[Physical mapping of human chromosomes with linking clones and jumping clones]

Physical maps facilitate the correlation of genetic linkage maps and actual genome structure, and contribute to the immediate access to disease genes in question. The introduction of pulsed-field gel electrophoresis (PFGE) made it possible to construct restriction maps in Mb order with rare-cutting enzymes. Linking clones and jumping clones are useful tools for constructing long-range and accurate maps. The linking clones are used to identify adjacent restriction fragments and the jumping clones are to identify neighboring restriction sites. The general strategy for physical mapping using these clones and our application to NotI restriction mapping of human chromosome 21 are described.