Chromosomal Assignments of Novel Genes Expressed in

By collecting 3'-directed cDNA sequences called gene signatures (GSs) on a large scale, it is possible to make an expression profile of genes in a particular tissue, as well as discovering a number of novel genes. A total of 305 novel GSs collected from granulocytoid cells derived from HL60, a human promyelocytic leukemia cell line, by exposure to dimethyl sulfoxide were radiolabeled and used for Southern blot analyses to determine the copy number of the corresponding genes. Of these, 198 GSs identified as representing single-copy genes were then used as probes for hybridization analyses using a monochromosomal hybrid cell DNA panel. Sixty-nine of them were assigned to individual chromosomes. These results demonstrate that the chromosomal distribution of the GSs seems not to be proportional to the cytogenetic length of each chromosome. Key words: gene signature; HL60; granulocytes; chromosome assignment 1