When these Mc3r-/- floxed-STOP mice are bred to mice that express Cre recombinase, resulting bi-allelic offspring will have a floxed-STOP sequence deleted in cre-expressing tissues, allowing Mc3r expression. These mice may be useful when studying metabolism and obesity.
Andrew A. Butler, The Scripps Research Institute
Genetic Background | Generation |
---|---|
|
Allele Type | Gene Symbol | Gene Name |
---|---|---|
Targeted (Conditional ready (e.g. floxed), No functional change) | Mc3r | melanocortin 3 receptor |
These Mc3r-/- mutant mice possess a floxed STOP-neo cassette upstream of the start codon, and an IRES-GFP cassette downstream of the stop codon of the melanocortin 3 receptor (Mc3r) gene. MC3R is a G-protein coupled receptor for the melanocyte-stimulating hormone. It is expressed in the hypothalamic and limbic regions of the brain and in some peripheral tissues including the renal cortex and medulla, and the immune system. MC3R contributes to the regulation of body composition, salt excretion, immune function, and energy homeostasis. Homozygous MC3R-/- males are fertile while homozygous females are poor breeders. These floxed-STOP mice exhibit increased susceptibility to diet-induced obesity, with increased fat mass and decreased lean mass when fed a standard chow diet. These mice can also exhibit increased circulating insulin and leptin levels, changes in serum triglyceride levels, changes in the respiratory exchange ratio (indicating altered whole body substrate preference), and decreased physical activity.
When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have the STOP cassette deleted, allowing MC3R expression in cre-expressing tissues.
For example, when bred to B6.Cg-Tg(Nes-cre)1Kln/J (Stock No. 003771) expressing Cre in the nervous system, the resulting offspring display a partial rescue of the obesity phenotype.
When bred to FVB-Tg(Nr5a1-cre)2Lowl/J (Stock No. 006364) expressing Cre in steroidogenic factor-1 (SF1)-positive neurons, the resulting offspring exhibit improvements in metabolic homeostasis.
The donating investigator reports that although an
IRES-GFP is present in the allele, expression is too low to detect.
A targeting vector was designed to insert a floxed STOP-neo cassette was placed upstream of the translational start site of the melanocortin 3 receptor (Mc3r) gene. An Internal ribosome entry site (IRES) fused to an enhanced green fluorescent protein (AcGFP1) was placed downstream of open reading frame. The construct was electroporated into C57BL/6-derived Bruce-4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into B6(Cg)-Tyrc-2J/J blastocysts and resulting chimeric males were bred to B6(Cg)-Tyrc-2J/J females. The donating investigator stated that these mice were backcrossed to C57BL/6J (see SNP note below). Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one 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, 3 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 C57BL/6N genetic background.
Allele Name | targeted mutation 1, Andrew A Butler |
---|---|
Allele Type | Targeted (Conditional ready (e.g. floxed), No functional change) |
Allele Synonym(s) | Mc3rTB |
Gene Symbol and Name | Mc3r, melanocortin 3 receptor |
Gene Synonym(s) | |
Strain of Origin | B6.Cg-Thy1a |
Chromosome | 2 |
Molecular Note | A loxP-stop-loxP cassette was inserted just upstream of the initiation codon and an IRES-AcGFP1was inserted after the open reading frame via homologous recombination. |
Mutations Made By | Andrew Butler, The Scripps Research Institute |
When maintaining a live colony, heterozygous females may be bred to homozygous males. The donating investigator reports that homozygous females are poor breeders.
When using the B6(Cg)-Mc3rtm1Butl/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #017866 in your Materials and Methods section.
Facility Barrier Level Descriptions
Service/Product | Description | Price |
---|---|---|
Heterozygous for Mc3r<tm1Butl> |
Frozen Mouse Embryo | B6(Cg)-Mc3r<tm1Butl>/J | $2595.00 |
Frozen Mouse Embryo | B6(Cg)-Mc3r<tm1Butl>/J | $2595.00 |
Frozen Mouse Embryo | B6(Cg)-Mc3r<tm1Butl>/J | $3373.50 |
Frozen Mouse Embryo | B6(Cg)-Mc3r<tm1Butl>/J | $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.