STOCK Gpd2^tm1Tka Slc25a13^tm1Lct/TsahMmjax

Stock number: 036927
Product name: Ctrn/mGPD
Strain synonyms: Ctrn/mGPD
Research areas: Diabetes and Obesity Research, Internal/Organ Research, Metabolism Research, Mouse/Human Gene Homologs

Description

Ctrn/mGPD double knockout mice carry null alleles of both the Gpd2 (glycerol phosphate dehydrogenase 2, mitochondrial or mGPDH) and Slc25a13 (solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator), member 13 or Ctrn) genes. Ctrn/mGPD mice develop citrullinemia, hyperammonemia, hypoglycemia and fatty liver and maybe used as a mouse model of human citrin deficiency.

Detailed description

Ctrn/mGPD double knockout mice carry null alleles of both the Gpd2 (glycerol phosphate dehydrogenase 2, mitochondrial or mGPDH) and Slc25a13 (solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator), member 13 or Ctrn) genes.

Gpd2 (glycerol phosphate dehydrogenase 2, mitochondrial or mGPDH) encodes a mitochondrial dehydrogenase that is a component of the glycerol phosphate shuttle and functions to reoxidize NADH formed during glycolysis. mGPDH-/- KO mice have exon 5 disrupted by a neomycin cassette, which results in a null allele.

Slc25a13 (solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator or citrin/Ctrn) encodes a member of the mitochondrial carrier family that catalyzes the exchange of mitochondrial aspartate for cytoplasmic glutamate and a proton across the inner mitochondrial membrane. Mutations in SLC25A13 are associated with age-specific clinical presentations including neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and adult-onset type II citrullinemia (CTLN2), as well neuropsychiatric symptoms.

Double knockout Ctrn/mGPD mice exhibit hyperammonemia (under fed conditions, and exacerbated by sucrose administration), citrullinemia, hypoglycemia (under fed and fasted conditions), decreased plasma insulin levels, an altered threonine/serine ratio, an increased hepatic lactate/pyruvate ratio (worsened by sucrose administration), increased liver triglyceride levels (under fasted conditions) and fatty liver (under fasted conditions). Ctrn/mGPD knockout mice are viable but with a lower body weight. Crosses of heterozygous Ctrn-/+ and homozygous mGPD-/- mice yield a 30% loss of the expected numbers of double homozygotes. This strain may be used as a mouse model of human citrin deficiency.

Please note one of the single mutants are available as B6.129-Slc25a13^tm1Lct/TsahMmjax, MMRRC Stock No. 069593.

Development

Ctrn/mGPD double knockout mice were generated by crossing the two strains B6.129-Slc25a13^tm1Lct/Tsah and B6.Cg-Gpd2^tm1Tka/Tsah and intercrossing progeny to create double homozygous knock-outs. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation. The development of each strain is described below.

mGPDH^- mice were created in the laboratory of Dr. Takashi Kadowaki (University of Tokyo). The targeting vector was designed to insert a PGK-neomycin cassette within exon 5 of the Gpd2 (glycerol phosphate dehydrogenase 2, mitochondrial) gene on chromosome 2. The construct was electroporated into (C57BL/6NCrlj x CBA/JNCrlj)F1-derived TT2 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric males were bred with C57BL/6J females. Immunoblot and the enzyme activity assay confirm the absence of protein. In 2006, mice from the colony were transferred into the laboratory of Dr. Takeyori Saheki (Kagoshima University) and were bred to C57BL/6J mice for at least 9 generations.

Ctrn^- mice were created by Dr. David S. Sinasac (University of Toronto). The targeting vector was designed to replace a 347 bp region containing exon 10 with a PGK-neomycin cassette (in the opposite orientation) in the Slc25a13 gene on chromosome 6. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric males were bred with 129S1/SvImJ females. Western blot analysis confirmed the absence of citrin protein in kidney, liver and heart. In 2006, mice from the colony were transferred into the laboratory of Dr. Takeyori Saheki (Kagoshima University) and were bred to C57BL/6J mice for at least 9 generations.

In 2022, 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 male sent to The Jackson Laboratory Repository. Three of the 43 markers throughout the genome were segregating with CBA, and one marker was segregating with CBA or 129, suggesting an incomplete backcross.

Allele

Symbol: Gpd2^tm1Tka
Name: targeted mutation 1, Takashi Kadowaki
MGI accession ID: MGI:2181289
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: mGPDH-
Marker symbol: Gpd2
Marker name: glycerol phosphate dehydrogenase 2, mitochondrial
Marker synonyms: GDH2; Gdm1; GPDM; mGDH; mGPDH; mtGPDH
Chromosome: 2
Strain of origin: (C57BL/6NCrlj x CBA/JNCrlj)F1
Molecular note: The gene was disrupted by insertion of a PGK-neo cassette into exon 5 via homologous recombination. The absence of protein expression was verified by Western blot and enzyme assay of islet samples from homozygous mutant animals.

Allele

Symbol: Slc25a13^tm1Lct
Name: targeted mutation 1, Lap-Chee Tsui
MGI accession ID: MGI:3028639
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Ctrn ^-/-
Marker symbol: Slc25a13
Marker name: solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator), member 13
Marker synonyms: ARALAR2; citrin; CTLN2; Ctrn; NICCD; RGD1565889
Chromosome: 6
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A 347 bp region containing exon 10 was replaced with a neomycin resistance gene inserted in opposite orientation. Absence of mRNA transcript was confirmed by Northern blot and absence of protein product by Western blot analysis.