Correlation between genetic and physical distances for genetic markers. Genetic distances between markers, taken from Gersh et al. (1994),Murray et al. (1994), and Dib et al. (1996) for chromosome 5p, are shown in the first tier of Fig. 2. Physical distances between markers were determined from the location of these markers in the SIGMA map. All genetic markers were localized to the mega-YAC contigs, whereas a subset were localized to breakpoint intervals. Genetic markers D5S1996, D5S631, D5S430, and D5S665 were removed from the plot because of ordering discrepancies with respect to the physical map. Selected genetic markers and the location of the centromere are indicated on the graph for reference.