GENETIC AND PHYSICAL ASSIGNMENTS OF EQUINE MICROSATELLITES - FIRST INTEGRATION OF ANCHORED MARKERS IN HORSE GENOME MAPPING

Twenty equine microsatellites were isolated from a genomic phage libra ry, and their genetical and physical localization was sought by linkag e mapping and fluorescent in situ hybridization (FISH). Nineteen of th e markers were found to be polymer phic with, in most cases, heterozyg osities exceeding 50%. The markers were mapped in a Swedish reference family for gene mapping, comprising eight half-sib families from Stand ardbred and Icelandic horse sires. Segregation was analyzed against a set of 35 other markers typed in the pedigree. Thirteen of the microsa tellites showed linkage to at least one other marker, with a total of 21 markers being involved in these linkages. In parallel, 18 of the mi crosatellites could be assigned to their chromosomal region by FISH. T hese assignments involved eight equine autosomes: ECA1, 2, 4, 6, 9, 10 , 15, and 16. The genetical and physical mappings revealed by this stu dy represent a significant extension of the current knowledge of the e quine genome map.