Toward a dog radiation hybrid map

Dog fibroblasts grown from a biopsy performed in a male mongrel were fused after gamma irradiation with thymidine kinase-deficient hamster cells and c ultivated in selection medium, A total of 148 clones were obtained and scre ened by means of PCR amplification using primers corresponding to a dog-spe cific short repetitive element and to dog microsatellites and genes. One hu ndred seven cell lines were selected and grown in roller bottles and the di stribution of 39 markers was analyzed in the extracted DNA, The results cle arly indicate that this panel of hybrid cell lines should prove invaluable for constructing a map of the canine genome, In parallel, for more than 500 microsatellites present in the databases or screened from two libraries of short inserts, we have determined PCR conditions favoring dog-specific pro ducts even in the presence of hamster DNA, These highly polymorphic microsa tellites should be useful in further linkage studies. We have also characte rized 254 markers: dog genes, human expressed sequenced tags (huESTs), and traced orthologous amplified sequenced tags (TOASTs), Once mapped, these wi ll constitute powerful tools to detect regions of conserved synteny in huma n and other mammalian genomes.