title: Multidirectional chromosome painting substantiates the occurrence of extensive genomic reshuffling within Accipitriformes.
abstract: BACKGROUND
  Previous cross-species painting studies with probes from chicken (Gallus gallus) chromosomes 1-10 and a paint pool of nineteen microchromosomes have revealed that the drastic karyotypic reorganization in Accipitridae is due to extensive synteny disruptions and associations. However, the number of synteny association events and identities of microchromosomes involved in such synteny associations remain undefined, due to the lack of paint probes derived from individual chicken microchromosomes. Moreover, no genome-wide homology map between Accipitridae species and other avian species with atypical karyotype organization has been reported till now, and the karyotype evolution within Accipitriformes remains unclear.
  
  
  RESULTS
  To delineate the synteny-conserved segments in Accipitridae, a set of painting probes for the griffon vulture, Gyps fulvus (2n = 66) was generated from flow-sorted chromosomes. Together with previous generated probes from the stone curlew, Burhinus oedicnemus (2n = 42), a Charadriiformes species with atypical karyotype organization, we conducted multidirectional chromosome painting, including reciprocal chromosome painting between B. oedicnemus and G. fulvus and cross-species chromosome painting between B. oedicnemus and two accipitrid species (the Himalayan griffon, G. himalayensis 2n = 66, and the common buzzard, Buteo buteo, 2n = 68). In doing so, genome-wide homology maps between B. oedicnemus and three Accipitridae species were established. From there, a cladistic analysis using chromosomal characters and mapping of chromosomal changes on a consensus molecular phylogeny were conducted in order to search for cytogenetic signatures for different lineages within Accipitriformes.
  
  
  CONCLUSIONS
  Our study confirmed that the genomes of the diurnal birds of prey, especially the genomes of species in Accipitriformes excluding Cathartidae, have been extensively reshuffled when compared to other bird lineages. The chromosomal rearrangements involved include both fusions and fissions. Our chromosome painting data indicated that the Palearctic common buzzard (BBU) shared several common chromosomal rearrangements with some Old World vultures, and was found to be more closely related to other Accipitridae than to Neotropical buteonine raptors from the karyotypic perspective. Using both a chromosome-based cladistic analysis as well as by mapping of chromosomal differences onto a molecular-based phylogenetic tree, we revealed a number of potential cytogenetic signatures that support the clade of Pandionidae (PHA) + Accipitridae. In addition, our cladistic analysis using chromosomal characters appears to support the placement of osprey (PHA) in Accipitridae.
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, P R China. whnie@mail.kiz.ac.cn.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Nie
authors.affiliation: Cambridge Resource Centre for Comparative Genomics, Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK. allsorter@gmail.com.
authors.forename: Patricia C M
authors.initials: PC
authors.lastname: O'Brien
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK. bf2@sanger.ac.uk.
authors.forename: Beiyuan
authors.initials: B
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, P R China. wangjing513@163.com.
authors.forename: Jinghuan
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, P R China. weitingsu@126.com.
authors.forename: Weiting
authors.initials: W
authors.lastname: Su
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, 650223, P R China. hekai@mail.kiz.ac.cn.
authors.forename: Kai
authors.initials: K
authors.lastname: He
authors.affiliation: INRA, AgroParisTech, UMR1313 Génétique Animale et Biologie Intégrative, Domaine de Vilvert-Bâtiment 320, 78352, Jouy-en-Josas Cedex, France. bertrand.bedhom@jouy.inra.fr.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Bed'Hom
authors.affiliation: Muséum National d'Histoire Naturelle, Département Systématique et Evolution, UMR 7205 Origine, Structure et Evolution de la Biodiversité, 75005, Paris, France. vvolobouev@yahoo.fr.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Volobouev
authors.affiliation: Cambridge Resource Centre for Comparative Genomics, Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK. maf12@cam.ac.uk.
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: Ferguson-Smith
authors.affiliation: Institut de Recherche pour le Développement, Centre de Biologie pour la Gestion des Populations (UMR IRD-INRA-Cirad-Montpellier SupAgro), Campus International de Baillarguet, CS30016, 34988, Montferrier-sur-Lez, France. gauthier.dobigny@ird.fr.
authors.forename: Gauthier
authors.initials: G
authors.lastname: Dobigny
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK. fy1@sanger.ac.uk.
authors.forename: Fengtang
authors.initials: F
authors.lastname: Yang
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002645:Chickens / Q000235:genetics; D020223:Chromosome Painting; D002875:Chromosomes; D046093:Falconiformes / Q000145:classification / Q000235:genetics*; D016678:Genome; D059785:Karyotype; D010802:Phylogeny; D026801:Synteny