The Mig-6flox allele has loxP sites flanking exons 2-4 of the mitogen-inducible gene-6 locus (Effri1; Mig-6). Removal of the floxed sequence creates a null allele. These mice may be useful in studying joint physiology/homeostasis and osteoarthritis, as well as stress response, lung development and tumor suppression.
George Vande Woude, Van Andel Research Institute
The mitogen-inducible gene-6 (Mig-6 ; Errfi1) is an immediate early response gene encoding a scaffolding adaptor protein that functions as a tumor suppressor, is involved in developmental and physiological processes (skin morphogenesis and lung development) and is essential for postnatal synovial joints physiology.
The Mig-6flox allele has loxP sites flanking exons 2-4 of the mitogen-inducible gene-6 locus. Mice homozygous for the floxed allele (Mig-6flox/flox) are viable and fertile with no reported abnormalities. When bred to mice that express Cre recombinase, the resulting offspring will have absence of Mig-6 function in cre-expressing tissues. Examples listed below.
When bred to germline Cre-expressing mice (Stock No. 006054; B6.C-Tg(CMV-cre)1Cgn/J), the resulting global Mig-6 deletion has no transcript expression from the mutant allele (evaluated in liver and thymus). Homozygous null mice develop an early-onset osteoarthritis-like degenerative joint disease. Specifically, several joints (including the knee, ankle and temporal mandibular joints) become enlarged, articular cartilage degrades, and bony nodules appear within the affected joints. Homozygous null mice are viable but born at ~half of expected Mendelian frequency, with most surviving homozygotes dead by six months of age.
Additionally, when Mig-6flox mice are bred to Col2a1-cre transgenic mice (Stock No. 003554; B6;SJL-Tg(Col2a1-cre)1Bhr/J), the resulting animals with homozygous Mig-6-deficiency in chondrogenic cells have an osteoarthritis-like phenotype primarily in the knee joint (rarely other joints), with a majority of the mice living more than one year.
The Mig-6flox allele (Errfi1tm3.1Gvw) was created by Dr. George Vande Woude (Van Andel Research Institute). The targeting vector was designed to have a loxP site and frt-flanked PGK-neo cassette upstream of exon 2, and a second loxP site just downstream of exon 4 of the ERBB receptor feedback inhibitor 1 gene (Errfi1 ; also called mitogen-inducible gene-6 [Mig-6]) on chromosome 4.
The construct was electroporated into 129S1/Sv-Oca2+ Tyr+ Kitl+-derived CJ7 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric males were bred with "129SV" females for germline transmission to establish the Mig-6Tar colony.
Offspring were bred with FLPeR mice (on an undisclosed genetic background; from Stock No. 003946 129S4/SvJaeSor-Gt(ROSA)26Sortm1(FLP1)Dym/J) for germline deletion of the neo cassette; resulting in the Mig-6flox allele (loxP::frt:;exons 2-4::loxP).
The Mig-6flox colony was bred with FVB/NJ wildtype mice for ten generations (and the Flp-expressing allele was removed), and then heterozygous mice were bred together to make homozygotes. In 2015, sperm from homozygous males with albino coat color was frozen at Van Andel Research Institute. In 2016, some of that frozen sperm was sent to The Jackson Laboratory Repository.
To establish our live colony, an aliquot of frozen sperm was used to fertilize FVB/NJ oocytes (Stock No. 001800).
Of note, it is not known if the Y chromosome has been fixed to the FVB/NJ background during backcrossing.
|Allele Name||targeted mutation 3.1, George F Vande Woude|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Errfi1, ERBB receptor feedback inhibitor 1|
|Strain of Origin||129S1/Sv-Oca2+ Tyr+ Kitl+|
|Molecular Note||A loxP-FRT-Neo-FRT-exons 2 to 4-loxP cassette was inserted. FLP-mediated recombination removed the neo cassette, leaving the exons 2 to 4 flanked by loxP sites.|
When maintaining a live colony, heterozygous mice may be bred together, to wildtype mice from the colony or to FVB/NJ inbred mice (Stock No. 001800). Alternatively, homozygous mice may be bred together. Mice homozygous for the floxed allele (Mig-6flox/flox) are viable and fertile with no reported abnormalities.
When using the Mig-6flox mouse strain in a publication, please cite the originating article(s) and include JAX stock #028795 in your Materials and Methods section.