Genomic basis of ecological niche divergence among cryptic sister species of non-biting midges

BMC Genomics

Research Article

Thomas Hankeln¹  Bastian Greshake²  Markus Pfenninger²  Barbara Feldmeyer³  Hanno Schmidt⁴ 

[1] Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg-University, Becherweg 30a, 55128, Mainz, Germany;Molecular Ecology Group, Biodiversity and Climate Research Centre (BiK-F) by Senckenberg Gesellschaft für Naturforschung and Goethe University, Biocampus Siesmayerstraße, 60054, Frankfurt am Main, Germany;Molecular Ecology Group, Biodiversity and Climate Research Centre (BiK-F) by Senckenberg Gesellschaft für Naturforschung and Goethe University, Biocampus Siesmayerstraße, 60054, Frankfurt am Main, Germany;Department of Evolutionary Biology, Johannes Gutenberg-University, Johannes-von-Müller-Weg 6, 55128, Mainz, Germany;Molecular Ecology Group, Biodiversity and Climate Research Centre (BiK-F) by Senckenberg Gesellschaft für Naturforschung and Goethe University, Biocampus Siesmayerstraße, 60054, Frankfurt am Main, Germany;Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg-University, Becherweg 30a, 55128, Mainz, Germany;

关键词: Adaptive sequence evolution;    Positive selection;    McDonald-Kreitman test;    Chironomus riparius;    Chironomus piger;   

DOI  :  10.1186/1471-2164-14-384

 received in 2013-03-01, accepted in 2013-05-30,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundThere is a lack of understanding the evolutionary forces driving niche segregation of closely related organisms. In addition, pinpointing the genes driving ecological divergence is a key goal in molecular ecology. Here, larval transcriptome sequences obtained by next-generation-sequencing are used to address these issues in a morphologically cryptic sister species pair of non-biting midges (Chironomus riparius and C. piger).ResultsMore than eight thousand orthologous open reading frames were screened for interspecific divergence and intraspecific polymorphisms. Despite a small mean sequence divergence of 1.53% between the sister species, 25.1% of 18,115 observed amino acid substitutions were inferred by α statistics to be driven by positive selection. Applying McDonald-Kreitman tests to 715 alignments of gene orthologues identified eleven (1.5%) genes driven by positive selection.ConclusionsThree candidate genes were identified as potentially responsible for the observed niche segregation concerning nitrite concentration, habitat temperature and water conductivity. Additionally, signs of positive selection in the hydrogen sulfide detoxification pathway were detected, providing a new plausible hypothesis for the species’ ecological differentiation. Finally, a divergently selected, nuclear encoded mitochondrial ribosomal protein may contribute to reproductive isolation due to cytonuclear coevolution.

【 授权许可】

Unknown   
© Schmidt et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.