The turkey (Meleagris gallopavo) is an important agricultural species; it is the second largest contributor to global poultry meat production. The genomic resources of the turkey provide turkey breeders with tools needed for the genetic improvement of commercial breeds of turkey for economically important traits. A linkage map of the turkey is essential not only for the mapping of quantitative trait loci, but also as a framework to enable the assignment of sequence contigs to specific chromosomes. Comparative genomics with the chicken provides insight into mechanisms of genome evolution and helps to identify rare genomic events such as genomic rearrangements and duplications/deletions.

The aim of a study performed by the Animal Breeding and Genomics Centre was to develop a SNP-based linkage map in turkey and to detect genomic rearrangements between turkey and chicken.

Eighteen full sib families, comprising 1008 (35 F1 and 973 F2) birds, were genotyped for 775 single nucleotide polymorphisms (SNPs). Of the 775 SNPs, 570 were informative and used to construct a linkage map in turkey. The final map contains 531 markers in 28 linkage groups. The total genetic distance covered by these linkage groups is 2,324 centimorgans (cM) with the largest linkage group (81 loci) measuring 326 cM. Average marker interval for all markers across the 28 linkage groups is 4.6 cM. Comparative mapping of turkey and chicken revealed two interchromosomal and 57 intrachromosomal rearrangements between these two species.

The Wageningen turkey genetic map of 531 markers reveals a genome length of 2,324 cM. The linkage map improves on previously published maps because of the more even distribution of the markers and because the map is completely based on SNP markers. This enables easier and faster genotyping assays than the microsatellite markers used in previous linkage maps. Turkey and chicken are shown to have a highly conserved genomic structure with a relatively low number of interchromosomal and intrachromosomal rearrangements.