STOCK F3^tm1Nmk/J

Stock number: 028721
Product name: TF^flox
Research areas: Cancer Research, Cardiovascular Research, Developmental Biology Research, Neurobiology Research, Research Tools

Description

The TF^flox floxed allele has loxP sites flanking exon 1 of the coagulation factor III gene (F3; tissue factor [TF], thromboplastin or CD142). Removal of the floxed sequence creates a null allele. These mice may be useful in studying deficiency of the primary activator of the blood coagulation cascade.

Detailed description

The coagulation factor III gene (F3; tissue factor [TF], thromboplastin or CD142) encodes a cell surface glycoprotein that is the primary activator of the blood coagulation cascade.

The TF^flox allele has loxP sites flanking exon 1 of the coagulation factor III gene. Mice homozygous for the floxed allele are viable and fertile with no reported abnormalities.

When bred to mice that express Cre recombinase, the resulting offspring will have TF RNA (and functional TF protein expression) deleted in cre-expressing tissues.

For example, when bred to germline Cre-expressing mice (EIIa-Cre; Stock No. 003724), the resulting TF global knockout homozygotes die in utero.
TF^flox mice allow studying cell/tissue-specific TF deficiency in myeloid cells (LysM-Cre ; Stock No. 004781), megakaryocytes and platelets (Pf4-iCre; Stock No. 008535), vascular smooth muscle (SM22-Cre; see Stock No. 017491) and hepatocytes (Alb-Cre; Stock No. 003574).
In addition, breeding TF^flox mice to Tie2-Cre transgenic mice (Stock No. 008863) results in offspring with TF deficiency in both endothelial cells and hematopoietic cells. Such mice may also be useful in studying sickle cell anemia in the Townes model (Stock No. 013071).

Development

The TF^flox floxed allele was created by Dr. Nigel Mackman (while at The Scripps Research Institute, now at University of North Carolina at Chapel Hill). First, a targeting vector was designed to have a loxP site upstream of exon 1, and a second loxP site followed by an frt-flanked neo cassette just downstream of exon 1 of the coagulation factor III gene (F3; tissue factor [TF], thromboplastin or CD142) on chromosome 3.

The construct was electroporated into 129S6/SvEv-derived CMTI-1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric males were bred with C57BL/6J females for germline transmission and to establish the TF^floxneo colony.

TF^floxneo mice were bred with ACTB-Flpe-transgenic mice (on an undisclosed genetic background) for germline deletion of the neo cassette.

The resulting TF^flox mice were bred with C57BL/6J wildtype mice for ~3-4 generations (and the Flp-expressing transgene was removed) prior to sending males to The Jackson Laboratory Repository in 2016.

Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Of note, it is not known if the Y chromosome has been fixed to the C57BL/6J background during backcrossing.

Allele

Symbol: F3^tm1Nmk
Name: targeted mutation 1, Nigel Mackman
MGI accession ID: MGI:3803978
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: F3
Marker name: coagulation factor III
Chromosome: 3
Strain of origin: 129S6/SvEvTac
Molecular note: A loxP site was inserted upstream of exon 1 and an frt-flanked neo cassette with a 5' loxP site was inserted downstream of exon 1. Germ line, flp-mediated reombination was used to remove the neo cassette leaving exon 1 floxed.