A consensus linkage map of the chicken genome

A consensus linkage map has been developed in the chicken that combines all of the genotyping data from the three available chicken mapping population s. Genotyping data were contributed by the laboratories that have been usin g the East Lansing and Compton reference populations and from the Animal Br eeding and Genetics Group of the Wageningen University using the Wageningen /Euribrid population. The resulting linkage map of the chicken genome conta ins 1889 loci. A framework map is presented that contains 480 loci ordered on 50 linkage groups. Framework loci are defined as loci whose order relati ve to one another is supported by odds greater then 3. The possible positio ns of the remaining 1409 loci are indicated relative to these framework loc i. The total map spans 3800 cM, which is considerably larger than previous estimates for the chicken genome. Furthermore, although the physical size o f the chicken-genome is threefold smaller then that of mammals, its genetic map is comparable in size to that of most mammals. The map contains 350 ma rkers within expressed sequences, 235 of which represent identified genes o r sequences that have significant sequence identity to known genes. This im proves the contribution of the chicken linkage map to comparative gene mapp ing considerably and clearly shows the conservation of large syntenic regio ns between the human and chicken genomes. The compact physical size of the chicken genome, combined with the large size of its genetic map and the obs erved degree of conserved synteny, makes the chicken a valuable model organ ism in the genomics as well as the postgenomics era. The linkage maps, the two-point lod scores, and additional information about the loci are availab le at web sites in Wageningen (http://www.zod.wau.nl/vf/research/chick chic ken.html) and East Lansing (http://poultry.mph.msu.edu/).