title: Meiotic adaptation to genome duplication in Arabidopsis arenosa.
abstract: Whole genome duplication (WGD) is a major factor in the evolution of multicellular eukaryotes, yet by doubling the number of homologs, WGD severely challenges reliable chromosome segregation, a process conserved across kingdoms. Despite this, numerous genome-duplicated (polyploid) species persist in nature, indicating early problems can be overcome. Little is known about which genes are involved--only one has been molecularly characterized. To gain new insights into the molecular basis of adaptation to polyploidy, we investigated genome-wide patterns of differentiation between natural diploids and tetraploids of Arabidopsis arenosa, an outcrossing relative of A. thaliana. We first show that diploids are not preadapted to polyploid meiosis. We then use a genome scanning approach to show that although polymorphism is extensively shared across ploidy levels, there is strong ploidy-specific differentiation in 39 regions spanning 44 genes. These are discrete, mostly single-gene peaks of sharply elevated differentiation. Among these peaks are eight meiosis genes whose encoded proteins coordinate a specific subset of early meiotic functions, suggesting these genes comprise a polygenic solution to WGD-associated chromosome segregation challenges. Our findings indicate that even conserved meiotic processes can be capable of nimble evolutionary shifts when required.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA, 02138, USA.
authors.forename: Levi
authors.initials: L
authors.lastname: Yant
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA, 02138, USA.
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Hollister
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA, 02138, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Wright
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA, 02138, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Arnold
authors.affiliation: School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: James D
authors.initials: JD
authors.lastname: Higgins
authors.affiliation: School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: F Chris H
authors.initials: FCH
authors.lastname: Franklin
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave., Cambridge, MA, 02138, USA.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bomblies
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D020090:Chromosome Segregation; D019143:Evolution, Molecular; D018745:Genome, Plant; D055106:Genome-Wide Association Study; D008540:Meiosis; D008969:Molecular Sequence Data; D011123:Polyploidy; D017422:Sequence Analysis, DNA; D013045:Species Specificity