These IL-7Rfl mutant mice have loxP sites flanking exon 3 and may be useful in generating conditional mutations for studying immune system homeostasis and lymphocyte development and maturation.
Alfred Singer, National Cancer Institute, National Institutes of Health
The IL7 receptor is important in the regulation of T, B, and NK lymphoid cell development. The Il7r, interleukin 7 receptor, gene encodes a subunit of the IL-7 receptor, which is essential for T cell development and V(D)J recombination. These IL-7Rfl mice possess loxP sites flanking exon 3 of the targeted gene. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 3 deleted in the cre-expressing tissues.
When bred to a strain with Cre recombinase expression in preselection double positive thymocytes, this mutant mouse strain may be useful in studies of T cell population subset differentiation in the thymus.
A targeting vector designed by Dr. Alfred Singer (National Cancer Institute, National Institutes of Health) containing a FRT- and loxP-flanked neo cassette was inserted downstream of exon 3. A second loxP site was inserted upstream of exon 3. The construct was electroporated into unspecified 129 derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were bred to female Actin-Flp recombinase expressing transgenic mice (on the C57BL/6 background) to remove the neo cassette and left exon 3 floxed, with a single FRT site downstream of exon 3. The mice were then crossed to C57BL/6 mice for approximately 3 generations. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 1.1, Alfred Singer|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Il7r, interleukin 7 receptor|
|Strain of Origin||129|
|Molecular Note||A loxP site was inserted upstream of exon 3. An FRT- and loxP-flanked neo cassette was inserted downstream of exon 3. Flp-mediated recombination removed the neo cassette and left exon 3 floxed.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the IL-7Rfl mouse strain in a publication, please cite the originating article(s) and include JAX stock #022143 in your Materials and Methods section.