STOCK Snca^tm1Rosl Tg(Cnp-SNCA)M2Vle/KlukJ

Stock number: 037870
Product name: KOM2
Research areas: Neurobiology Research

Description

KOM2 mice harbor an α-Syn knock-out (KO) allele and a full-length human α-synuclein transgene driven by the endogenous Cnp promoter (CNP-α-Syn M2 line). These mice may be useful for studying the pathogenic overexpression of α-synuclein in oligodendrocytes, reminiscent of multiple system atrophy disease (MSA).

Detailed description

α-Synuclein is a neuronal protein (coded by Snca) which plays a role in synaptic plasticity and neurotransmitter release. Mutations of Snca have been implicated in a group of neurodegenerative diseases that result from an accumulation of α-synuclein in neurons or, in some cases, glial cells. These disorders include Parkinson's disease, dementia with Lewy bodies, the Lewy body variant of Alzheimer's disease (AD), multiple system atrophy, and neurodegeneration with brain iron accumulation. KOM2 mice carry an α-Syn knock-out (KO) allele (Stock No. 003692) and a full-length human α-synuclein transgene (CNP-α-Syn M2 line). The CNP-α-Syn transgene is driven by the mouse 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter (Cnp) resulting in expression in oligodendrocytes exclusively.

Mice that are homozygous for the α-Syn targeted mutation and homozygous for CNP-α-Syn transgene (KOM2) are viable and fertile. While the donating investigator has not evaluated the motor onset and phenotype in these KOM2 mice, the MSA disease progression is excepted to be similar to that of hemizygous CNP-α-Syn transgenic mice on a wildtype α-Syn background. As described in Yazawa et al. Neuron (2005), mice that are hemizygous for the CNP-α-Syn transgene demonstrate progressive decline in brain weight starting at 7-9 months of age along with significant motor deficits as determined by rotarod performance. These hemizygous CNP-α-Syn mice also show a significant increase in glial cell inclusions (GCI) and insoluble α-synuclein aggregates in oligodendrocytes similar to human patients with multiple system atrophy (MSA). These KOM2 mice may be useful for studying the pathogenesis of synucleinopathies, specifically MSA.

Development

The KOM2 mice carry an α-Syn knock-out (KO) allele and a full-length human α-synuclein transgene (CNP-α-Syn M2 line).

The CNP-α-Syn transgene was generated using wildtype human α-synuclein cDNA, followed by bovine growth hormone polyadenylation sequence (bGh-PolyA), cloned into the Hind III site in exon 1 of the mouse 2',3'-cyclic nucleotide 3'-phosphodiesterase gene (Cnp), just upstream of the initiation codon. Purified linearized DNA was microinjected into the pronuclei of fertilized C57BL/6 x C3H F1 oocytes. Founder line M2 was established and maintained on a mixed C57BL/6;C3H genetic background. The transgene insertion site and copy number are unknown (January 2023).

The α-Syn knock-out allele (Stock No. 003692) was created by replacing exons 1-2 of the synuclein, alpha (Snca) gene with a neomycin resistance gene driven by a phosphoglycerate 1 promoter. The construct was electroporated into 129X1/SvJ-derived RW-4 embryonic stem (ES) cells. These two exons encode amino acids 1-41. Correctly targeted ES cells were injected into C57BL/6 blastocysts to generate mice and chimeric animals were obtained. The donating investigator obtained α-Syn knock-out mice directly from the Rosenthal lab and utilized these mice as noted below.

Homozygous CNP-α-Syn transgenics were crossed to homozygous α-Syn knockout mice to generate these KOM2 mice by the donating laboratory. Upon arrival at The Jackson Laboratory in 2023 (agouti coat color), sperm that was homozygous for the α-Syn targeted mutation and homozygous for the CNP-α-Syn transgene, was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize B6C3F1/J (Stock No. 100010) oocytes.

Allele

Symbol: Snca^tm1Rosl
Name: targeted mutation 1, Arnon Rosenthal
MGI accession ID: MGI:1888382
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: alpha-Syn^-; alpha-Synko
Marker symbol: Snca
Marker name: synuclein, alpha
Marker synonyms: alphaSYN; alpha-Syn; alpha-synuclein; NACP; PARK1; PARK4; PD1
Chromosome: 6
Strain of origin: 129X1/SvJ
Molecular note: A PGK-neo cassette was used to delete exons 1 and 2, encoding amino acids 1 through 41 as well as a 5' untranslated region. RT-PCR analysis of extracts from the brains of homozygous mutant mice, using probes for both the deleted 5' region as well the untargeted 3' region, showed an absence of transcript. Western blot analysis, immunohistochemical analysis, and in situ hybridization confirmed a lack of encoded protein in homozygous mutant mice.

Allele

Symbol: Tg(Cnp-SNCA)M2Vle
Name: transgene insertion M2, Virginia M Y Lee
MGI accession ID: MGI:5573154
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: alphaSyn CNP Tg
Marker symbol: Tg(Cnp-SNCA)M2Vle
Marker name: transgene insertion M2, Virginia M Y Lee
Marker synonyms: alphaSyn CNP Tg
Chromosome: UN
Strain of origin: (C57BL/6 x C3H)F1
Molecular note: The murine 2', 3'-cyclic nucleotide 3'-phosphodiesterase promoter drives expression of human wild-type alpha-synuclein in oligodendrocytes. Immunohistochemistry confirmed expression in oligodendrocytes.