B6;129S4-Eomes^{tm1.1(cre/ERT2)Zjh}/J

Stock number: 036301
Product name: Tbr2-2A-CreER
Research areas: Neurobiology Research, Research Tools

Description

Tbr2-2A-CreER knock-in mice express tamoxifen-inducible CreERT2 fusion protein from the mouse Eomes (eomesodermin; also called Tbr2) promoter in EOMES-positive cortical glutamatergic pyramidal neurons (PyNs).

Detailed description

Tbr2-2A-CreER knock-in mice express a CreER^T2 (CreERT2) fusion protein from the Eomes (eomesodermin; also called Tbr2) promoter/enhancer elements. CreERT2 fusion gene activity is inducible and observed following tamoxifen administration. As such, when Tbr2-2A-CreER mice are bred with mice containing loxP-flanked sequence(s), tamoxifen-inducible Cre-mediated recombination will result in deletion of the floxed sequence(s) in EOMES-positive cortical glutamatergic pyramidal neurons (PyNs). No other tissues were tested for Cre recombinase activity.

The donating investigator reports that there is no Cre recombinase activity before tamoxifen treatment. Endogenous Eomes gene expression is not altered by the knock-in insert. Homozygous mice are viable and fertile.

A set of temporally inducible mouse Cre and Flp knock-in driver lines that enable combinatorial targeting of major progenitor types and projection classes of glutamatergic pyramidal neurons (PyNs) and their progenitors were described in Matho et al, 2020 (BioRxiv). These gene knock-in's recapitulate the endogenous spatial, temporal and cellular expression patterns of transcription factors and effector genes. Several of these strains are available through The Jackson Laboratory:

Driver Lines:
Lhx2-2A-CreER 036293
PlexinD1-2A-CreER 036294
PlexinD1-2A-flpO 036295
Fezf2-2A-CreER 036296
Fezf2-2A-flpO 036297
Tle4-2A-CreER 036298
Tbr1-2A-CreER 036299
Cux1-2A-CreER 036300
Tbr2-2A-CreER 036301
Tis21-2A-CreER 036303
Adcyap1-2A-CreER 033999
Tcerg1l-2A-CreER 034000

Reporter Line:
4 Dual-tTA 036304

Development

A targeting vector was designed to insert CreER^T2 and a T2A self-cleaving peptide sequence followed by a frt-flanked neo cassette upstream of the stop codon of the Eomes (eomesodermin; also called Tbr2) gene. CreER^T2 incorporates cre recombinase fused to a G400V/M543A/L544A triple mutation of the human estrogen receptor ligand binding domain.

This construct was electroporated into (C57BL/6 x 129S4/SvJae)F1-derived v6.5 embryonic stem (ES) cells. The neomycin cassette was excised through crosses with Actin-FLPe (Stock No. 005703). The resultant Tbr2-2A-CreER allele was maintained on a mixed C57BL/6 and 129 genetic background by the donating laboratory. 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: Eomes^{tm1.1(cre/ERT2)Zjh}
Name: targeted mutation 1.1, Z Josh Huang
MGI accession ID: MGI:6720841
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible
Synonyms: Tbr2-2A-CreER; Tbr2-CreER
Marker symbol: Eomes
Marker name: eomesodermin
Marker synonyms: TBR2
Chromosome: 9
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Molecular note: The allele was generated by inserting a 2A-CreER expression cassette in-frame before the STOP codon of the Eomes gene. The targeting vectors generated using BAC clones from the RPCI-23&24 library were electroporated into a 129SVj/B6 hybrid ES cell line (v6.5). The Resulting ES cell clones were used for tetraploid complementation to obtain male heterozygous mice. The neo selection cassette was excised by crossing to FlpE strain mice.