title: Physical mapping of genes in somatic cell radiation hybrids by comparative genomic hybridization to cDNA microarrays.
abstract: BACKGROUND
  Somatic cell mutants can be informative in the analysis of a wide variety of cellular processes. The use of map-based positional cloning strategies in somatic cell hybrids to analyze genes responsible for recessive mutant phenotypes is often tedious, however, and remains a major obstacle in somatic cell genetics. To fulfill the need for more efficient gene mapping in somatic cell mutants, we have developed a new DNA microarray comparative genomic hybridization (array-CGH) method that can rapidly and efficiently map the physical location of genes complementing somatic cell mutants to a small candidate genomic region. Here we report experiments that establish the validity and efficacy of the methodology.
  
  
  RESULTS
  CHO cells deficient for hypoxanthine:guanine phosphoribosyl transferase (HPRT) were fused with irradiated normal human fibroblasts and subjected to HAT selection. Cy5-labeled genomic DNA from the surviving hybrids containing the HPRT gene was mixed with Cy3-labeled genomic DNA from normal CHO cells and hybridized to a microarray containing 40,185 cDNAs, representing 29,399 genes (UniGene clusters). The DNA spots with the highest Cy5:Cy3 fluorescence ratios corresponded to a group of genes mapping within a 1 Mb interval centered near position 142.7 Mb on the X chromosome, the genomic location of HPRT.
  
  
  CONCLUSIONS
  The results indicate that our physical mapping method based on radiation hybrids and array-CGH should significantly enhance the speed and efficiency of positional cloning in somatic cell genetics.
authors.affiliation: Department of Vascular Biology, The Scripps Research Institute, 10550 N, Torrey Pines Road, La Jolla, CA 92037, USA. Ginsberg@scripps.edu
authors.forename: Johann Y
authors.initials: JY
authors.lastname: Lin
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Pollack
authors.forename: Fan-Li
authors.initials: FL
authors.lastname: Chou
authors.forename: Christian A
authors.initials: CA
authors.lastname: Rees
authors.forename: Allen T
authors.initials: AT
authors.lastname: Christian
authors.forename: Joel S
authors.initials: JS
authors.lastname: Bedford
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Brown
authors.forename: Mark H
authors.initials: MH
authors.lastname: Ginsberg
mesh_terms: D000818:Animals; D016466:CHO Cells / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics*; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism; D005796:Genes / Q000235:genetics*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020161:Physical Chromosome Mapping / Q000379:methods*; D021101:Radiation Hybrid Mapping / Q000379:methods*
chemical_list: D018076:DNA, Complementary; D007041:Hypoxanthine Phosphoribosyltransferase