The SIRT3 knock-out allele abolishes sirtuin 3 expression. These mice may be useful in studying the role of fatty acid oxidation in diabetes, cardiovascular disease, steatosis, fasting, cold exposure and life span.
Dr. Frederick W. Alt, Children's Hospital
The targeted mutation deletes exon 2-3 of the mouse sirtuin 3 gene (Sirt3), abolishing gene function. Homozygous mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Sirt3-/- mice exhibit hyperacetylation of mitochondrial enzymes, including glutamate dehydrogenase (GDH) and long-chain acyl co-enzyme A dehydrogenase (LCAD), leading to a decrease in the modulation of mitochondrial metabolism and fatty acid oxidation. They show reduced ATP production, cold intolerance, and hypoglycemia. These mice may be useful in studying the role of fatty acid oxidation in diabetes, cardiovascular disease, steatosis, fasting, cold exposure and life span.
A targeting vector was designed to replace exon 2-3 of the mouse sirtuin 3 gene (Sirt3) with a neomycin-resistance cassette. Specifically, a loxP site was inserted upstream of exon 2, and a floxed neo cassette was inserted downstream of exon 3. This construct was electroporated into 129S6/SvEvTac-derived TC1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts and the resulting chimeric males were bred to 129/Sv females. Mice heterozygous for the Sirt3 mutant allele were crossed to EIIa-cre mice on a 129 background to remove the floxed exons and the neo cassette. These mice were then intercrossed to produce homozygous Sirt3-/- mice. Upon arrival at The Jackson Laboratory, mice were bred to 129S1/SvImJ inbred mice (Stock No. 002448) for at least one generation to establish the colony.
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. One of the 43 markers, on Chomosome 6, was segregating with B6.
|Allele Name||targeted mutation 1.1, Frederick W Alt|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Sirt3, sirtuin 3|
|Strain of Origin||129S6/SvEvTac|
|Molecular Note||A floxed neo cassette was inserted into intron 3 and an additional loxP site was inserted upstream of exon 2. Cre-mediated recombination was used to remove the neo cassette, exon 2 and exon 3. The absence of protein product was confirmed by western blot analysis on liver and brain extracts.|
|Mutations Made By|| |
Dr. Frederick Alt, Children's Hospital
When maintaining a live colony, homozygous mice may be bred together.
When using the Sirt3- mouse strain in a publication, please cite the originating article(s) and include JAX stock #012755 in your Materials and Methods section.