Journal of Molecular Evolution

, Volume 54, Issue 4, pp 501-510

First online:

Evidence of Gene Conversion Events Between Paralogous Sequences Produced by Tetraploidization in Salmoninae Fish

  • Bernard  AngersAffiliated withLaboratoire de Génétique des Poissons, INRA, Jouy-en-Josas, France
  • , Karim  GharbiAffiliated withLaboratoire de Génétique des Poissons, INRA, Jouy-en-Josas, France
  • , Arnaud  Estoup

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


We investigated the occurrence of gene conversions between paralogous sequences of Salmoninae derived from ancestral tetraploidization and their effect on the evolutionary history of DNA sequences. A microsatellite with long flanking regions (750 bp) including both coding and noncoding sequences was analyzed. Microsatellite size polymorphism was used to detect the alleles of both paralogous counterparts and infer linkage arrangement between loci. DNA sequencing of seven Salmoninae species revealed that paralogous sequences were highly differentiated within species, especially for noncoding regions. Ten gene conversion events between paralogous sequences were inferred. While these events appears to have homogenized regions of otherwise highly differential paralogous sequences, they amplified the differentiation among orthologous sequences. Their effects were larger on coding than on noncoding regions. As a consequence, noncoding sequences grouped by orthologous lineages in phylogenetic trees, whereas coding regions grouped by taxa. Based upon these results, we present a model showing how gene conversion events may also result in the PCR amplification of nonorthologous sequences in different taxa, with obvious complications for phylogenetic inferences, comparative mapping, and population genetic studies.

Key words: Gene conversion — Microsatellite — Phylogeny — Recombination — Tetraploidization