title: The organization and rate of evolution of wheat genomes are correlated with recombination rates along chromosome arms.
abstract: Genes detected by wheat expressed sequence tags (ESTs) were mapped into chromosome bins delineated by breakpoints of 159 overlapping deletions. These data were used to assess the organizational and evolutionary aspects of wheat genomes. Relative gene density and recombination rate increased with the relative distance of a bin from the centromere. Single-gene loci present once in the wheat genomes were found predominantly in the proximal, low-recombination regions, while multigene loci tended to be more frequent in distal, high-recombination regions. One-quarter of all gene motifs within wheat genomes were represented by two or more duplicated loci (paralogous sets). For 40 such sets, ancestral loci and loci derived from them by duplication were identified. Loci derived by duplication were most frequently located in distal, high-recombination chromosome regions whereas ancestral loci were most frequently located proximal to them. It is suggested that recombination has played a central role in the evolution of wheat genome structure and that gradients of recombination rates along chromosome arms promote more rapid rates of genome evolution in distal, high-recombination regions than in proximal, low-recombination regions.
authors.affiliation: Department of Agronomy and Range Science, University of California, Davis, California 95616, USA.
authors.forename: Eduard D
authors.initials: ED
authors.lastname: Akhunov
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Goodyear
authors.forename: Shu
authors.initials: S
authors.lastname: Geng
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Qi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Echalier
authors.forename: Bikram S
authors.initials: BS
authors.lastname: Gill
authors.lastname: Miftahudin
authors.forename: J Perry
authors.initials: JP
authors.lastname: Gustafson
authors.forename: Gerard
authors.initials: G
authors.lastname: Lazo
authors.forename: Shiaoman
authors.initials: S
authors.lastname: Chao
authors.forename: Olin D
authors.initials: OD
authors.lastname: Anderson
authors.forename: Anna M
authors.initials: AM
authors.lastname: Linkiewicz
authors.forename: Jorge
authors.initials: J
authors.lastname: Dubcovsky
authors.forename: Mauricio
authors.initials: M
authors.lastname: La Rota
authors.forename: Mark E
authors.initials: ME
authors.lastname: Sorrells
authors.forename: Deshui
authors.initials: D
authors.lastname: Zhang
authors.forename: Henry T
authors.initials: HT
authors.lastname: Nguyen
authors.forename: Venugopal
authors.initials: V
authors.lastname: Kalavacharla
authors.forename: Khwaja
authors.initials: K
authors.lastname: Hossain
authors.forename: Shahryar F
authors.initials: SF
authors.lastname: Kianian
authors.forename: Junhua
authors.initials: J
authors.lastname: Peng
authors.forename: Nora L V
authors.initials: NL
authors.lastname: Lapitan
authors.forename: Jose L
authors.initials: JL
authors.lastname: Gonzalez-Hernandez
authors.forename: James A
authors.initials: JA
authors.lastname: Anderson
authors.forename: Dong-Woog
authors.initials: DW
authors.lastname: Choi
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Close
authors.forename: Muharrem
authors.initials: M
authors.lastname: Dilbirligi
authors.forename: Kulvinder S
authors.initials: KS
authors.lastname: Gill
authors.forename: M Kay
authors.initials: MK
authors.lastname: Walker-Simmons
authors.forename: Camille
authors.initials: C
authors.lastname: Steber
authors.forename: Patrick E
authors.initials: PE
authors.lastname: McGuire
authors.forename: Calvin O
authors.initials: CO
authors.lastname: Qualset
authors.forename: Jan
authors.initials: J
authors.lastname: Dvorak
mesh_terms: D002874:Chromosome Mapping / Q000379:methods / Q000706:statistics & numerical data; D032461:Chromosomes, Plant / Q000235:genetics*; D019143:Evolution, Molecular; D020131:Genes, Duplicate / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D018745:Genome, Plant; D005810:Multigene Family / Q000235:genetics; D012275:Oryza / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014908:Triticum / Q000235:genetics*
chemical_list: D005819:Genetic Markers