ANALYSIS OF PROTEIN GENE-PRODUCTS IN CELL S WITH ALTERED CHROMOSOME SETS FOR THE PURPOSE OF GENETIC-MAPPING

Two-dimensional electrophoresis was used for analyzing proteins in hyb rid cells that contained single human chromosomes (chromosome 5, chrom osome 21, or chromosomes 5 and 21) against the background of the mouse genome. By comparing the protein patterns of hybrid and parent cells (about 1000 protein fractions for each kind of cell), five fractions a mong proteins of hybrid cells were supposedly identified as human prot eins. The genes of two of them are probably located on chromosome 5, a nd those of other three, on chromosome 21. Moreover, analysis of prote ins in fibroblasts of patients with the cri-du-chat syndrome (5p-) rev ealed a decrease in the content of two proteins, as compared with thos e in preparations of diploid fibroblasts. This fact was regarded as ev idence that two corresponding genes are located on the short arm of ch romosome 5. Methodological problems associated with the use of protein pattern analysis in cells with altered chromosome sets for the purpos es of genetic mapping are discussed.