Fig. 1.

Whole-genome scan for linkage to arthritis severity in the pedigree. (a) Young adult BALB/cJ or SJL/J mice were challenged with serum from arthritis K/BxN donors, and the progression of arthritis was tracked as thickening of the ankle joint over time. (b) Marker/trait association score derived from combined information in different generations. Significance (-log10 of the P value) was derived from the frequency of observing by chance the same association metrics for unlinked markers segregating randomly through 10,000 simulated pedigrees of identical structure. (c) Selected logarithm of odds scores from the transmission disequilibrium test, for association to the different metrics of arthritis severity (onset, maxAT, or composite “severity index”). Light and dark shading denotes suggestive and significant association. Only the regions with suggestive or significant association are shown here; full data are in Table 2, which is published as supporting information on the PNAS web site.