Isolation, characterization and FISH assignments of horse BAC clones containing type I and II markers

In order to increase the number of markers on the horse cytogenetic map and expand the integration with the linkage map, an equine BAC library was scr eened for genes and for microsatellites. Eighty-nine intra-exon primers. we re designed from consensus gene sequences in documented species. After PCR screening, 38 clones containing identified genes were isolated and FISH map ped. These data allowed us to refine the available Zoo-FISH results, to def ine ten new conserved cytogenetic segments and expand two others, thus lead ing to the identification of a total of 26 conserved segments between horse and human. Interestingly, a new homeology segment was detected between ECA 6p and HSA2q. Screening BAC clones for dinucleotide repeats led to the isol ation of 33 microsatellites. Ten of the clones each contained at least a po lymorphic microsatellite and one specific gene. The success of the approach in the production of integrative anchor loci and their potential use in lo calization and analysis of traits of interest by the candidate gene and pos itional cloning approach, are discussed. Copyright (C) 2001 S. Karger AG, B asel.