B6.129S6(129S4)-Tfpi^tm1.1Rdsi/J

Stock number: 017603
Product name: TFPI^Flox
Research areas: Cardiovascular Research, Developmental Biology Research, Hematological Research, Metabolism Research, Neurobiology Research, Research Tools

Description

These mice contain a TFPI^Flox allele with loxP sites flanking exon 4 of the Tfpi gene. When bred to mice that express Cre recombinase, the resulting offspring will have the sequences encoding the Kunitz 1 domain of the TFPI protein deleted in cre-expressing tissues. As the TFPI-K1 domain is necessary for TFPI-inhibition of the tissue factor coagulation pathway, these mice may be useful in generating tissue-specific TFPI deletions for such studies, as well as innate immunity, angiogenesis, and lipid metabolism.

Detailed description

The TFPI^Flox allele has loxP sites flanking exon 4 of the tissue factor pathway inhibitor gene [Tfpi]. Homozygous TFPI^Flox mice are viable and fertile with no observed abnormalities. When bred to mice that express Cre recombinase, the resulting offspring will have the sequences encoding the Kunitz 1 domain of TFPI protein (TFPI-K1) deleted in the cre-expressing tissues. This is designed to result in a K1-deleted form of TFPI containing the remainder of the TFPI protein (and to affect all K1-containing isoforms including TFPIα, TFPIβ, and TFPIγ).

For example, when TFPI^Flox mice are bred to a strain expressing Cre recombinase in embryonic tissues (CMV-Cre; see Stock No. 006054), the resulting mice with pan deletion of the TFPI-K1 domain exhibit complete prenatal lethality; this is similar to mice homozygous for the TFPI knockout allele.

In addition, when TFPI^Flox mice are bred to a strain expressing Cre recombinase in endothelial cells (Tie2-Cre; see Stock No. 004128), the resulting TFPI^Tie2 homozygous mice are viable and fertile with deletion of TFPI-K1 in both endothelial and hematopoietic (bone marrow/blood cell) lineages. Such deletion reduces TFPI activity in plasma approximately 70% and renders mice more susceptible to ferric chloride-induced arterial thrombosis.

Of note, when TFPI^Flox mice are bred to LysM-Cre mice (see Stock No. 004781 for example), the resulting TFPI^LysM mice are viable and fertile with deletion of TFPI-K1 in myelomonocytic lineage cells (monocytes, macrophages, and granulocytes). Such deletion reduces TFPI activity in plasma approximately 19% and mice show no effect on susceptibility to ferric chloride-induced arterial thrombosis compared to wildtype.

Development

A targeting vector was designed to insert an frt-flanked PGK-neo cassette and a loxP site just upstream of exon 4, and a second loxP site just downstream of exon 4 of the targeted gene. The construct was electroporated into 129S6/SvEvTac-derived TL1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts and chimeric males were bred with C57BL/6J females to establish the TFPI^{Flox pGK-NEO} colony. To remove the frt-flanked PGK-neo cassette, the TFPI^{Flox pGK-NEO} mice were then bred to mice expressing FLP1 recombinase (129S4 genetic background; see Stock No. 003946). The resulting mice with single frt site and first loxP site remaining upstream of exon 4, and a second loxP site downstream of exon 4 were identified. These TFPI^Flox mice were subsequently backcrossed to C57BL/6J mice for at least nine generations prior to sending to The Jackson Laboratory Repository. Upon arrival, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Tfpi^tm1.1Rdsi
Name: targeted mutation 1.1, Robert D Simari
MGI accession ID: MGI:4836740
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Tfpi
Marker name: tissue factor pathway inhibitor
Marker synonyms: A630013F22Rik; EPI; LACI; TFI; TFPI1
Chromosome: 2
Strain of origin: 129S6/SvEvTac
Molecular note: A FRT flanked Neomycin cassette was inserted within intron 3 and exon 4 was floxed by homologous recombination. The selection cassette was removed by flp mediated recombination.