In this strain, a frameshift mutation was placed into exon 1 and a neomycin resistance (neo) cassette replaces part of exon 3 of the interleukin 3 (Il3) gene, abolishing gene expression. IL-3 is a cytokine that promotes the survival, proliferation, and differentiation of hematopoietic progenitors and mature hematopoietic cells. Homozygous mice are viable and fertile. Bone marrow derived mast cells (BMMC) from IL-3 deficient mice exhibit decreased survival when induced with IgE. Expression of anti-apoptotic proteins, Bcl-xL and Bcl-2 are decreased after IgE-induction. When colony stimulating factor 2 receptor, beta (Csf2rd) is knocked out of these mice, double mutants exhibit a lack of eosinophilic response to parasites, and show a pulmonary alveolar proteinosis-like disease.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype of these C57BL/6J-congenic mice could vary from that originally described on a C57BL/10ScSnJ genetic background. We may modify the strain description if necessary as published results become available.
