STOCK Trpa1^tm2Kykw Tg(CAG-cre/Esr1*)5Amc/J

Stock number: 008813
Product name: Trpa1^CKO;pCAGGCre-ER^TM
Strain synonyms: Trpa1 CKO/CKO deltaNeo Tg(cre/Esr1)5Amc/J
Research areas: Cancer Research, Neurobiology Research, Research Tools

Description

This Trpa1^CKO;pCAGGCre-ER^TM compound mutant has a floxed allele of the Trpa1 (transient receptor potential cation channel, subfamily A, member 1) gene in addition to a tamoxifen inducible cre transgene driven by the chicken beta actin promoter/enhancer coupled with the cytomegalovirus (CMV) immediate-early enhancer (see Stock No. 004682). Restricted to the cytoplasm, the cre/Esr1 protein can only gain access to the nuclear compartment after exposure to tamoxifen. Tamoxifen administration induces cre recombination within the Trpa1 allele, excising the S5/S6 transmembrane domains. Animals not treated with tamoxifen display no observable phenotype.

Detailed description

This Trpa1^CKO;pCAGGCre-ER^TM compound mutant has a floxed allele of the Trpa1 (transient receptor potential cation channel, subfamily A, member 1) gene in addition to a tamoxifen inducible Cre transgene driven by the chicken beta actin promoter/enhancer coupled with the cytomegalovirus (CMV) immediate-early enhancer (see Stock No. 004682). Restricted to the cytoplasm, the cre/Esr1 protein can only gain access to the nuclear compartment after exposure to tamoxifen. Tamoxifen administration induces cre recombination within the Trpa1 allele, excising the S5/S6 transmembrane domains. Animals not treated with tamoxifen display no observable phenotype.

Development

This Trpa1^CKO;pCAGGCre-ER^TM compound mutant strain was created by intercrossing the Trpa1 floxed strain with the tamoxifen-inducible pCAGGCre-ER^TM transgenic strain as described below.

To create the Trpa1 floxed allele (Trpa1^CKO), loxP sites were placed on either side of the exons that encode the S5/S6 transmembrane domains. An FRT-flanked self-excising neomycin resistance cassette was initially placed within the floxed allele, and was deleted. The mutation was created with 129S6/SvEvTac-derived TC1 embryonic stem (ES) cells.

The pCAGGCre-ER^TM transgene was designed by Drs. Shigemi Hayashi and Andrew P. McMahon (while at Harvard University) to have the CMV-IE enhancer/chicken β-actin/rabbit β-globin hybrid promoter (CAG; originally from the pCAGGS vector) and CreERTM fusion gene (CreER^TM; Cre recombinase fused to a G525R mutant form of the mouse estrogen receptor ligand binding domain) - as described for Stock No. 004682.

This compound mutant strain is on a mixed genetic background that involves C57BL/6, CBA, and 129.

In 2022, the Tg(CAG-cre/Esr1*)5Amc transgene creator's laboratory provided the cDNA sequence of the Cre‐ERTM portion - available here. Currently, this transgene is present in the following available Stock Nos. 004682, 004453, 008783, 008813, 017595, 019102, 034795, 034859.

Allele

Symbol: Tg(CAG-cre/Esr1*)5Amc
Name: transgene insertion 5, Andrew P McMahon
MGI accession ID: MGI:2182767
Generation method: Transgenic
Attributes: Recombinase-expressing; Inducible
Marker symbol: Tg(CAG-cre/Esr1*)5Amc
Marker name: transgene insertion 5, Andrew P McMahon
Chromosome: UN
Strain of origin: (C57BL/6 x CBA)F1
Expressed genes: cre/Esr1,Cre recombinase and estrogen receptor 1 fusion gene,
Site of expression: tamoxifen-inducible cre; widespread pattern of expression; tamoxifen administration will also induce Cre recombination in developing embryos of treated mothers and in cultured cells derived from transgenic mice
Molecular note: This transgene expresses a fusion protein consisting of Cre recombinase joined to the ligand-binding domain of a mouse estrogen receptor modified to bind to 4-hydroxytamoxifen, but not to endogenous estrogen. The CAG promoter, containing a chicken beta actin promoter/enhancer coupled with the cytomegalovirus immediate-early (CMV-IE) enhancer, drives high levels of expression in most tissues. In the presence of tamoxifen, the fusion protein is transported into the nucleus, where cre can excise loxP-flanked segments from conditionally modified genes.
General note: Homozygous transgenic mice are not viable or fertile. Hemizygous transgenic mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities.

In transgenic mice the mutant mouse estrogen receptor does not bind natural ligand at physiological concentrations but will bind the synthetic ligand, 4-hydroxytamoxifen. Restricted to the cytoplasm, the Cre/Esr1 fusion protein can only gain access to the nuclear compartment after exposure to tamoxifen. When crossed with a strain containing loxP sites flanking a sequence of interest, tamoxifen induced, Cre-mediated targeted deletions are generated in the offspring. Tamoxifen administration will induce Cre recombination in developing embryos of treated mothers and in cultured cells derived from transgenic mice.

Note that this transgene does not contain the cre/ERT2 fusion but was mistakenly referred to by the synonym CAG-CreERT2 in publication. J:136965

Note that this transgene does not contain the cre/ERT2 fusion but was mistakenly referred to by the synonym CAGG-CreERT2 in publication. J:130851

Allele

Symbol: Trpa1^tm2Kykw
Name: targeted mutation 2, Kelvin Y Kwan
MGI accession ID: MGI:3814427
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Trpa1
Marker name: transient receptor potential cation channel, subfamily A, member 1
Chromosome: 1
Strain of origin: 129S6/SvEvTac
Molecular note: LoxP sites were placed on either side of exons 22-24 (encoding the S5/S6 transmembrane domains) and an FRT-flanked neomycin resistance cassette inserted in the opposite transcriptional orientation in intron 24. The neomycin cassette was excised by crossing these mice to a Gt(ROSA)26Sor-driven Flp strain on a 129S4/SvJaeSor.