Relative resolution of mapped chromosome 7 STSs. As an index of the overall resolution of the physical map reported here, the 36 YAC contigs listed in Table 1 were analyzed by SEGMAP to calculate the percentage of the chromosome residing within various distances around each uniquely ordered STS, performed essentially as described (Olson and Green 1993; Cox et al. 1994). In short, physical bounds of the indicated distances were placed around uniquely ordered STSs present in each computed contig map (i.e., maps depicting the SEGMAP-estimated spacing between STSs). The resulting unique (i.e., nonoverlapping) bounds were then summed and compared to the estimated size of the chromosome (170 Mb). The percentage of the chromosome accounted for by this analysis is indicated for each distance. Shown are the results obtained after mapping the initial 1150 STSs and then after mapping all 2150 STSs.