Radiation Hybrid Mapping: A Somatic Cell Genetic Method for Constructing High-Resolution Maps of Mammalian Chromosomes

Abstract

Radiation hybrid (RH) mapping, a somatic cell genetic technique, was developed as a general approach for constructing long-range maps of mammalian chromosomes. This statistical method depends on x-ray breakage of chromosomes to determine the distances between DNA markers, as well as their order on the chromosome. In addition, the method allows the relative likelihoods of alternative marker orders to be determined. The RH procedure was used to map 14 DNA probes from a region of human chromosome 21 spanning 20 megabase pairs. The map was confirmed by pulsed-field gel electrophoretic analysis. The results demonstrate the effectiveness of RH mapping for constructing high-resolution, contiguous maps of mammalian chromosomes.

Oat–maize chromosome addition lines: A new system for mapping the maize genome

“…Radiation hybrids (derivative cell lines from irradiated somatic cell hybrids) are an attractive alternative for cloning subfragments of a chromosome. Irradiation to produce chromosome breakage and segregation of genetic material has been applied to a number of mammalian somatic cell hybrids containing individual alien chromosomes (10). A disadvantage of this approach in some cases is that a host genome and an alien chromosome have too many in-common nucleotide sequences, thus making difficult the direct analysis, identification, and isolation of the alien chromosome fragments.…”

“…Alien chromosome additions have been used for gene mapping (2,6,7) and serve as an enriched source of markers for positional cloning and constructing physical maps of specific chromosomes. The discovery of maize-chromosome retention in oat ''haploids'' after oat ϫ maize crosses and the recovery of stable maize chromosome-addition oat lines (8,9) should allow the development of a system of chromosome analysis similar to that available in mammalian hybrid-cell systems (10)(11)(12). Such a system may be used for gene assignment, isolation of chromosome-specific probes (13), flow sorting (14) and microdissection of chromosomes (15), development of chromosomespecific ''paints'' of fluorochrome-labeled DNA fragments (16)(17)(18), physical mapping, and selective isolation and mapping of cDNAs of a particular chromosome (19,20).…”

Divergent Human Y-Chromosome Microsatellite Evolution Rates

“…Each cell line was analyzed by PCR amplification and the products were resolved on 6% polyacrylamide gels and silverstained. The second approach made use of the Stanford G3 humanhamster radiation hybrid somatic cell panel (Cox et al 1990;Stewart et al 1997), which was purchased from Research Genetics (Huntsville, AL, USA). The amplification products were resolved using a denaturing 6% polyacrylamide gel on the ALFExpress sequencer (Pharmacia).…”

Toward a Complete Human Genome Sequence

“…These markers were initially taken from the available YAC maps (for chromosomes 2, 7, 22, and X) and were supplemented with all other markers in the public domain. For chromosomes 1, 6, and 20, markers derived from ESTs (Hillier et al 1996) and flow-sorted chromosomes (Ross and Langford 1997) were used together with existing markers to assemble integrated maps by RH mapping (Cox et al 1990;Walter et al 1994;Mungall et al 1996) (maps are available at http://www.sanger.ac.uk/HGP/ Rhmap). The bacterial clones are assembled into contigs by comparative restriction fingerprint analysis (Coulson et al 1986;Olson et al 1986;Gregory et al 1997;Marra et al 1997) and landmark content mapping (Green and Olson 1990).…”