Vol. 9, Issue 12, 1239-1249, December 1999

LETTER
A Comparative Gene Map of the Horse (Equus caballus)

¹ Veterinary Genetics Laboratory, University of California Davis, Davis, California 95616-8744 USA; ² Department of Animal Science, University of California Davis, Davis, California 95616 USA; ³ Laboratory of Genomic Diversity, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201 USA; ⁴ Department of Biological Sciences, East Tennessee State University, Johnson City, Tennesee 37614 USA; ⁵ Department of Population Health and Reproduction, University of California Davis, Davis, California 95616 USA

A comparative gene map of the horse genome composed of 127 loci was assembled based on the new assignment of 68 equine type I loci and on data published previously. PCR primers based on consensus gene sequences conserved across mammalian species were used to amplify markers for assigning 68 equine type I loci to 27 horse synteny groups established previously with a horse-mouse 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 refinements of the comparative mapping data available for this species. In conjunction 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 synteny groups to chromosomes, and to further refine the genetic composition established with Zoo-FISH of two horse chromosomes. The equine type I markers developed in this study provide an important resource for the future development of the horse linkage and physical genome maps.