STOCK En1^tm8.1Alj/J

Stock number: 007918
Research areas: Neurobiology Research, Research Tools

Description

These En1^flox mice harbor loxP-flanked homeodomain portion of exon 2 of the engrailed 1 (En1 locus. When bred to mice that express Cre recombinase, the resulting offspring will have this region deleted in the cre-expressing tissue(s). As such, these mice may be useful in generating conditional mutations for studying engrailed protein function in the embryonic mesencephalon and rhombomere 1, as well as developing cerebellum, limbs, somites, and skin.

Detailed description

Mice homozygous for the En1^flox conditional allele are viable and fertile, with loxP sites flanking the coding region of exon 2 of the targeted gene. When bred to mice that express Cre recombinase, the resulting offspring will have this region (encoding the engrailed homeodomain) deleted in the cre-expressing tissue(s). These En1^flox mice may be useful in generating conditional mutations for studying engrailed protein function in the embryonic mesencephalon and rhombomere 1, as well as developing cerebellum, limbs, somites, and skin.

Of note, these mice may also be useful in conjunction with other engrailed mutants (such as Stock No. 007912, Stock No. 007916, Stock No. 007917, Stock No. 007924, and Stock No. 007925).

Development

A targeting construct was designed to insert an frt-flanked neomycin cassette and loxP site upstream, and a loxP site downstream of the second exon of the targeted gene. This construct was electroporated into 129S6/SvEvTac-derived W4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts and chimeric mice were bred with Black Swiss mice (to avoid rescue of the En1 mutant phenotype by the C57BL/6 background). The resulting En1^flox-neo mice were then bred to 129 mice constitutively expressing Flp recombinase (see Stock No. 003800) to remove the Frt-flanked neo cassette, generating En1^flox offspring. These En1^flox mutant mice were bred together or to Swiss Webster mice for many generations prior to arrival at The Jackson Laboratory. In addition, the donating investigator reports that although these mice harbor no additional mutant loci, they may contain incidental genetic background contributions as a result of past matings with other mutant mouse strains. Upon arrival, En1^flox mice were bred to 129S1/SvImJ (Stock No. 002448) for at least one generation to establish the colony.

Allele

Symbol: En1^tm8.1Alj
Name: targeted mutation 8.1, Alexandra L Joyner
MGI accession ID: MGI:3789091
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: En1
Marker name: engrailed 1
Chromosome: 1
Strain of origin: 129S6/SvEvTac
Molecular note: A targeting construct was designed to insert an frt-flanked neomycin cassette and loxP site upstream, and a loxP site downstream of the second exon of the targeted gene. Correctly targeted ES cells were injected into recipient blastocysts and chimeric mice were bred with Black Swiss mice (to avoid rescue of the En1 mutant phenotype by the C57BL/6 background). The resulting En1flox-neo mice were then bred to 129 mice constitutively expressing Flp recombinase to remove the Frt-flanked neo cassette, generating En1flox offspring.