STOCK En2^tm5.1Alj/J

Stock number: 007925
Research areas: Neurobiology Research, Research Tools

Description

These En2^flox-taulacZ (En2-floxLacZ, En2^tau-lacZ, or En2-tau-lacZ) mutant mice harbor a loxP-flanked tau β-galactosidase "knock-in" allele that also abolishes engrailed 2 (En2) gene function, and may be useful for conditional reporter protein expression in En2-expressing tissues (including the early mesencephalon and rhombomere 1, and developing cerebellum and jaw muscles), as well as for conditional restoration of En2 function.

Detailed description

Mice homozygous for this En2^flox-taulacZ (also called En2-floxLacZ, En2^tau-lacZ, or En2-tau-lacZ) mutation are viable but may not breed well (reported as "semi-fertile"). These mice harbor a loxP-flanked tau β-galactosidase "knock-in" allele that also abolishes engrailed 2 (En2) gene function. While both the tau-lacZ and En2 transcripts are made, only tau-lacZ is translated to protein. Expression of lacZ mimics that of the endogenous En2 gene. When bred to mice that express Cre recombinase, the resulting offspring will have the lacZ reporter deleted in the cre-expressing tissue(s) with subsequent restoration of En2 translation. These En2^flox-taulacZ mutant mice may be useful for conditional reporter protein expression in En2-expressing tissues (including the early mesencephalon and rhombomere 1, and developing cerebellum and jaw muscles), as well as for conditional restoration of En2 function.

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. 007918, and Stock No. 007924).

Development

A targeting vector was designed to insert a loxP-flanked tau-lacZ cassette followed by a neo cassette and then a third loxP site into the 5'-UTR 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 Webster mice. The resulting offspring were then bred to cre expressing mice (on a Swiss Webster genetic background) to remove the neo cassette, generating En2^flox-taulacZ offspring (also called En2-floxLacZ in Sgaier 2005 or En2^tau-lacZ and En2-tau-lacZ in Sgaier 2007). These En2^flox-taulacZ mutant mice were bred 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, En2^flox-taulacZ mice were bred to 129S1/SvImJ (Stock No. 002448) for at least one generation to establish the colony.

Allele

Symbol: En2^tm5.1Alj
Name: targeted mutation 5.1, Alexandra L Joyner
MGI accession ID: MGI:3789089
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: En2
Marker name: engrailed 2
Chromosome: 5
Strain of origin: 129S6/SvEvTac
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: LoxP-flanked tau ?-galactosidase expression mimics and blocks that of the endogenous targeted gene. When bred to Cre recombinase mice, resulting offspring will have the lacZ reporter deleted in the cre-expressing tissue(s) with subsequent restoration of the targeted gene's translation.
Molecular note: A targeting vector was designed to insert a loxP-flanked tau-lacZ cassette followed by a neo cassette and then a third loxP site into the 5'-UTR of the targeted gene. Cre mediated recombination then removed the neo cassette leaving the floxed tau-lacZ cassette intact.