STOCK Cck^{tm1.1(cre)Zjh}/J

Stock number: 012706
Product name: CCK-ires-Cre
Research areas: Neurobiology Research, Research Tools

Description

The Cck-IRES-Cre knock-in allele has an internal ribosome entry site and Cre recombinase in the 3' UTR of the cholecystokinin locus (Cck). As such, Cre recombinase expression is directed to Cck-expressing cells (cholecystokinin positive neurons) by the endogenous promoter/enhancer elements of the cholecystokinin locus.

Detailed description

The Cck-IRES-Cre allele harbors an internal ribosome entry site and Cre recombinase in the 3' UTR of the cholecystokinin locus (Cck). As such, cre expression is directed by the endogenous Cck promoter/enhancer elements. When Cck-IRES-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Cck-expressing cells in the offspring. Cck expression from the Cck-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 Cck expression pattern with highly efficient recombination). They report Cre recombinase activity is observed in cholecystokinin positive neurons (interneurons) of the cortex. The donating investigator did not examine cre expression in tissues other than brain (October 2012). Cck expression from the Cck-IRES-Cre allele was not evaluated. They also reported that homozygous mice are viable and fertile.

For characterization information, see images at the Allen Institute for Brain Science website (Cck-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 (Cck^{tm1.1(cre)Zjh}). This same information would also be found searching the MGI Recombinase Activity database.

Development

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 cholecystokinin locus (Cck). 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 blastocysts. Chimeric males were bred with Actin-FLPe females (on a C57BL/6 congenic background (N10); see Stock No. 005703) to achieve germline transmission and to remove the neo selection cassette. The resulting pups harboring the cre targeted mutation were selected. These Cck-IRES-Cre mice were subsequently bred together for several generations (and the FLPe transgene was removed) prior to arrival at The Jackson Laboratory Repository. Upon arrival, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Cck^{tm1.1(cre)Zjh}
Name: targeted mutation 1.1, Z Josh Huang
MGI accession ID: MGI:5014096
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Cck
Marker name: cholecystokinin
Chromosome: 9
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombinase activity is observed in cholecystokinin positive neurons (interneurons) of the cortex.
Molecular note: 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 cholecystokinin locus (Cck). This construct was electroporated into C57BL/6;129 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric males were bred with Actin-FLPe females (on a C57BL/6 congenic background) to achieve germline transmission and to remove the neo selection cassette. The resulting pups harboring the cre targeted mutation were selected. These Cck-IRES-Cre mice were subsequently bred together for several generations (and the FLPe transgene was removed).