DIRECT ISOLATION OF HUMAN TRANSCRIBED SEQUENCES FROM YEAST ARTIFICIALCHROMOSOMES THROUGH THE APPLICATION OF RNA FINGERPRINTING

The identification of cDNA clones from genomic regions known to contai n human genes is usually the rate-limiting factor in positional clonin g strategies, We demonstrate here that human genes present on yeast ar tificial chromosomes (YACs) are transcribed in yeast host cells, We ha ve used the arbitrarily primed RNA (RAP) fingerprinting method to iden tify human-specific, transcribed sequences from YACs located in the 13 q12 chromosome region. By comparing the RAP fingerprints generated usi ng defined, arbitrary primers from various fragmented YACs, megaYACs, and host yeast, we were able to identify and map 20 products transcrib ed from the human YAC inserts, This method, therefore, permits the sim ultaneous isolation and mapping of novel expressed sequences directly from whole YACs.