title: Integrated maps in quail (Coturnix japonica) confirm the high degree of synteny conservation with chicken (Gallus gallus) despite 35 million years of divergence.
abstract: BACKGROUND
  By comparing the quail genome with that of chicken, chromosome rearrangements that have occurred in these two galliform species over 35 million years of evolution can be detected. From a more practical point of view, the definition of conserved syntenies helps to predict the position of genes in quail, based on information taken from the chicken sequence, thus enhancing the utility of this species in biological studies through a better knowledge of its genome structure. A microsatellite and an Amplified Fragment Length Polymorphism (AFLP) genetic map were previously published for quail, as well as comparative cytogenetic data with chicken for macrochromosomes. Quail genomics will benefit from the extension and the integration of these maps.
  
  
  RESULTS
  The integrated linkage map presented here is based on segregation analysis of both anonymous markers and functional gene loci in 1,050 quail from three independent F2 populations. Ninety-two loci are resolved into 14 autosomal linkage groups and a Z chromosome-specific linkage group, aligned with the quail AFLP map. The size of linkage groups ranges from 7.8 cM to 274.8 cM. The total map distance covers 904.3 cM with an average spacing of 9.7 cM between loci. The coverage is not complete, as macrochromosome CJA08, the gonosome CJAW and 23 microchromosomes have no marker assigned yet. Significant sequence identities of quail markers with chicken enabled the alignment of the quail linkage groups on the chicken genome sequence assembly. This, together with interspecific Fluorescence In Situ Hybridization (FISH), revealed very high similarities in marker order between the two species for the eight macrochromosomes and the 14 microchromosomes studied.
  
  
  CONCLUSIONS
  Integrating the two microsatellite and the AFLP quail genetic maps greatly enhances the quality of the resulting information and will thus facilitate the identification of Quantitative Trait Loci (QTL). The alignment with the chicken chromosomes confirms the high conservation of gene order that was expected between the two species for macrochromosomes. By extending the comparative study to the microchromosomes, we suggest that a wealth of information can be mined in chicken, to be used for genome analyses in quail.
authors: Laboratoire de Génétique Cellulaire, Centre INRA de Toulouse, BP 52627 Auzeville, 31326 Castanet Tolosan, France. bbkayang@ug.edu.gh
authors: Boniface B
authors: BB
authors: Kayang
authors: Valérie
authors: V
authors: Fillon
authors: Miho
authors: M
authors: Inoue-Murayama
authors: Mitsuru
authors: M
authors: Miwa
authors: Sophie
authors: S
authors: Leroux
authors: Katia
authors: K
authors: Fève
authors: Jean-Louis
authors: JL
authors: Monvoisin
authors: Frédérique
authors: F
authors: Pitel
authors: Matthieu
authors: M
authors: Vignoles
authors: Céline
authors: C
authors: Mouilhayrat
authors: Catherine
authors: C
authors: Beaumont
authors: Shin'ichi
authors: S
authors: Ito
authors: Francis
authors: F
authors: Minvielle
authors: Alain
authors: A
authors: Vignal