title: Hybrid incompatibility in Arabidopsis is determined by a multiple-locus genetic network.
abstract: The cross between Arabidopsis thaliana and the closely related species Arabidopsis arenosa results in postzygotic hybrid incompatibility, manifested as seed death. Ecotypes of A. thaliana were tested for their ability to produce live seed when crossed to A. arenosa. The identified genetic variation was used to map quantitative trait loci (QTLs) encoded by the A. thaliana genome that affect the frequency of postzygotic lethality and the phenotypes of surviving seeds. Seven QTLs affecting the A. thaliana component of this hybrid incompatibility were identified by crossing a Columbia × C24 recombinant inbred line population to diploid A. arenosa pollen donors. Additional epistatic loci were identified based on their pairwise interaction with one or several of these QTLs. Epistatic interactions were detected for all seven QTLs. The two largest additive QTLs were subjected to fine-mapping, indicating the action of at least two genes in each. The topology of this network reveals a large set of minor-effect loci from the maternal genome controlling hybrid growth and viability at different developmental stages. Our study establishes a framework that will enable the identification and characterization of genes and pathways in A. thaliana responsible for hybrid lethality in the A. thaliana × A. arenosa interspecific cross.
authors.affiliation: Genome Center and Section of Plant Biology, University of California, Davis, California 95616, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Burkart-Waco
authors.forename: Caroline
authors.initials: C
authors.lastname: Josefsson
authors.forename: Brian
authors.initials: B
authors.lastname: Dilkes
authors.forename: Nora
authors.initials: N
authors.lastname: Kozloff
authors.forename: Otto
authors.initials: O
authors.lastname: Torjek
authors.forename: Rhonda
authors.initials: R
authors.lastname: Meyer
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
authors.forename: Luca
authors.initials: L
authors.lastname: Comai
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000235:genetics*; D004843:Epistasis, Genetic; D053263:Gene Regulatory Networks; D017343:Genes, Plant; D006824:Hybridization, Genetic; D040641:Quantitative Trait Loci; D012639:Seeds