Submitted to: Dekker Encyclopedia of Plant and Crop Science
Publication Type: Book / Chapter
Publication Acceptance Date: 12/2/2002
Publication Date: N/A
Technical Abstract: Radiation hybrid maps are physical maps of genomes that provide an alternative to traditional genetic maps. These radiation hybrid maps have two important advantages over genetic maps. First, distances on a radiation hybrid map are determined by the frequency of radiation-induced breaks between markers. The distribution of breaks is believed to be random; therefore, calculated distances along a radiation hybrid map are proportional to physical distances. Second, markers need not be polymorphic for mapping on a radiation hybrid map. Any DNA sequence of interest is readily mapped. High quality maps produced by radiation hybrid mapping have proven their worth in human genome project with over 30,000 sequences mapped. A somewhat analogous radiation hybrid mapping system is being developed for the physical mapping of the maize genome except this plant system involves whole plants instead of cell culture lines. The starting materials here were oat-maize addition lines containing a single maize chromosome in an oat background. Radiation hybrid lines were selected from among the progeny of irradiated oat-maize addition lines. With a few of these lines, markers may be quickly localized to a chromosome segment. The results suggest that radiation hybrid mapping can become a useful genomics tool in at least certain plant systems as it is in several animal systems.