Speciation via introgressive hybridization in East African cichlids?

Authors

  • W. Salzburger,

    1. Department of Zoology and Limnology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
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      *Present address: Karl-Franzens-University Graz, Department of Zoology, Universitätsplatz 2, A-8010 Graz, Austria. Fax: +43 316380 9875; E-mail: christian.sturmbauer@uni-graz.at
  • S. Baric,

    1. Department of Zoology and Limnology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
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  • C. Sturmbauer

    Corresponding author
    1. Department of Zoology and Limnology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
      Christian Sturmbauer. *Present address: Karl-Franzens-University Graz, Department of Zoology, Universitätsplatz 2, A-8010 Graz, Austria. Fax: +43 316380 9875; E-mail: christian.sturmbauer@uni-graz.at
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Christian Sturmbauer. *Present address: Karl-Franzens-University Graz, Department of Zoology, Universitätsplatz 2, A-8010 Graz, Austria. Fax: +43 316380 9875; E-mail: christian.sturmbauer@uni-graz.at

Abstract

Speciation caused by introgressive hybridization occurs frequently in plants but its importance remains controversial in animal evolution. Here we report a case of introgressive hybridization between two ancient and genetically distinct species of Lake Tanganyika cichlids that led to the formation of a new species. Neolamprologus marunguensis contains mtDNA haplotypes from both parental species varying on average by 12.4% in the first section of the control region and by 5.2% in a segment of the cytochrome b gene. All individuals have almost identical DNA sequences in the flanking regions of the single-copy nuclear DNA locus TmoM27, and show a mosaic of alleles derived from both parental lineages in six microsatellite loci. Hence, our finding displays another mode of speciation in cichlid fishes. The increase of genetic and phenotypic diversity due to hybridization may contribute to the uniquely rapid pace of speciation in cichlids.

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