Sequencing of the genus Arabidopsis identifies a complex history of nonbifurcating speciation and abundant trans-specific polymorphism
Year: 2016
Type: article
Abstract: Magnus Nordborg and colleagues report a genomic analysis of all 27 known species in the genus Arabidopsis. They find evidence for a complex speciation history that is not accurately reflected by a traditional bifurcating species tree and identify widespread shared polymorphisms between species. The notion of species as reproductively isolated units related through a bifurcating tree implies that gene trees should generally agree with the species tree and that sister taxa should not share polymorphisms unless they diverged recently and should be equally closely related to outgroups. It is now possible to evaluate this model systematically. We sequenced multiple individuals from 27 described taxa representing the entire Arabidopsis genus. Cluster analysis identified seven groups, corresponding to described species that capture the structure of the genus. However, at the level of gene trees, only the separation of Arabidopsis thaliana from the remaining species was universally supported, and, overall, the amount of shared polymorphism demonstrated that reproductive isolation was considerably more recent than the estimated divergence times. We uncovered multiple cases of past gene flow that contradict a bifurcating species tree. Finally, we showed that the pattern of divergence differs between gene ontologies, suggesting a role for selection.
Source: Nature Genetics
DOI: 10.1038/ng.3617
Authors: Polina Yu Novikova, Nora Hohmann, Viktoria Nizhynska, Takashi Tsuchimatsu, Jamshaid Ali, Graham Muir, Alessia Guggisberg, Tim Paape, Karl Schmid, Olga M Fedorenko, Svante Holm, Torbjörn Säll, Christian Schlötterer, Karol Marhold, Alex Widmer, Jun Sese, Kentaro K Shimizu, Detlef Weigel, Ute Krämer, Marcus A Koch, Magnus Nordborg
Institutions: Austrian Academy of Sciences, University of Veterinary Medicine Vienna, Vienna Biocenter, Heidelberg University, Ruhr University Bochum, ETH Zurich, Institute of Integrative Biology, University of Zurich, University of Hohenheim, Russian Academy of Sciences, Institute of Biology of Karelian Research Centre, Karelian Research Centre, Mid Sweden University, Lund University, Slovak Academy of Sciences, Charles University, Institute of Botany of the Slovak Academy of Sciences, Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology, Max Planck Institute for Developmental Biology
Language: English
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
OpenAlex ID: W2498192911