This strain expresses Cre recombinase from the endogenous Ighg1, immunoglobulin heavy constant gamma 1, locus. This strain represents an effective tool for generating tissue specific-targeted mutants that would be useful in the study of gene function in germinal center, class switched memory and plasma cells.
Klaus Rajewsky, Max Delbruck Centre for Molecular Medicine
Genetic Background | Generation |
---|---|
|
Allele Type | Gene Symbol | Gene Name |
---|---|---|
Targeted (Recombinase-expressing) | Ighg1 | immunoglobulin heavy constant gamma 1 (G1m marker) |
Homozygous mice are viable, fertile, normal in size, and do not display any gross physical or behavioral abnormalities. Cre recombinase expression is induced by transcription of the immunoglobulin gamma1 heavy chain constant region gene (Cg1) segment and is detected as early as 4 days in 25-50% of germinal center B cells following immunization with T cell dependent antigens. By 12-14 days, 75-85% of germinal center B cells exhibit Cre-mediated recombination. Cre is detected mostly in IgG1, but also in IgG2 and IgA-expressing germinal center B cells as well as a small number of IgM+ germinal center B cells precursors.
Homozygotes exhibit a reduction in IgG1+ memory B cells and in IgG1 serum antibody titers. When bred with a mouse carrying a loxP site-flanked DNA sequence, Cre-mediated recombination results in deletion of the flanked genome segment in tissues that express the Cre transgene. This mutant mouse strain may be useful to study gene function in germinal center, class switched memory and plasma cells.
A targeting vector was used to introduce an Internal Ribosome Entry Site (IRES)-Cre-frt-flanked neomycin cassette into the 3' UTR of the immunoglobulin gamma1 constant region gene, between the last membrane coding region and its' polyadenylation site. This strategy allows for the expression of a bicistronic mRNA consisting of the immunoglobulin gamma 1 constant region (Cg1) and Cre recombinase. The construct was electroporated into 129P2/OlaHsd-derived IB10 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were tested for germline transmission. Mice were crossed to a FLPe deleter (genetic background unknown) strain to remove the neomycin cassette, leaving a single frt site upstream of the 3' UTR. The donating investigator reported that the resulting mutant mice were backcrossed to C57BL/6J for 10 generations (see SNP note below). Upon arrival, mice were bred to C57BL/6J for at least 1 generation to establish the colony.
A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 4 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.
Expressed Gene | cre, cre recombinase, bacteriophage P1 |
---|---|
Site of Expression | Cre is detected mostly in IgG1, but also in IgG2 and IgA-expressing germinal center B cells as well as a small number of IgM+ germinal center B cells precursors. |
Allele Name | targeted mutation 1, University of Cologne |
---|---|
Allele Type | Targeted (Recombinase-expressing) |
Allele Synonym(s) | Cgamma1-cre; Cy1-cre; IghC gamma1-cre; Ighg1tm1(IRES-cre)Cgn |
Gene Symbol and Name | Ighg1, immunoglobulin heavy constant gamma 1 (G1m marker) |
Gene Synonym(s) | |
Expressed Gene | cre, cre recombinase, bacteriophage P1 |
Site of Expression | Cre is detected mostly in IgG1, but also in IgG2 and IgA-expressing germinal center B cells as well as a small number of IgM+ germinal center B cells precursors. |
Strain of Origin | 129P2/OlaHsd |
Chromosome | 12 |
Molecular Note | A targeting vector containing an IRES-cre was inserted into the 3' region of the Cgamma1 locus between the last membrane-coding exon and its polyadenylation sites. This targeting design allows for the expression from the locus of a bicistronic mRNA consisting of the Cgamma1 and Cre transcript. An frt-flanked neo was removed via FLP recombinase expression. |
Mutations Made By | Dr. Stefano Casola, FIRC Institute for Molecular Oncology |
While maintaining a live colony, these mice are bred as homozygotes.
When using the Cγ1-cre mouse strain in a publication, please cite the originating article(s) and include JAX stock #010611 in your Materials and Methods section.
Facility Barrier Level Descriptions
Service/Product | Description | Price |
---|---|---|
Heterozygous for Ighg1<tm1(cre)Cgn> |
Frozen Mouse Embryo | B6.129P2(Cg)-Ighg1<tm1(cre)Cgn>/J Frozen Embryo | $2595.00 |
Frozen Mouse Embryo | B6.129P2(Cg)-Ighg1<tm1(cre)Cgn>/J Frozen Embryo | $2595.00 |
Frozen Mouse Embryo | B6.129P2(Cg)-Ighg1<tm1(cre)Cgn>/J Frozen Embryo | $3373.50 |
Frozen Mouse Embryo | B6.129P2(Cg)-Ighg1<tm1(cre)Cgn>/J Frozen Embryo | $3373.50 |
Terms are granted by individual review and stated on the customer invoice(s) and account statement. These transactions are payable in U.S. currency within the granted terms. Payment for services, products, shipping containers, and shipping costs that are rendered are expected within the payment terms indicated on the invoice or stated by contract. Invoices and account balances in arrears of stated terms may result in The Jackson Laboratory pursuing collection activities including but not limited to outside agencies and court filings.
The Jackson Laboratory has rigorous genetic quality control and mutant gene genotyping programs to ensure the genetic background of JAX® Mice strains as well as the genotypes of strains with identified molecular mutations. JAX® Mice strains are only made available to researchers after meeting our standards. However, the phenotype of each strain may not be fully characterized and/or captured in the strain data sheets. Therefore, we cannot guarantee a strain's phenotype will meet all expectations. To ensure that JAX® Mice will meet the needs of individual research projects or when requesting a strain that is new to your research, we suggest ordering and performing tests on a small number of mice to determine suitability for your particular project. We do not guarantee breeding performance and therefore suggest that investigators order more than one breeding pair to avoid delays in their research.
What information were you hoping to find through your search?
How easy was it to find what you were looking for?
We may wish to follow up with you. Enter your email if you are happy for us to connect and reachout to you with more questions.
Please Enter a Valid Email Address
Thank you for sharing your feedback! We are working on improving the JAX Mice search. Come back soon for exciting changes.