title: Contrasted microcolinearity and gene evolution within a homoeologous region of wheat and barley species.
abstract: We study here the evolution of genes located in the same physical locus using the recently sequenced Ha locus in seven wheat genomes in diploid, tetraploid, and hexaploid species and compared them with barley and rice orthologous regions. We investigated both the conservation of microcolinearity and the molecular evolution of genes, including coding and noncoding sequences. Microcolinearity is restricted to two groups of genes (Unknown gene-2, VAMP, BGGP, Gsp-1, and Unknown gene-8 surrounded by several copies of ATPase), almost conserved in rice and barley, but in a different relative position. Highly conserved genes between wheat and rice run along with genes harboring different copy numbers and highly variable sequences between close wheat genomes. The coding sequence evolution appeared to be submitted to heterogeneous selective pressure and intronic sequences analysis revealed that the molecular clock hypothesis is violated in most cases.
authors.affiliation: Domaine de Melgueil, INRA-UMR DIAPC, 34130 Mauguio, France. chantret@supagro.inra.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chantret
authors.forename: Jérôme
authors.initials: J
authors.lastname: Salse
authors.forename: François
authors.initials: F
authors.lastname: Sabot
authors.forename: Arnaud
authors.initials: A
authors.lastname: Bellec
authors.forename: Bastien
authors.initials: B
authors.lastname: Laubin
authors.forename: Ivan
authors.initials: I
authors.lastname: Dubois
authors.forename: Carole
authors.initials: C
authors.lastname: Dossat
authors.forename: Pierre
authors.initials: P
authors.lastname: Sourdille
authors.forename: Philippe
authors.initials: P
authors.lastname: Joudrier
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Gautier
authors.forename: Laurence
authors.initials: L
authors.lastname: Cattolico
authors.forename: Michel
authors.initials: M
authors.lastname: Beckert
authors.forename: Sébastien
authors.initials: S
authors.lastname: Aubourg
authors.forename: Jean
authors.initials: J
authors.lastname: Weissenbach
authors.forename: Michel
authors.initials: M
authors.lastname: Caboche
authors.forename: Philippe
authors.initials: P
authors.lastname: Leroy
authors.forename: Michel
authors.initials: M
authors.lastname: Bernard
authors.forename: Boulos
authors.initials: B
authors.lastname: Chalhoub
mesh_terms: D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D003062:Codon / Q000235:genetics; D017124:Conserved Sequence; D021901:DNA, Intergenic / Q000235:genetics; D019143:Evolution, Molecular; D017343:Genes, Plant / Q000235:genetics*; D001467:Hordeum / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics; D014908:Triticum / Q000235:genetics*
chemical_list: D003062:Codon; D021901:DNA, Intergenic