B6.129S-Postn^{tm2.1(cre/Esr1*)Jmol}/J

Stock number: 029645
Product name: Postn^MCM
Research areas: Research Tools

Description

These targeted mutant mice express tamoxifen-inducible cre recombinase from the mouse Postn gene. Expression is restricted to myofibroblasts that have undergone tissue damage (e.g. a myocardial infarction event).

Detailed description

Postn (periostin, osteoblast specific factor) is expressed almost exclusively in myofibroblasts in areas of tissue injury. It is a secreted protein and therefore precludes cell labeling using an antibody-based approach.

These targeted mutant mice express tamoxifen-inducible cre recombinase from the mouse Postn promoter. Heterozygous mice are phenotypically normal, viable and fertile. Some embryonic lethality is seen in homozygotes.

Progeny derived from crosses with floxed stop R26-EGFP fluorescent reporter mice (see Stock No. 012429) that are treated with tamoxifen show less than 1% of interstitial cellular labeling in uninjured heart, skeletal muscle, kidney, lung, liver, and skin. After acute myocardial infarction injury and 1 week of tamoxifen treatment, compound mutant mice demonstrate abundant expression of periostin protein in damaged tissues of the heart.

Development

Tamoxifen-inducible cre recombinase (MerCreMer) cDNA was introduced, in-frame, to the ATG start site of exon 1 via homologous recombination in 129S6/SvEvTac-derived W4 embryonic stem (ES) cells. Resultant male chimeras were crossed with B6.129S4-Gt(ROSA)26Sor^tm1(FLP1)Dym/RainJ mice (see Stock No. 009086) to delete a neomycin cassette. This strain was backcrossed to C57BL/6J for 5 generations by the donating lab (see SNP note below).

A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 43 markers throughout the genome suggested a C57BL/6 genetic background, 1 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

Symbol: Postn^{tm2.1(cre/Esr1*)Jmol}
Name: targeted mutation 2.1, Jeffery Molkentin
MGI accession ID: MGI:5908450
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible; Null/Knockout
Synonyms: Postn^MCM; Postn-MerCreMer
Marker symbol: Postn
Marker name: periostin, osteoblast specific factor
Marker synonyms: A630052E07Rik; OSF2; OSF-2; PDLPOSTN; peri; Periostin; Plf; PN
Chromosome: 3
Strain of origin: 129S6/SvEvTac
Expressed genes: cre/Esr1,Cre recombinase and estrogen receptor 1 fusion gene,
Site of expression: Expression is restricted to myofibroblasts that have undergone tissue damage (e.g. a myocardial infarction event).
Molecular note: Tamoxifen-inducible cre recombinase (MerCreMer: cre recombinase fused to two modified estrogen receptor ligand binding domains at both ends) cDNA was introduced, in-frame, to the ATG start site of exon 1 via homologous recombination. The plasmid also contains a diptheria toxi A cDNA and a FRT-flanked neomycin cassette for negative and positive selection. Flp-mediated recombination removed the FRT-flanked neo cassette.