B6.Cg-Tg(Prnp-TARDBP*Q331K)103Dwc/J

Stock number: 017933
Product name: Prp-TDP-43^Q331K line 103
Research areas: Mouse/Human Gene Homologs, Neurobiology Research, Research Tools

Description

Prp-TDP-43^Q331K [~1.5x] transgenic line 103 mice have expression of a myc-tagged, human TAR DNA binding protein carrying the ALS-linked Q331K mutation (huTDP-43*Q331K) directed to brain and spinal cord by the mouse prion protein promoter. Along with the lower huTDP-43*Q331K expressing founder line (Prp-TDP-43^Q331K-low; Stock No. 017930), these Prp-TDP-43^Q331K [~1.5x] transgenic mice may be useful in studying motor dysfunction in the neurodegenerative disorder amyotrophic lateral sclerosis (ALS; Lou Gehrig's Disease), specifically motor dysfunction and L5 motor axon/lower motor neuron degeneration.

Please see Detailed Description section for information regarding transgene copy number.

Detailed description

Prp-TDP-43^Q331K line 103 transgenic mice express a myc-tagged, human TAR DNA binding protein cDNA sequence modified to have the ALS-linked Q331K mutation (huTDP-43*Q331K), all under the direction of the mouse prion protein promoter (PrP). As expected for the PrP promoter, transgene expression is confined primarily to central nervous system (brain and spinal cord), with very low to no expression in other tested tissues (testis not examined). Anti-myc antibody staining shows huTDP-43*Q331K accumulation in the nuclei of neurons as well as glial cells of the spinal cord and brain, with a corresponding downregulation of endogenous mouse TDP-43. The transgene is flanked by loxP sites, allowing it to be removed by introduction of Cre recombinase if desired. The phenotype below describes Prp-TDP-43^Q331K transgenic mice from founder line 103 (Prp-TDP-43^Q331K [~1.5x]).

The Prp-TDP-43^Q331K [~1.5x] mice have moderate overexpression levels in total TDP-43 mRNA/protein, with an ~2.5-fold increase in total TDP-43 expression (huTDP-43*Q331K levels ~1.5-fold greater) compared to endogenous TDP-43 in non-transgenic mice. By three months of age, Prp-TDP-43^Q331K [~1.5x] mice develop adult-onset motor dysfunction (as measured by rotarod performance) accompanied by a loss of hindlimb-grip strength and the appearance of muscle fasciculations. Pathologically, Prp-TDP-43^Q331K [~1.5x] mice demonstrate ~30% loss of L5 motor axons and 30-45% loss of lower motor neurons by ten months of age (earlier timepoints not yet tested; May 2012). Of note, this latter phenotype is in contrast to Dr. Robert Baloh's Prp-TDP43^A315T transgenic mice that primarily display a loss of upper motor neurons (Stock No. 010700). Also note, this is in contrast to the founder line with low huTDP-43*Q331K overexpression (Prp-TDP-43^Q331K-low line 109; Stock No. 017930), that do not exhibit loss of motor axons or neurons.

Important Note regarding transgene copy number: In March 2023, quality control analyses performed by The Jackson Laboratory concluded that Stock No. 017933 hemizygous mice from the live colony harbor ~4 copies of the transgene. Specifically, eleven hemizygous mice across seven different pedigree lineages in the live colony were sampled for ddPCR, the results showed a ddPCR copy number range of 3.88-4.36.

Development

A full-length human TAR DNA binding protein (TARDBP or TDP-43) cDNA sequence was modified to have both an N-terminal myc tag and the glutamine to lysine substitution at amino acid 331 associated with familial ALS (huTDP-43*Q331K). This huTDP-43*Q331K cDNA sequence was inserted between exon 2 and exon 3 of mouse prion protein (PrP or Prnp) gene at two unique XhoI sites in the MoPrP.XhoI plasmid vector (ATCC#JHU-2). The resulting MoPrP.XhoI-^mychuTDP-43*Q331K transgene was flanked with loxP sites, and then injected into the pronuclei of fertilized C57BL6/C3H hybrid eggs, which were implanted into pseudopregnant female mice. Transgenic founder mice were bred to C57BL/6 mice, and founder line 103 was identified with ~2.5-fold greater total TDP-43 (~1.5-fold greater huTDP-43*Q331K) expression levels in spinal cord as compared to endogenous TDP-43 in non-transgenic mice. These Prp-TDP-43^Q331K [~1.5x] transgenic mice were bred with C57BL/6NCrl females for at least nine generations prior to sending to The Jackson Laboratory in 2012 (see SNP note below). Upon arrival, transgenic mice were bred to C57BL/6NJ inbred mice (Stock No. 005304) for at least one generation to establish The Jackson Laboratory colony. Since then, our live colony has additionally been backcrossed to C57BL/6NJ for 2-3 generations (January 2023).

From this strain's arrival in 2012 through 2016, our 32 SNP (single nucleotide polymorphism) panel, with 27 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 Stock No. 017933 rederived living colony at The Jackson Laboratory. As expected, this showed all SNPs as C57BL/6 genetic background with all C57BL/6 substrain markers as C57BL/6N allele-type.
Beginning in 2017 to present (2021), The Jackson Laboratory has employed an expanded 48 SNP panel that includes several new markers. These results again showed all markers as C57BL/6 allele-type. In addition, all C57BL/6 substrain markers were C57BL/6N allele-type with one exception - the new marker on chromosome 6 [~107.8 Mbp] shows some C57BL/6N or C57BL/6J allele-type. Importantly, this new chromosome 6 SNP has previously shown that C57BL/6NCrl allele-type is the same as C57BL/6J allele-type (rather than C57BL/6NJ allele-type). Taken together, this strongly suggests that the live colony of Stock No. 017933 is a mix of C57BL/6NJ;C57BL/6NCrl.

Allele

Symbol: Tg(Prnp-TARDBP*Q331K)103Dwc
Name: transgene insertion 103, Don W Cleveland
MGI accession ID: MGI:5463119
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: Prp-TDP-43^Q331K
Marker symbol: Tg(Prnp-TARDBP*Q331K)103Dwc
Marker name: transgene insertion 103, Don W Cleveland
Chromosome: UN
Strain of origin: C57BL/6 x C3H
Expressed genes: TARDBP,TAR DNA binding protein,human; myc tag,myc tag,
Molecular note: A full-length human TAR DNA binding protein (TARDBP or TDP-43) cDNA sequence was modified to have both an N-terminal myc tag and the glutamine to lysine substitution at amino acid 331 associated with familial ALS (huTDP-43*Q331K). This huTDP-43*Q331K cDNA sequence was inserted between exon 2 and exon 3 of mouse prion protein (Prnp) gene. The resulting Prnp-TDP-43*Q331K transgene was flanked with loxP sites. Founder line 103 was identified with approxiamately 2.5-fold greater total TDP-43 (1.5-fold greater huTDP-43*Q331K) expression levels in spinal cord as compared to endogenous TDP-43 in non-transgenic mice.