LINKAGE MAP OF 10 POLYMORPHIC MARKERS ON RAT CHROMOSOME-2

Analysis of F2 intercross progeny of inbred F344/N x LEW/N rats led to the assignment of 10 polymorphic PCR-typable markers to rat chromosom e 2. The markers form a single linkage group covering 47.9 cM with the following order: D2N1R - D2N28 - FGG (gamma fibrinogen) - PKLR (liver and RBC pyruvate kinase) - ATP1A1 (the alpha-1 polypeptide of Na+/Ktransporting ATPase) - HSD3B (hydroxy-delta-5-steroid dehydrogenase) - D2N2R - D2N91 - CAMKI (calmodulin-dependent protein kinase II) - D2N3 5. All but two of the markers D2N1R and D2N2R) were detected using spe cific PCR primers flanking dinucleotide repeats. Sequences with dinucl eotide repeats associated with five genes (FGG, PKLR, ATP1A1, HSD3B, a nd CAMKI) were identified in GenBank, and primers were designed to fla nk these repeats. The PCR primer pairs for three anonymous markers (D2 N28, D2N91, and D2N35) were identified by sequencing cloned LEW/N rat genomic DNA containing (CA)n.(GT)n repeats. D2N1R and D2N2R were ident ified by PCR amplification of genomic DNA with single, nonspecific 10- base oligonucleotide primers. All of the markers were codominant excep t for D2N1R, D2N2R, and CAMKI, which only amplified from F344/N homozy gous and heterozygous rat DNA. The seven codominant markers were highl y polymorphic in 10 other inbred rat strains (SHR/N, WKY/N, MNR/N, MR/ N, LOU/MN, BN/SsN, BUF/N, WBB1/N, WBB2/N, and ACI/N), suggesting that they will be useful for general mapping studies among these strains. C omparative gene mapping analysis indicated that a portion of the mappe d region of rat chromosome 2 exhibits synteny conservation with region s of human chromosome 1 and mouse Chromosome 3.