B6(Cg)-Cpt1a^{tm1c(EUCOMM)Hmgu}/RjnsJ

Stock number: 032778
Product name: Cpt1a^lox

Description

Cpt1a floxed mice have exon 4 of the carnitine palmitoyltransferase 1a, liver gene floxed, making these mice useful for studying long chain fatty acid oxidation.

Detailed description

Cpt1a floxed mice have loxP sites flanking exon 4 of the carnitine palmitoyltransferase 1a, liver (Cpt1a) gene. CPT1A is present in the outer mitochondrial membrane where it is considered the rate-controlling enzyme for long-chain fatty acid β-oxidation (LC-FAO). Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 4 deleted in the cre-expressing tissues. T cells with deletion of Cpt1a display reduced rates of LC-FAO.

Development

The L1L2_Bact_P cassette was inserted at a position on chromosome 19 upstream of exon 4 of the carnitine palmitoyltransferase 1a, liver (Cpt1a) gene. The cassette is composed of an FRT site followed by a lacZ sequence and a loxP site. This first loxP site is followed by neomycin under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site was inserted downstream of exon 4. The construct, clone HEPD0727_3_E10, was introduced into C57BL/6N-A^tm1Brd-derived JM8A3.N1 embryonic stem (ES) cells, and correctly targeted ES cells were injected into blastocysts. The resulting chimeric males were bred to C57BL/6NCrl mice. Subsequently these mice were bred to FLP mice to remove the FRT-flanked lacZ sequence and neomycin cassette. Resulting Cpt1a floxed offspring were bred to C57BL/6NCrl mice for at least 10 generations by the donating lab (see SNP note below). Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6NJ oocytes (Stock No. 005304).

In 2019 a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 43 markers throughout the genome suggested a C57BL/6 genetic background, all 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/6N;C57BL/6J genetic background.

Allele

Symbol: Cpt1a^{tm1c(EUCOMM)Hmgu}
Name: targeted mutation 1c, Helmholtz Zentrum Muenchen GmbH
MGI accession ID: MGI:6268444
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Synonyms: CPT1A^loxP
Marker symbol: Cpt1a
Marker name: carnitine palmitoyltransferase 1a, liver
Marker synonyms: CPT1; CPT1-L; CPTI; CPT-Ia; L-CPT I; L-CPT1
Chromosome: 19
Strain of origin: C57BL/6N-A^tm1Brd
Molecular note: The L1L2_Bact_P cassette was inserted at position 3355947 of Chromosome 19 upstream of the critical exon(s) (Build GRCm38). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site is followed by a neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site is inserted downstream of the targeted exon(s) at position 3356754. The critical exon(s) is/are thus flanked by loxP sites.A "conditional ready" (floxed) allele was created by flp recombinase expression in mice carrying this allele to remove the lacZ sequence and neo selection cassette, leaving loxP sites flanking the critical exon(s). Further information on targeting strategies used for this and other IKMC alleles can be found at http://www.informatics.jax.org/mgihome/nomen/IKMC_schematics.shtml