B6.129S4-Gt(ROSA)26Sor^tm1(FLP1)Dym/RainJ

Stock number: 009086
Product name: ROSA26::FLPe knock in
Research areas: Research Tools

Description

This FLP deleter strain may be useful for generating frt-FLP conditional mutations and serves as a source of FLP1-expressing primary cell lines.

Detailed description

Homozygous FLPeR mice are viable and fertile, with widespread expression of the FLPe variant of the Saccharomyces cerevisiae FLP1 recombinase gene driven by the Gt(ROSA)26Sor promoter. The FLPe recombinase variant exhibits enhanced thermostability with recombination activity being four-fold and ten-fold that of wild type FLP at 37C and 40C, respectively. The Gt(ROSA)26Sor promoter drives expression from preimplantation onward and extensive target gene recombination can be achieved in most tissue types, including cells of the developing germ line. The knock-in construct also includes a neomycin resistance gene driven by the mouse phosphoglycerate kinase promoter (PGK neo) and polyadenylation signal sequence. When bred with mice containing a frt-flanked sequence of interest, FLP-mediated recombination will result in deletion of the frt-flanked sequence(s) in the offspring. This FLP deleter strain may be useful for generating frt-FLP conditional mutations and serves as a source of FLP1-expressing primary cell lines.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

 

Development

The R26^Fki knock-in construct was designed by Dr. Susan M. Dymecki (Harvard Medical School) by first inserting a FLPe cassette into a ROSA26 knock-in vector. This construct also includes a neomycin resistance gene driven by the mouse phosphoglycerate kinase promoter (PGK neo) and polyadenylation signal sequence. The R26^Fki knock-in construct was electroporated into 129S4/S4JaeSor-derived AK7 embryonic stem (ES) cells, thereby disrupting the Gt(ROSA)26Sor locus. Correctly targeted ES cells were utilized to generate chimeras.

Homozygous males from The Jackson Laboratory strain 129S4/SvJaeSor-Gt(ROSA)26Sor^tm1(FLP1)Dym/J (Stock No. 003946) were purchased by Elaine W. Raines and Carole L. Wilson (University of Washington School of Medicine). There, mutant males were backcrossed to C57BL/6J inbred females (see Stock No. 000664) for ten generations and then made homozygous prior to sending to The Jackson Laboratory as Stock No. 009086. The Y chromosome may not have been fixed to the genetic background during the backcross.

Allele

Symbol: Gt(ROSA)26Sor^tm1(FLP1)Dym
Name: targeted mutation 1, Susan Dymecki
MGI accession ID: MGI:2429412
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Chromosome: 6
Strain of origin: 129S4/SvJaeSor
Expressed genes: FLP,FLP recombinase,Saccharomyces cerevisiae
Site of expression: constitutive expression of FLP1 recombinase from preimplantation onward and in most tissue types (including cells of the developing germ line)
Molecular note: An enhanced flp cassette containing a splice acceptor site was ligated to a downstream PGK-neo cassette and inserted at the endogenous locus. Efficient frt-specific recombination in transgenic mice carrying a reporter gene was reported to reflect constituitive expression of the Gt(ROSA)26Sor from preimplantation onward.