Experiment
164 markers at an average density of 10cM was used to map QTLs associated with allergen-induced airway hyperresponsiveness (AHR) in a (C3H/HeJ x A/J)F1 x A/J backcross population, and the reciprocal backcross A/J x (C3H/HeJ x A/J)F1. Inbred strain A/J develops a high level of AHR when sensitized and challenged with allergen while inbred strain C3H/HeJ develops a low level of AHR. (C3H/HeJ x A/J)F1 animals exhibit an intermediate phenotype.
Abhr1 and Abhr2 are loci associated with AHR, both mapping to proximal mouse chromosome 2.
Abhr1 maps to a region flanked by D2Mit359 (5 cM) and D2Mit416 (10 cM) giving a peak LOD score of 4.2 at D2Mit416. Gata3 (7 cM), Il2rn (6.4 cM), Mrc1 (5 cM), and Il15ra (6.4 cM) are positional candidate genes in the region of Abhr1. Abhr1 is syntenic to human Chromosome 10p11-p13, 2q12-q14, and 9q22-q34.
Abhr2 maps to a region flanked by D2Mit238 (28 cM) and D2Mit298 (30 cM) giving a peak LOD score of 3.7 at D2Mit298. Hc (23.5 cM), Ptgs1 (29 cM), Ctsb-ps (31 cM), and Lcn2 (27 cM)are positional candidate genes in the region of Abhr2. Abhr2 is syntenic to human Chromosome 9q33-q34 and 2q14-q24.
A suggestive QTL, Abhr3, with a LOD of 1.9 mapped to a region of Chromosome 7 flanked by D7Mit21 (0.5 cM) and D7Mit56 (2.5 cM). Abhr3 is syntenic to human Chromosome 19q13.
Two-way ANOVA detected interaction between Abhr1 and Abhr2, but did not detect interaction between Abhr1 and Abhr3, or between Abhr2 and Abhr3.
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