Mice that are homozygous for the mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Screening of third generation mice (G3) on standard chow identified an 8 week old male (born 4/7/2003) with a CBC of 1.50 x 103 WBC/ul (84% lower than controls); testing two weeks later produced a result of 2.51 WBC/ul (74% lower than controls). This mutant mouse strain may be useful in studies of leukopenia.
Following multidose ethylnitrosourea (ENU) treatments to induce mutations in male founder C57BL/6J mice (Stock No. 000664), a forward genetic screen was utilized to identify phenotypic deviants in complex heart, lung, blood, and sleep disorders, at the Mouse Heart, Lung, Blood, and Sleep Disorders (HLBS) Center at The Jackson Laboratory. hlb156 initially was mapped by crossing to C3H/HeJ mice. Mapping identified the location of the mutation in an interval of 14 cM on Chromosome 3, between D3Mit221 and D3Mit224.
Sequencing of the candidate gene Il7, interleukin 7, revealed a T to C transition resulting in a change from leucine to proline at amino acid 15 of the leader signal peptide. Heterozygotes were crossed to generate homozygotes. The mice have been maintained on a C57BL/6J background.
|Allele Name||heart, lung and blood 368|
|Allele Type||Chemically induced (ENU)|
|Gene Symbol and Name||Il7, interleukin 7|
|Strain of Origin||C57BL/6J|
|Molecular Note||A T to C transition resulted in a substitution of leucine to proline at amino acid 15 of the leader signal peptide.|