Mapping Data

Experiment

• Experiment
  TEXT-QTL-Candidate Genes
• Chromosome
  2
• Reference
  J:108211 Karp CL, et al., Identification of complement factor 5 as a susceptibility locus for experimental allergic asthma. Nat Immunol. 2000 Sep;1(3):221-6
• ID
  MGI:3623803

Genes

Gene	Assay Type
Abhr2	visible phenotype
Hc	reported elsewhere

Notes

• Experiment
  Abhr2 (allergen induced bronchial hyperresponsiveness 2) is a previously identified QTL at approximately 30 cM on mouse Chromosome 2. Gene expression microarray analysis of lung RNA extracted from sensitive high-responder strain A/J and resistant low-responder strain C3H/HeJ, as well as low- and high-responding (A/J x C3H/HeJ)F1 x A/J backcross animals. Twenty-one differentially expressed genes were identified one of which, Hc (formerly C5), mapped near Abhr2 at 23.5 cM on chromosome 2. Hc mRNA expression patterns correlated with bronchial hyperresponsive phenotype- A/J and high-responder backcross animals exhibit high Hc expression whereas C3H/HeJ and low-responder backcross animals exhibit low Hc expression. In addition, Hc genotype also correlated with severity of bronchial hyperresponsiveness in backcross animals. Homozygosity for A/J-derived alleles at Hc was associated with high responsiveness while heterozygosity at Hc was associated with low responsiveness.
  
  Hc SNP analysis revealed a 2 bp deletion in the sensitive A/J strain resulting in deficient Hc mRNA and protein production. Resistant strain C3H/HeJ does not have this mutation and produces functional Hc mRNA and protein. This SNP was screened in other inbred strains with known bronchial hyperresponsive phenotypes. The 2 bp Hc deletion was observed in sensitive strains AKR/J and A/J, but not in resistant strains C57BL/6J, BALB/cJ, and C3H/HeJ.