Radiation hybrid mapping

Radiation hybrid mapping Now the most rapid method of localizing a gene or DNA fragment to a subregion of a human chromosome and constructing a physical map. 

Nakajima T, Ota N, Kodama T, Emi M. Isolation and radiation hybrid mapping of a highly polymorphic CA repeat sequence at the SREBP cleavage-activating protein (SCAP) locus. J Hum Genet 1999 44 350-351. 

Mapping of eukaryotic chromosomes has involved additional methods which are discussed in Sections E and G,l. These incluse radiation hybrid mapping,104 use of meiotic recombination, identification of restriction fragment length polymorphisms (RFLPs described in Section E,7), and use of expressed sequence tags (ESTs), short DNA sequences deduced from mRNA molecules transcribed from the DNA.105 106... 

Akihito Ozawa, Mark R. Band, Joshua H. I arson, Jena Donovan, Cheryl A. Green, James E. Womack, Harris A. Lewin, Comparative organization of cattle chromosome 5 revealed by comparative mapping by annotation and sequence similarity and radiation hybrid mapping. Proceedings of the National Academy of Sciences USA, 97 (2000), 4150-4155. 

These data can be used to statistically infer the position of chromosomal breaks, and, from that point on, the procedures for map construction are similar to those used in linkage mapping. A map function is used to convert estimates of breakage frequency to additive units of distance measured in centirays (cR), with 1 cR representing a 1% probability that a chromosomal break has occmred between two markers in a single hybrid. The resolution of a radiation hybrid map depends on the size of the chromosomal fragments contained in the hybrids, which in turn is proportional to the amount of irradiation to which the human cell line was exposed. 

Mapview has many useful options, which are well described in the oifline help. Some maps have more than one tier, each displaying different types of markers, such as markers positioned with varying confidence thresholds on a linkage or radiation hybrid map. It is possible to zoom in and out, highlight markers across maps, color code different tiers, display markers using different aliases, change the relative position of the displayed maps, and search for specific markers. To retrieve additional information on a marker from any of the maps, double-click on its name to perform a Simple Search (as described above). A separate browser window will then display the GDB entry for the selected marker. 

Radiation hybrid maps provide an intermediate level of resolution between linkage and physical maps. Therefore, they are helpful for sequence alignment and will aid in completion of the human genome sequencing project. Three human whole-genome panels have been prepared with different levels of X-irradiation and are available for... 

Tonellato, P. J., Zho, H., Chen, D., Wang, Z., Stoll, M., Kwitek-Black, A., and Jacob, H. Comparative Mapping of the Human and Rat Genomes with Radiation Hybrid Maps, RECOMB 99, Lyon, France, April 1999. 

Kim, H. S. (1998). Assignment of the human ARN03 gene (PSCD3) to chromosome 7p21 by radiation hybrid mapping. Ann. Hum. Genet. 62, 551-553. 

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