STOCK Vip^{tm2.1(flpo)Zjh}/J

Stock number: 028578
Product name: VIP-ires-Flp
Research areas: Neurobiology Research, Research Tools

Description

VIP-ires-Flp knock-in mice have Flp Recombinase expression in GABAergic neurons derived from the caudal-ganglionic eminence (CGE), as directed by the endogenous vasoactive intestinal polypeptide promoter. These mice are useful for studying the fate of progenitor cells at the VIP/CR intersection.

Detailed description

VIP-ires-Flp knock-in mice express Flp Recombinase from the endogenous vasoactive intestinal polypeptide (Vip) promoter/enhancer elements. VIP expressing cells are GABAergic neurons derived from the caudal-ganglionic eminence (CGE). They represent up to 15% of all cortical interneurons. Homozygous mice are viable and fertile. FLP is detected in the neocortex, hippocampus, olfactory bulb, suprachiasmatic nuclei, and other discrete midbrain and brainstem regions. As such, when VIP-ires-Flp mice are bred with mice containing frt-flanked sequence(s), Flp-mediated recombination will result in deletion of the flanked sequence(s) in the Vip-expressing cells of the offspring.

These mice were bred to Ai65(RCFL-tdT)-neo mice (Stock No. 021875) (after removal of the loxP-flanked STOP codon by breeding with CR(calretinin)-ires-cre mice (Stock No. 010774)) in order to study the fate of progenitor cells at the VIP/CR intersection. tdTomato-labeled cells in layer 2/3 show vertically oriented bipolar morphology with irregular spiking (IS) patterns.

In contrast, when Ai65(RCFL-tdT)-neo mice were first bred with CCK(cholecystokinin)-ires-Cre mice (Stock No. 012706) many of these cells show branched local axon arbors within layer 2/3, with multipolar axon dendrites extended to layer 1, with either bursting or fast-adapting firing patterns, which are infrequently observed in VIP/CR cells.

Development

A targeting vector was designed to insert an internal ribosome entry site (IRES) fused to Flpo Recombinase gene (a codon-optimized FLPe gene modified for translation in mammalian cells and higher recombination efficiency in cells and in mice), followed by a loxP-flanked neo cassette, downstream of the stop codon of the vasoactive intestinal polypeptide (Vip) gene. This construct was electroporated into (C57BL/6 x 129S4/SvJae)F1-derived V6.5 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts and chimeric mice were bred with B6.C-Tg(CMV-cre)1Cgn/J mice (Stock No. 006054) to remove the neo selection cassette. Resulting mice were bred to C57BL/6J mice to remove the Cre-expressing transgene, and offspring were subsequently bred together to create a homozygous colony of VIP-ires-Flp mice. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Vip^{tm2.1(flpo)Zjh}
Name: targeted mutation 2.1, Z Josh Huang
MGI accession ID: MGI:5700390
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Vip
Marker name: vasoactive intestinal polypeptide
Chromosome: 10
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: FLP,FLP recombinase,Saccharomyces cerevisiae
Site of expression: FLP Recombinase is expressed in the neocortex, hippocampus, olfactory bulb, suprachiasmatic nuclei, and other discrete midbrain and brainstem regions.
Molecular note: The targeting vector is designed to insert an internal ribosome entry site (IRES) fused to flpo recombinase gene (a codon-optimized flpe gene modified for translation in mammalian cells and higher recombination efficiency in cells and in mice), followed by a loxP-flanked neo cassette, downstream of the stop codon of the gene. Cre-mediated recombination removed the floxed neo cassette.