A GENETIC-LINKAGE MAP OF THE LABORATORY RAT, RATTUS-NORVEGICUS

We report the construction of the first complete genetic linkage map o f the laboratory rat. By testing 1171 simple sequence length polymorph isms (SSLPs), we have identified 432 markers that show polymorphisms b etween the SHR and BN rat strains and mapped them in a single (SHR x B N) F-2 intercross. The loci define 21 large linkage groups correspondi ng to the 21 rat chromosomes, together with a pair of nearby markers o n chromosome 9 that are not linked to the rest of the map. Because 99. 5% of the markers fall into one of the 21 large linkage groups, the ma ps appear to cover the vast majority of the rat genome. The availabili ty of the map should facilitate whole genome scans for genes underlyin g qualitative and quantitative traits relevant to mammalian physiology and pathobiology.