B6.129X1(C)-Gba1^tm2.1Eginn/J

Stock number: 024575
Product name: Gba*R463C
Research areas: Neurobiology Research

Description

These Gba*R463C mice contain a mutation in the Gba1 gene, similar to that found in humans with Gaucher disease and Parkinson's disease.

Detailed description

These Gba*R463C mice contain the mutation R463C in intron 10 of the glucosidase, beta, acid 1 (Gba1) gene. This mutation introduces an arginine to cysteine mutation analogous to a common Gba1 mutation found in humans with the α-synucleinopathy Gaucher disease. In Gaucher disease, mutations of the lysosomal enzyme GBA1 prevents the degradation of its substrate, glucocerebroside, into ceramide and glucose, resulting in an accumulation of glucocerebroside within lysosomes mainly in macrophages. These lipid-filled mutant macrophages contribute to the enlargement of the spleen and liver, damage to blood-forming tissues, bone fractures and pain, and damage to the lungs and nervous tissues. Gaucher disease is rare, but is more prevalent among individuals of Ashkenazi Jewish descent. Carriers of GBA1 mutations often have a higher genetic risk of developing Parkinson's disease and Lewy body.

Homozygous Gba*R463C mice are viable and fertile. The R463C mutation is associated with less severe type 1 non-neuronopathic Gaucher disease characterized by later onset of major visceral and progressive CNS disease. The Gba1 enzyme activity in liver and spleen was 35% and 13% of the Gba1 enzyme activity in normal mice, respectively. Gba1 activity levels in brain were 65% of wildtype. Enhanced α-syn accumulation and astroglial activation are apparent in the nigrostriatal pathway of these mice. These are relevant for the study of Gaucher and Parkinson's disease.

Development

A targeting construct was designed to insert a loxP-flanked neomycin (neo) resistance cassette, in opposite orientation to the gene, downstream of the coding region of the glucosidase, beta, acid 1 (Gba1) gene. A point mutation was introduced in intron 10, resulting in an arginine to cysteine mutation, R463C, commonly found in humans carrying Gaucher disease. This targeting construct was electroporated into 129X1/SvJ-derived RW4 embryonic stem (ES) cells and correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric males were bred to C57BL/6NCr females, and offspring were bred to B6.C-Tg(CMV-cre)1Cgn/J mice (Stock No. 006054) to remove the floxed neo cassette. Progeny were crossed to remove the cre transgene, and resulting mice were bred to C57BL/6NCr for at least 10 generations. Upon arrival at The Jackson Laboratory Repository, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6NJ oocytes (Stock No. 005304).

Allele

Symbol: Gba1^tm2.1Eginn
Name: targeted mutation 2.1, Edward I Ginns
MGI accession ID: MGI:5587918
Generation method: Targeted
Attributes: Hypomorph
Synonyms: R463C
Marker symbol: Gba1
Marker name: glucosylceramidase beta 1
Marker synonyms: betaGC; GBA; GBA1; GC; GCase; GCB; GLUC; glucocerebrosidase
Chromosome: 3
Strain of origin: 129X1/SvJ
Molecular note: A point mutation resulted in R463C substitution was introduced by PCR mutagenesis. Cre mediated recombination removed loxP-flanked neomycin cassette between metaxin and glucocerebrosidase, leaving only a 34 bp loxP sequence. Gba activity decreased to approximately 35% of the enzyme activity in normal mice.