These Nfatc1fl/fl mutant mice possess loxP sites flanking exon 3 of the nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1 (Nfatc1) gene. This strain may be useful for osteoclast homeostasis.
Antonios O. Aliprantis, Brigham and Women's Hospital
These Nfatc1fl/fl mutant mice possess loxP sites flanking exon 3 of the nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1 (Nfatc1) gene. Mice that are homozygous for this allele are viable and fertile. NFATC1 is a transcription factor which, when upregulated by the receptor activator for nuclear factor-κB ligand (RANKL), promotes the expression of proosteoclastogenic genes and regulates osteoclast homeostasis. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 3 deleted in cre-expressing tissues.
For example, when crossed to B6.Cg-Tg(Mx1-cre)1Cgn/J mice (Stock No. 003556), poly I:C-induced Cre recombinase in offspring display osteopetrosis, improperly shaped long bones, failure to resorb primary spongiosa, aberrant endochondral growth and ossification.
A targeting vector was designed to insert a single loxP site upstream of exon 3, and a loxP-flanked neomycin resistance (neo) cassette downstream of exon 3 of the nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1 (Nfatc1) gene. The construct was electroporated into C57BL/6-derived embryonic stem (ES) cells. Correctly targeted ES cells injected into C57BL/6 blastocysts and resulting chimeric males were bred with BALB/c females. Offspring were bred with B6.FVB-Tg(EIIa-cre)C5379Lmgd/J transgenic mice (Stock No. 003724) to delete the neo cassette. Progeny contained multiple gene rearrangments; intact floxed-exon 3, intact floxed-neo cassette, or excision of both exon 3 and the neo cassette. Offspring containing only the floxed-exon 3 were crossed to remove the Cre-expressing transgene. The donating investigator reports that these mice were bred C57BL/6 mice for at least 6 generations (see SNP note below). Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.
|Allele Name||targeted mutation 3, Laurie H Glimcher|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Nfatc1, nuclear factor of activated T cells, cytoplasmic, calcineurin dependent 1|
|Strain of Origin||C57BL/6|
|Molecular Note||A loxP site replaced 3 kb of intronic sequence upstream of exon 3 and a floxed neomycin cassette replaced was placed downstream of the exon into a XbaI site. Mice derived from correctly targeted ES cells were crossed with EIIa-cre transgenic mice and progeny were selected by Southern blotting for selective loss of the neomycin resistance cassette. Protein expression was unaffected as determined by immunoblotting of splenocyte extracts. Cre-mediated excision of exon 3 will remove a regulatory domain necessary for proper protein function.|
When maintaining a live colony mice homozygous for the floxed allele may be bred together.
When using the Nfatc1fl mouse strain in a publication, please cite the originating article(s) and include JAX stock #022786 in your Materials and Methods section.