ISOLATION OF CHROMOSOME-SPECIFIC PAINTS FROM HIGH-RESOLUTION FLOW KARYOTYPES OF THE SHEEP (OVIS-ARIES)

High-resolution bivariate flow karyotypes were obtained using fibrobla st cell lines from a sheep with a normal karyotype (2n=54), from sheep carrying Robertsonian translocation chromosomes and from sheep-hamste r somatic cell hybrids. By taking advantage of the presence of chromos ome polymorphisms, translocation chromosomes and sheep-hamster somatic cell hybrids, all sheep chromosomes were isolated by flow sorting. Ch romosome-specific paints were generated from each sorted peak using de generate oligonucleotide-primed polymerase chain reaction (DOP-PCR), T he sheep chromosome present in each peak was identified by chromosome- specific microsatellite analysis of the DOP-PCR products and fluoresce nce in situ hybridization (FISH) onto DAPI-banded sheep metaphase chro mosomes, The chromosome-specific DNA obtained in this study can be use d for the production of genomic libraries and as a resource for mappin g randomly cloned DNA sequences that will greatly aid the construction of genetic and physical maps in the sheep. The chromosome-specific pa ints will facilitate chromosome identification and contribute to the s tudy of karyotype evolution in the sheep and related species.