title: The physical map of wheat chromosome 1BS provides insights into its gene space organization and evolution.
abstract: BACKGROUND
  The wheat genome sequence is an essential tool for advanced genomic research and improvements. The generation of a high-quality wheat genome sequence is challenging due to its complex 17 Gb polyploid genome. To overcome these difficulties, sequencing through the construction of BAC-based physical maps of individual chromosomes is employed by the wheat genomics community. Here, we present the construction of the first comprehensive physical map of chromosome 1BS, and illustrate its unique gene space organization and evolution.
  
  
  RESULTS
  Fingerprinted BAC clones were assembled into 57 long scaffolds, anchored and ordered with 2,438 markers, covering 83% of chromosome 1BS. The BAC-based chromosome 1BS physical map and gene order of the orthologous regions of model grass species were consistent, providing strong support for the reliability of the chromosome 1BS assembly. The gene space for chromosome 1BS spans the entire length of the chromosome arm, with 76% of the genes organized in small gene islands, accompanied by a two-fold increase in gene density from the centromere to the telomere.
  
  
  CONCLUSIONS
  This study provides new evidence on common and chromosome-specific features in the organization and evolution of the wheat genome, including a non-uniform distribution of gene density along the centromere-telomere axis, abundance of non-syntenic genes, the degree of colinearity with other grass genomes and a non-uniform size expansion along the centromere-telomere axis compared with other model cereal genomes. The high-quality physical map constructed in this study provides a solid basis for the assembly of a reference sequence of chromosome 1BS and for breeding applications.
authors.forename: Dina
authors.initials: D
authors.lastname: Raats
authors.forename: Zeev
authors.initials: Z
authors.lastname: Frenkel
authors.forename: Tamar
authors.initials: T
authors.lastname: Krugman
authors.forename: Itay
authors.initials: I
authors.lastname: Dodek
authors.forename: Hanan
authors.initials: H
authors.lastname: Sela
authors.forename: Hana
authors.initials: H
authors.lastname: Simková
authors.forename: Federica
authors.initials: F
authors.lastname: Magni
authors.forename: Federica
authors.initials: F
authors.lastname: Cattonaro
authors.forename: Sonia
authors.initials: S
authors.lastname: Vautrin
authors.forename: Hélène
authors.initials: H
authors.lastname: Bergès
authors.forename: Thomas
authors.initials: T
authors.lastname: Wicker
authors.forename: Beat
authors.initials: B
authors.lastname: Keller
authors.forename: Philippe
authors.initials: P
authors.lastname: Leroy
authors.forename: Romain
authors.initials: R
authors.lastname: Philippe
authors.forename: Etienne
authors.initials: E
authors.lastname: Paux
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Doležel
authors.forename: Catherine
authors.initials: C
authors.lastname: Feuillet
authors.forename: Abraham
authors.initials: A
authors.lastname: Korol
authors.forename: Tzion
authors.initials: T
authors.lastname: Fahima
mesh_terms: D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D023061:Gene Order; D017343:Genes, Plant; D023281:Genomics / Q000379:methods; D020161:Physical Chromosome Mapping / Q000379:methods*; D014908:Triticum / Q000235:genetics*