title: Megabase-scale inversion polymorphism in the wild ancestor of maize.
abstract: Chromosomal inversions are thought to play a special role in local adaptation, through dramatic suppression of recombination, which favors the maintenance of locally adapted alleles. However, relatively few inversions have been characterized in population genomic data. On the basis of single-nucleotide polymorphism (SNP) genotyping across a large panel of Zea mays, we have identified an ∼50-Mb region on the short arm of chromosome 1 where patterns of polymorphism are highly consistent with a polymorphic paracentric inversion that captures >700 genes. Comparison to other taxa in Zea and Tripsacum suggests that the derived, inverted state is present only in the wild Z. mays subspecies parviglumis and mexicana and is completely absent in domesticated maize. Patterns of polymorphism suggest that the inversion is ancient and geographically widespread in parviglumis. Cytological screens find little evidence for inversion loops, suggesting that inversion heterozygotes may suffer few crossover-induced fitness consequences. The inversion polymorphism shows evidence of adaptive evolution, including a strong altitudinal cline, a statistical association with environmental variables and phenotypic traits, and a skewed haplotype frequency spectrum for inverted alleles.
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN 55108, USA.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Fang
authors.forename: Tanja
authors.initials: T
authors.lastname: Pyhäjärvi
authors.forename: Allison L
authors.initials: AL
authors.lastname: Weber
authors.forename: R Kelly
authors.initials: RK
authors.lastname: Dawe
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Glaubitz
authors.forename: José de Jesus Sánchez
authors.initials: Jde J
authors.lastname: González
authors.forename: Claudia
authors.initials: C
authors.lastname: Ross-Ibarra
authors.forename: John
authors.initials: J
authors.lastname: Doebley
authors.forename: Peter L
authors.initials: PL
authors.lastname: Morrell
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ross-Ibarra
mesh_terms: D000483:Alleles; D007446:Chromosome Inversion / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics*; D019143:Evolution, Molecular; D006239:Haplotypes / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D013997:Time Factors; D003313:Zea mays / Q000235:genetics*