Bronx, New York, USA

Publication History

  1. Published Online: 16 JUN 2014


In most eukaryotes, genetic information is exchanged between homologous chromosomes via the process of recombination. As part of this process, short deoxyribonucleic acid (DNA) tracts of less than 1 kb in length are exchanged between chromosomes in an asymmetric fashion in a process known as gene conversion. When such gene conversion events occur within the vicinity of heterozygous loci, this asymmetric exchange of DNA can result in the non-Mendelian transmission of alleles. Multiple lines of evidence suggest that this non-Mendelian transmission is biased in favour of G and C alleles at the expense of A and T alleles. This process, known as biased gene conversion, has a number of important implications for understanding the behaviour of alleles within a population and the base composition of the genome itself.

Key Concepts:

  • Biased gene conversion is the preferential transmission of certain alleles to the next generation, arising from asymmetries in the gene conversion process.

  • Biased gene conversion appears to preferentially favour GC alleles over AT alleles, resulting in the overtransmission of GC alleles in regions of high recombination.

  • Biased gene conversion can increase the frequency of an allele in a population.

  • Consistent biased gene conversion can ultimately influence the base composition of the genome, leading to increased levels of GC content.

  • Although a difficult phenomenon to measure, multiple lines of experimental and evolutionary evidence support the existence of biased gene conversion.


  • recombination;
  • biased gene conversion;
  • GC content;
  • evolution;
  • substitution rate