Experiment
Linkage analysis was performed on 559 proteoglycan-immunized (BALB/cCrl x DBA/2Crl)F2 animals to detect QTLs associated with arthritis susceptibility, severity, and onset. BALB/cCrl females are 100% susceptible to proteoglycan-induced arthritis (PGIA) whereas DBA/2Crl males are resistant. F1 hybrid males and females are also resistant to PGIA.
Several previously identified PGIA loci were confirmed in this study. These include Pgia1, Pgia4, Pgia6, Pgia7 Pgia8, Pgia9, Pgia12.
The authors cite the following marker as having been previously mapped; however, differing parental strains were used in the previous map studies. We have renamed the QTL as follows:
The authors refer to Pgia25 on mouse chromosome X. This QTL was originally mapped using (BALB/cCrl xDBA/1J)F2 mice in J:82018. We have renamed this QTL, mapped here using (BALB/cCrl x DBA/2Crl)F2 mice, as Pgia39. This QTL maps to mouse chromosome X at DXMit5 with LOD=3.0 for disease onset for all F2 mice. The Pgia39 interval spans 67-72cMs on chr X.
Interaction was detected between Pgia6 on mouse Chromosome 10 and Pgia39 on mouse Chromosome X. Heterozygosity at Pgia6 in conjunction with DBA/2Crl-derived allele at Pgia39 conferred lower arthritis onset and incidence (susceptibility).
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