B6N.Cg-Cck^{tm1.1(cre)Zjh}/J

Stock number: 019021
Product name: Cck-IRES-Cre
Research areas: Neurobiology Research, Research Tools

Description

The Cck-IRES-Cre knockin 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.

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.

The parental line, Cck-IRES-Cre knockin mice on a C57BL/6;129 genetic background, are available and described as Stock No. 012706. It should be noted that the phenotype of these C57BL/6NJ-congenic Cck-IRES-Cre knockin mice (Stock No. 019021) could vary from that of the parental line from which it was derived. We may modify the C57BL/6NJ-congenic strain description if necessary as published results become available.

Development

Mice harboring the Cck-IRES-Cre knockin allele on a C57BL/6;129 genetic background were sent to The Jackson Laboratory Repository in 2010 (as Stock No. 012706). Upon arrival, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at one generation, and then bred together to maintain the colony. In 2012, some mice were bred to C57BL/6NJ inbred mice (Stock No. 005304) for many generations using a marker-assisted, speed congenic approach to generate this C57BL/6NJ-congenic strain (Stock No. 019021). This approach employed 148 single nucleotide polymorphism (SNP) markers that differ between the C57BL/6N and C57BL/6J substrains, covering all 19 chromosomes and the X chromosome. This analysis has determined that all SNP markers are now C57BL/6N allele-type (with the exception of 1 markers near the Cck locus on chromosome 9).

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
Synonyms: Cck-IRES-Cre
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).