STOCK Cort^tm1(cre)Zjh/J

Stock number: 010910
Research areas: Neurobiology Research, Research Tools

Description

Cst-T2A-Cre (Cort-T2A-Cre) mice have Cre recombinase expression directed to Cort-expressing cells (CST positive neurons) by the endogenous promoter/enhancer elements of the cortistatin locus.

Detailed description

The Cst-T2A-Cre allele (also called Cort-T2A-Cre or Cst-2A-Cre) harbors a a T2A oligopeptide that mediates ribosomal skipping (foot-and-mouth disease virus 2A from the insect Thosea asigna virus) and Cre recombinase in the 3' UTR of the cortistatin locus (Cort). As such, cre expression is directed by the endogenous Cort promoter/enhancer elements. When Cst-T2A-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Cort-expressing cells (CST positive neurons) of the offspring. Cort expression from the Cst-T2A-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 Cort expression pattern with highly efficient recombination). They report Cre recombinase activity is observed in some GABAergic interneurons, and did not examine cre expression in the intestine or tissues other than brain. Cort expression from the Cst-T2A-Cre allele was not evaluated. They also reported that homozygous mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities.

For characterization information, see images at the Allen Institute for Brain Science website (Cort-T2A-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 (Cort^tm1(cre)Zjh). This same information would also be found searching the MGI Recombinase Activity database.

Development

A targeting vector was designed to insert a T2A oligopeptide that mediates ribosomal skipping (foot-and-mouth disease virus 2A from the insect Thosea asigna virus), 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 cortistatin locus (Cort). 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 Cst-T2A-Cre mice (also called Cort-T2A-Cre or Cst-2A-Cre) were subsequently bred together for several generations (and the FLPe transgene was removed) prior to arrival at The Jackson Laboratory. Upon arrival, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Cort^tm1(cre)Zjh
Name: targeted mutation 1, Z Josh Huang
MGI accession ID: MGI:4431363
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Cort
Marker name: cortistatin
Chromosome: 4
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: When Cst-T2A-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Cort-expressing cells (CST positive neurons) of the offspring.
Molecular note: A targeting vector was designed to insert a T2A oligopeptide that mediates ribosomal skipping (foot-and-mouth disease virus 2A from the insect Thosea asigna virus), 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 cortistatin locus (Cort). 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) to generate the colony and remove the neo selection cassette. The FLPe transgene has been bred out of the line.