Four polymorphic markers on rat chromosome 12 form a single linkage group.

Four PCR-typable polymorphic markers were mapped to rat chromosome 12 by linkage analysis of F2 intercross progeny of Fischer (F344/N) and Lewis (LEW/N) rat strains. The markers formed a single linkage group, covering 27.7 cM, with the following order and distance between markers: plasminogen activator inhibitor (Planh)--0.0 cM--phosphoenolpyruvate carboxykinase-related sequence 2 (Pepckr2)--15.4 cM--anonymous marker (D12N155)--12.3 cM--serine dehydratase (Sdh). All markers were identified and genotyped by PCR analysis of simple sequence repeats. The gene encoding Planh was previously assigned to rat chromosome 12, which allowed us to assign the entire linkage group to this chromosome. These markers were highly polymorphic in 13 additional inbred rat strains (BUF/N, BN/SsN, WKY/N, MNR/N, LER/N, WBB1/N, WBB2/N, MR/N, LOU/MN, SHR/N, ACI/N, SR/Jr, and SS/Jr). These markers should be useful tools for further genetic studies in rats.