B6;129-Bmi1^{tm1(cre/ERT)Mrc}/J

Stock number: 010531
Product name: Bmi1^Cre-ER
Research areas: Research Tools

Description

These targeted mutant mice carry tamoxifen-inducible Cre under the transcriptional control of the mouse Bmi1 (Bmi1 polycomb ring finger oncogene) promoter. When crossed with a strain containing a loxP-flanked sequence of interest, the offspring are useful for generating tamoxifen-induced, Cre-mediated targeted deletions, and when crossed with a floxed reporter strain, lineage tracing of Bmi1-expressing cells is possible.

Detailed description

These targeted mutant mice carry tamoxifen-inducible Cre under the transcriptional control of the mouse Bmi1 (Bmi1 polycomb ring finger oncogene) promoter specifically expressed in discrete cells located near the bottom of crypts in the small intestine (predominantly four cells above the base of the crypt). When crossed with a strain containing a loxP-flanked sequence of interest, the offspring are useful for generating tamoxifen-induced, Cre-mediated targeted deletions. When crossed with a floxed reporter strain, lineage tracing of Bmi1-expressing cells is possible.

Development

An IRES (internal ribosome entry site)-Cre-ER (estrogen receptor binding domain) fusion and FRT-flanked neomycin resistance cassette was inserted between the stop codon and the first putative polyadenylation site of the targeted gene. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1- Kitl⁺-derived R1 embryonic stem (ES) cells. Resultant heterozygotes were crossed with a Flpe deleter mouse to remove the FRT-flanked neomycin cassette. This strain was maintained on a mixed C57BL/6 and 129 background by the donating laboratory.

Allele

Symbol: Bmi1^{tm1(cre/ERT)Mrc}
Name: targeted mutation 1, Mario R Capecchi
MGI accession ID: MGI:3805814
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible
Marker symbol: Bmi1
Marker name: Bmi1 polycomb ring finger oncogene
Chromosome: 2
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: Bmi1 is expressed in discrete cells located near the bottom of crypts in the small intestine, predominantly four cells above the base of the crypt (+4 position).
Molecular note: An IRES followed by a cre/ERT fusion and an frt-flanked neo cassette was inserted downstream of the translation stop codon. Germ line, flp-mediated recombination was used to remove the neo cassette.