A comparative gene map of the horse (Equus caballus)

A comparative gene map of the horse genome composed of 127 loci was assembl ed based on the new assignment of 68 equine type I loci and on data publish ed previously. PCR primers based on consensus gene sequences conserved acro ss mammalian species were used to amplify markers for assigning 68 equine t ype I loci to 27 horse synteny groups established previously with a horse-m ouse somatic cell hybrid panel (SCHP, UC Davis). This increased the number of coding genes mapped to the horse genome by over 2-fold and allowed refin ements of the comparative mapping data available For this species. In conju nction with 57 previous assignments of type I loci to the horse genome map, these data have allowed us to confirm the assignment of 24 equine synteny groups to their respective chromosomes, to provisionally assign nine synten y groups to chromosomes, and to further refine the genetic composition esta blished with Zoo-FISH of two horse chromosomes. The equine type I markers d eveloped in this study provide an important resource for the future develop ment of the horse linkage and physical genome maps.