Mice homozygous for the Irf8 knockout allele (Irf8-/-) may be useful in studying immunodeficiency (abnormal populations of B cells, T cells, granulocytes and macrophages), hematopoiesis, lymphoma and human chronic myeloid leukemia.
IMR Colony, The Jackson Laboratory
Herbert C. Morse III, Laboratory of Immunopathology, NIAID, NI
Andrew P McMahon, University of Southern California
Mice homozygous for this Irf8 knockout allele (Irf8-/-) may be expected to to exhibit some or all of the phenotype published for other Irf8 null mutations on both a C57BL/6J-congenic and mixed genetic background. For example, other Ifr8 null mice are viable and fertile as young animals. Homozygotes are immunodeficient (abnormal populations of B cells, T cells, granulocytes and macrophages) and develop a syndrome similar to human chronic myeloid leukemia. Acute onset begins by 10 weeks of age, progresses through chronic stage (~20 weeks of age), and significant mortality by ~50 weeks of age.
In an attempt to offer knockout versions of conditional alleles, The Jackson Laboratory Repository bred floxed mice (Stock No. 014175) with germline-expressing Cre recombinase mice (Stock No. 008454). The resulting animals with pan deletion of the floxed exons (Irf8-/-) are available as Stock No. 018298. It should be noted that the phenotype of these homozygous knockout mice could vary from that published/described for other knockout mice established in different laboratories or on different genetic backgrounds. We may modify our strain description if necessary as results become available.
The Irf8f targeted mutation was designed by Dr. Herbert C. Morse III (National Institute of Allergy and Infectious Diseases) to have loxP sites on either side of exon 2 of the interferon regulatory factor 8 gene. In 2011, Irf8f mice on a C57BL/6 genetic background were sent to The Jackson Laboratory Repository as Stock No. 014175. Upon arrival, some Irf8f mice were bred with B6.Cg-Tg(Sox2-cre)1Amc/J mice (Stock No. 008454) for germline removal of floxed exon 2. Offspring with pan deletion of floxed exon 2 were identified and then selectively bred to C57BL/6J inbred mice (Stock No. 000664) to remove the Cre transgene. The resulting mice, heterozygous for the Irf8-deficient allele (Irf8-), were subsequently bred together, to wildtype mice from the colony, or to C57BL/6J inbred mice to establish Stock No. 018298.
|Allele Name||targeted mutation 1.2, Herbert Morse III|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Irf8, interferon regulatory factor 8|
|Strain of Origin||B6.Cg-Thy1a|
|Molecular Note||Exon 2 was floxed. Cre-mediated recombination removed exon 2.|
When maintaining a live colony, heterozygous mice may be bred together, to wildtype mice from the colony, or to C57BL/6J inbred mice (Stock No. 000664).
When using the Irf8- mouse strain in a publication, please cite the originating article(s) and include JAX stock #018298 in your Materials and Methods section.