Table 2 

Comparison of recombination characteristics of RI sets 

RI set 
N strains^{*} 
N typed^{†} 
Total markers 
New markers^{‡} 
Total SDPs 
Total R 
% SDP 
DR 
% DR 
R per strain 


AXBBXA 
37 (28) 
37 (41) 
965 
577 
669 
1775 
37.3% 
114 
12.8% 
43.3 
BXD 
35 (34) 
36 
936 
551 
623 
1492 
41.2% 
95 
12.7% 
41.4 
BXH 
16 (16) 
19 
768 
739 
436 
848 
50.2% 
82 
19.3% 
44.6 
CXB 
13 (13) 
13 
867 
687 
406 
671 
58.8% 
63 
18.8% 
51.6 
BXN 
104 (91) 
109 
1,575 
1,575 
1,220^{§} 
4,786 
25.4% 
354 
14.8% 
43.9 


^{*}Total number of genetically independent strains per RI set genotyped in this study. The numbers in parentheses are numbers of strains available as live stock from the Jackson Laboratory. ^{†}Total number of strains per RI set genotyped in all studies. We genotyped 107 of these 109 strains (BXA9 and BXD41 were not genotyped). Four of the AXBBXA strains are not genetically independent and the effective number of genotyped strains is actually 37 rather than 41. ^{‡}This number includes both newly genotyped markers and makers for which genotypes were changed as a result of retyping. ^{§}Due to overlap of SDPs this number is not a sum of the overlying four values. The total number of unique SDPs was computed from the composite BXN set directly. Total SDPs is the total number of unique strain distribution patterns identified in each set. Total R is our estimate of the total number of independent recombinations (R) represented in each complete set of RI strains, including members of RI sets that are now extinct. This number will underestimate true numbers of recombination breakpoints by about 7.5% due to the limited number of available markers on some chromosome regions. %SDP is our estimate of the percentage of the total number of SDPs that have actually been identified in association with particular markers. DRis the sum of recombinations associated with double recombinant haplotypes (see text) in each RI set. % DR is the percentage of recombinations associated with these double recombinant haplotypes. R per strain is the estimate of the average number of recombination events accumulated by individual RI strains. 

Williams et al. Genome Biology 2001 2:research0046.1research0046.18 doi:10.1186/gb2001211research0046 