STOCK Gad2^tm2(cre)Zjh/J

Stock number: 010802
Product name: Gad2-IRES-Cre
Research areas: Neurobiology Research, Research Tools

Description

Gad2-IRES-Cre knock-in mice have Cre recombinase expression directed to GAD2 positive neurons. These mice may be used to generate conditional mutations for studying GAD2 cell populations.
Of note, the same Gad2-IRES-Cre knock-in allele is also available as C57BL/6N-congenic (Stock No. 019022) and C57BL/6J-congenic (Stock No. 028867).

Detailed description

The Gad2-IRES-Cre knock-in allele has an internal ribosome entry site and Cre recombinase in the 3' UTR of the glutamic acid decarboxylase 2 locus (Gad2). As such, the endogenous Gad2 promoter/enhancer elements direct cre expression to GAD2 positive neurons. When Gad2-IRES-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Gad2-expressing cells (GAD2 positive neurons) of the offspring. Gad2 expression from the Gad2-IRES-Cre allele has not been evaluated. Additional phenotype information described below.

In 2010, the donating investigator reported Cre recombinase activity is specific and efficient (largely recapitulates the endogenous Gad2 expression pattern with highly efficient recombination). The donating investigator did not examine cre expression in tissues other than brain. Gad2 expression from the Gad2-IRES-Cre allele was not evaluated. They also report that homozygous mice are viable and fertile.

For characterization information of the Gad2-IRES-Cre knock-in allele, see images at the Allen Institute for Brain Science website (Gad2-IRES-Cre images).

If the recombinase activity pattern of this allele is further characterized by the Genetic Resource Science group at The Jackson Laboratory, such findings will be reported on the Mouse Genome Informatics (MGI) Allele Detail entry (Gad2^tm2(cre)Zjh). This same information would also be found searching the MGI Recombinase Activity database.

Development

The Gad2-IRES-Cre knock-in allele was designed by Dr. Z. Josh Huang (Cold Spring Harbor Laboratory). A targeting vector was designed to insert an internal ribosome entry site (IRES), a Cre recombinase sequence, a polyA sequence, and an frt-flanked neo cassette into the 3' untranslated region (after the translational termination site) of the glutamic acid decarboxylase 2 locus (Gad2) on chromosome 2. This construct was electroporated into (C57BL/6 x 129S4Sv/Jae)-derived V6.5 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient tetraploid blastocysts. Chimeric mice were bred with Actin-FLPe mice (on a C57BL/6 congenic background (N10); see Stock No. 005703) to generate the colony and remove the neo selection cassette. These Gad2-IRES-Cre mice were subsequently bred together for many generations (and the FLPe transgene was removed). In 2010, Gad2-IRES-Cre knock-in mice on a mixed genetic background (mostly C57BL/6;129S4 ; with black coat color) were sent to The Jackson Laboratory Repository. Upon arrival, sperm was cryopreserved. An aliquot of that frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664) and rederive our live colony, which was thereafter maintained by breeding mutant mice together.

Allele

Symbol: Gad2^tm2(cre)Zjh
Name: targeted mutation 2, Z Josh Huang
MGI accession ID: MGI:4418713
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Gad2
Marker name: glutamic acid decarboxylase 2
Chromosome: 2
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: When Gad2-IRES-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Gad2-expressing cells (GAD2 positive neurons) of the offspring.
Molecular note: A targeting vector was designed to insert an internal ribosome entry site (IRES), a Cre recombinase sequence, an SV40 polyA signal, and an frt-flanked neo cassette into the 3' untranslated region (after the translational termination site) of the Gad2 (glutamic acid decarboxylase 2) gene. This construct was electroporated into C57BL6/S129 hybrid embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient tetraploid blastocysts. Chimeric mice were bred with Actin-FLPe mice (on a C57BL/6 congenic background (N10)) to remove the selection cassette. The FLPe transgene was subsequently bred out of the background.