B6.Cg-Vps35^tm1.1Mjff/J

Stock number: 023409
Product name: VPS35 D620N

Research areas: Neurobiology Research

Description

These mutant mice express the D620N mutation in exon 15 of the Vps35 (VPS35 retromer complex component) gene. VPS35 D620N KI mice recapitulate many of the characteristics of Parkinson's disease including neurodegeneration of DA neurons, accumulation of α-synuclein in DA neurons and age-dependent progressive motor deficits.

Detailed description

Vps35 (VPS35 retromer complex component) encodes a component of the heteropentameric retromer complex, which mediates retrograde transport of cargo proteins from endosomes to the trans-Golgi network, endosome to plasma membrane and mitochondria to peroxisomes or lysome. Vsp35 is highly expressed in dopaminergic neurons. The D620N mutation is associated with late-onset autosomal dominant Parkinson's disease (PD). The mutation alters cargo recognition of substrates and causes alterations in trafficking.

VPS35 D620N knock-in (KI) mice are viable and fertile. Young mice (6-10 months) exhibit no obvious phenotype. However, by 14 months of age homozygotes develop age-dependent progressive motor deficits (reduced travel distance, reduced speed in beam walking), reduced levels of dopamine in the striatum, loss of dopaminergic neurons in the substantia nigra and striatum, increased neuroinflammation, and accumulation and aggregation of α-synuclein in dopaminergic neurons, mitochondrial fragmentation, and increased susceptibility of dopaminergic neurons to environmental toxins. (Niu M et al, Aging Cell 2021, PMID 33745227). These mice may be useful in studies of Parkinson's disease.

Please note: A strain with inducible expression of D620N is also available, Stock No. 021807 B6.Cg-Vps35^tm1.2Mjff/J.

Development

A targeted vector containing a floxed "mini-cDNA" (splice acceptor, sequence encoding exons 15 through 17, polyadenylation signal), with a FRT site flanked NEO cassette on the 3' end of the mini-cDNA and a third loxP site, was inserted into intron 14-15. The construct was electroporated into C57BL/6 derived Bruce4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were tested for germline transmission. The mice were then crossed to FLP expressing mice on the C57BL/6J genetic background, to remove the NEO cassette. The FLP recombinase transgene was then bred out from the line. Sequencing confirmed the presence of the point mutation. The mice were maintained on the C57BL/6 background. Upon arrival at The Jackson Laboratory, the mice (Stock No. 021807) were crossed to C57BL/6J (Stock No. 000664) at least once. The Stock No. 021807 mice were then crossed to Cre deleter line on the B6 background (Stock No. 008454) to remove the floxed "mini-cDNA" sequence and allow expression of the D620N mutation. The mice were then bred to remove the Cre recombinase allele.

Allele

Symbol: Vps35^tm1.1Mjff
Name: targeted mutation 1.1,The Michael J Fox Foundation
MGI accession ID: MGI:5607779
Generation method: Targeted
Attributes: Humanized sequence
Marker symbol: Vps35
Marker name: VPS35 retromer complex component
Chromosome: 8
Strain of origin: B6.Cg-Thy1^a
Molecular note: A targeted vector containing a floxed "mini-cDNA" including a splice acceptor and normal cDNA sequence for exons 15-17, followed by a frt-flanked neo cassette and a third loxP site, inserted into intron 14, and a nucleotide change causing a D620N mutation in the inherent mouse gene sequence 3' of the insertion. The polyadenylation signal sequence at the end of the mini-cDNA prevents expression of the D620N mutation. Flp-mediated recombination removed the neo cassette. Cre-mediated recombination removed the "mini-cDNA" sequence and allows expression of the D620N mutation.