SELECTION OF CDNAS USING CHROMOSOME-SPECIFIC GENOMIC CLONES - APPLICATION TO HUMAN-CHROMOSOME-13

We have developed a general method for an masse isolation of cDNAs pre sent in a normalized library by hybridization to arrayed chromosome-sp ecific phage lambda clones; we have used this approach to initiate exo n-mapping of human chromosome 13. An advantage of the simultaneous iso lation of cDNA/lambda pairs is that it allows cytogenetic assignment o f a bona fide genomic clone by in situ hybdridization, which also veri fies that the corresponding cDNA or a homologous expressed sequence re sides on chromosome 13. This information is enriched by partial sequen cing of a selected cDNA from both ends. The sequence of the 3' noncodi ng region provides an 'identifier' that is used to develop STSs, while the sequence from the 5' end, often corresponding to a coding region, is used for homology searches in databases that occasionally reveal g ene functions.