B6.129S6(Cg)-Sirt3^tm1.1Fwa/J

Stock number: 027975
Product name: SIRT3 knock-out
Research areas: Diabetes and Obesity Research, Metabolism Research, Research Tools

Description

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.

Detailed description

The targeted mutation deletes exons 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.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. This is the case for the strain above. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

Development

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, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664). The mice were then backcrossed to C57BL/6J (Stock No. 000664) using a marker assisted protocol.

Allele

Symbol: Sirt3^tm1.1Fwa
Name: targeted mutation 1.1, Frederick W Alt
MGI accession ID: MGI:3769234
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Sirt3^-
Marker symbol: Sirt3
Marker name: sirtuin 3
Marker synonyms: 2310003L23Rik; SIR2L3
Chromosome: 7
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.