Experiment
Composite interval mapping (CIM) was used for localization of QTL involved in modulating response to infection with Borrelia burgdorferi. Parental strains C3H/HeN and C3H/HeJ are susceptible to B.burgdorferi-induced arthritis whereas parental strains C57BL/6N and BALB/cAnN are resistant. Four different backcrosses and the reanalysis of a previous intercross were performed.
In the (C57BL/6N X C3H/HeN)F1 X C3H/HeN backcross a novel QTL, Bbaa11, linked to ankle swelling was mapped to Chr 1 at 32.8 cM withmarker D1Mit76, LRT=14.2 accountng for 5% of trait variance. [Table 2.]
In the (C57BL/6N x C3H/HeN) x C57BL/6N backcross a novel QTL, Bbaa12, also mapped to Chr 1. This QTL was also linked to ankle swelling mapping between 92 and 100 cM, LRT=25.1 accounting for 15.1% of the variance. [Table 2.]
In the reanalysis of the (C57BL/6N X C3H/HeN)F2 intercross another QTL was identified.
The authors equate this QTL with Bbaa12 but since Bbaa12 was mapped in the (C57BL/6N x C3H/HeN) x C57BL/6N backcross, which differs from the population of the F2 intercross used here, curators have named this QTL Bbaa30.
Bbaa30 maps to Chr 1 linked to total IgG at 92.3 cM mapping between markers D1Mit150 and D1Mit36, LRT=19.1 accounting of 0.80% variance. [Table 2.]
C3H/HeN-derived alleles are associated withincreased arthritis susceptibility and severity at all QTL mapped in this experiment.
Analysis Tools