QUANTITATIVE LOCUS ANALYSIS OF AIRWAY HYPERRESPONSIVENESS IN A J AND C57BL/6J MICE/

Airway hyperresponsiveness is a key characteristic of human asthma and a marker for asthma-like conditions in animals. F-1 mice derived from A/J and C57BL/6J display a phenotype which resembles the asthma-like phenotype of the A/J mice. Since airway responsiveness failed to segre gate as a mendelian trait, we show significant linkage at two loci, Bh r1 (lod = 3.0) and Bhr2 (lod = 3.7) on chromosomes 2 and 15. A third l ocus, Bhr3 (lod = 2.83), maps to chromosome 17. Each of these loci map s near candidate loci implicated in the pathobiology of asthma. Our st udy represents the first linkages established through a genome-wide su rvey of airway hyperresponsiveness in any mammal.