A MAP OF 75 HUMAN RIBOSOMAL-PROTEIN GENES

We mapped 75 genes that collectively encode >90% of the proteins Found in human ribosomes. Because localization of ribosomal protein genes ( rp genes) is complicated by the existence of processed pseudogenes, mu ltiple strategies were devised to identify PCR-detectable sequence-tag ged sites (STSs) at introns. In some cases we exploited specific, pre- existing information about the intron/exon structure of a given human rp gene or its homolog in another vertebrate. When such information wa s unavailable, selection of PCR primer pairs was guided by general ins ights gleaned h-om analysis of all mammalian rp genes whose intron/exo n structures have been published, for many genes, PCR amplification of introns was facilitated by use of YAC pool DNAs rather than total hum an genomic DNA as templates. We then assigned the rp gene STSs to indi vidual human chromosomes by typing human-rodent hybrid cell lines. The genes were placed more precisely on the physical map of the human gen ome by typing of radiation hybrids or screening YAC libraries. fifty-o ne previously unmapped rp genes were localized, and 24 previously repo rted rp gene localizations were confirmed, refined, or corrected. Thou gh functionally related and coordinately expressed, the 75 mapped gene s are widely dispersed: Both sex chromosomes and at least 20 of the 22 autosomes carry one or more rp genes. Chromosome 19, known to have a high gene density, contains an unusually large number of rp genes (12) . This map provides a Foundation For the study of the possible roles o f ribosomal protein deficiencies in chromosomal and Mendelian disorder s.