ALIGNMENT OF THE PIGMAP AND USDA LINKAGE MAPS OF PORCINE CHROMOSOME-2AND CHROMOSOME-5

The PiGMaP and USDA porcine linkage maps for chromosomes 2 and 5 have been aligned by typing five USDA microsatellite markers from chromosom es 2 and 4 from chromosome 5 on the PiGMaP reference families. The mar kers in the two maps can be successfully aligned except for Sw395 on c hromosome a, which is the endmost marker in the USDA map 22 cM remote from the next marker, but which maps to a more central location and in the same position as Sw776 in the PiGMaP families. The mapping of fou r additional chromosome 5 markers has enabled amalgamation of the two previously separate PiGMaP linkage groups assigned to chromosome 5 and has more than doubled the length of its map. The USDA map of chromoso me 5 is considerably shorter than the revised PiGMaP version, particul arly between DAGK and Sw1071, where the corresponding lengths are 9 cM versus 33 cM.