FVB.Cg-Tg(SMN2*A111G)588Ahmb Tg(SMN2-SMN1*Q282A)2Ahmb Smn1^tm1Msd/J

Stock number: 031909
Product name: SMN2 A111G; SMN2 Q282A; Smn1 KO
Research areas: Neurobiology Research

Description

These triple mutant mice (SMN A111G +/+; SMN Q282A+/+; KO+/+) harbor the Smn1^tm1Msd null allele, the Tg(SMN2*A111G)588Ahmb transgene, and the Tg(SMN2-SMN1*Q282A)2Ahmb designed to introduce the Q282A missense mutation in exon 7 of the human SMN1 gene. This mutant mouse strain may be useful in studies of spinal muscular atrophy.

The Tg(SMN2*A111G)588Ahmb transgene integrated on chromosome 8 (119838039-119852117; mouse mm10) and resulted in a 14 kb genomic region duplication that includes exons 1 and 2 of the Cotl1 locus. It is not known if the duplicated region expresses any Cotl1 isoforms or truncated protein.

The Tg(SMN2-SMN1*Q282A)2Ahmb transgene integrated on chromosome 11 (70055009-70372513; mouse mm10) and resulted in a 317 kb genomic region duplication that includes several loci (Asgr1, Asgr2, Mgl2, Clec10a, Slc16a11, Slc16a13, Bcl6b, Mir497b, Rnasek, Alox12 and Alox15). Therefore, Tg(SMN2-SMN1*Q282A)2Ahmb mice and can be expected to have overexpression of those duplicated loci in hemizygotes, and to a greater extent in homozygotes.

Detailed description

These triple mutant mice carry the Smn1^tm1Msd knock-out null allele, the Tg(SMN2*A111G)588Ahmb transgene, and the Tg(SMN2-SMN1*Q282A)2Ahmb missense mutant transgene.

No endogenous Smn1 expression is observed from the Smn1^tm1Msd knock-out null allele. Expression of the Tg(SMN2*A111G)588Ahmb in founder line 588 is detected in the spinal cord, forebrain and liver by RT-PCR. The Tg(SMN2-SMN1*Q282A)2Ahmb transgene contains the Q282A missense mutation in exon 7. Tg(SMN2-SMN1*Q282A)2Ahmb transgene mRNA expression is detected in brain and spinal cord tissue by RT-PCR analysis and in spinal cord by western blot analysis; expression has not been examined in any other tissues. The Donating Investigator notes that the mice may be scruffy in appearance. Triple homozygous mice are viable and fertile. As the mice are characterized, we will modify the strain description and add phenotype data.

The donating investigator reported that mice hemizygous for the Tg(SMN1*A111G)2Ahmb transgene carry 4 copies and mice homozygous for the Tg(SMN1*A111G)2Ahmb transgene carry 8 copies. See below for transgene insertion information.

The donating investigator reported that mice hemizygous for the Tg(SMN2-SMN1*Q282A)2Ahmb transgene carry 4 copies and mice homozygous for the Tg(SMN2-SMN1*Q282A)2Ahmb transgene carry 8 copies. Additionally, they reported that the Tg(SMN2-SMN1*Q282A)2Ahmb transgene copy number is stable. See below for transgene insertion information.

Tg(SMN2*A111G)588Ahmb transgene insertion information: In October 2019, sequencing performed by The Jackson Laboratory discovered that three or more copies of the Tg(SN2*A111G)588Ahmb transgene integrated on chromosome 8 (119838039-119852117; mouse mm10) and resulted in a duplication of the 14 kb genomic region in between the two identified fusion points. This duplicated region includes exons 1 and 2 of the Cotl1 locus. It is not known if the duplicated region expresses any Cotl1 isoforms or truncated protein. Of note, endogenous Cotl1 has up to 5 exons, and exon 1 contains the ATG site in all 3 protein-coding transcripts [Ensembl GRCm38.p6].

Tg(SMN2-SMN1*Q282A)2Ahmb transgene insertion information: In October 2019, sequencing performed by The Jackson Laboratory discovered that the Tg(SMN2-SMN1*Q282A)2Ahmb transgene integrated on chromosome 11 (70055009-70372513; mouse mm10) and resulted in a duplication of the 317 kb genomic region in between the two identified fusion points. This duplicated region includes several loci (Asgr1, Asgr2, Mgl2, Clec10a, Slc16a11, Slc16a13, Bcl6b, Mir497b, Rnasek, Alox12 and Alox15). Therefore, Tg(SMN2-SMN1*Q282A)2Ahmb mice and can be expected to have overexpression of those duplicated loci in hemizygotes, and to a greater extent in homozygotes. The transgene copy number for homozygous mice was estimated to be greater than eight.

Development

These SMN A111G +/+; SMN Q282A+/+; KO+/+ mice harbor several mutations/transgenes, as described below.

The Smn1 null allele (Smn1^tm1Msd) was created in the laboratory of Dr. Michael Sendtner at the University of Wurzburg, Germany. Exon 2 of the endogenous mouse Smn gene was disrupted by employing a targeting vector encoding a neomycin cassette and a lacZ gene fused to the first 40 nucleotides of the disrupted exon to permit expression of the lacZ gene in tissues where Smn is normally expressed. The construct was electroporated into 129P2/OlaHsd-derived E14Tg2a-IV embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and chimeric animals obtained. Chimeric animals were crossed to C57BL/6 for several (unspecified number) of generations.

Both transgenes were created in the laboratory of Dr. Arthur Burghes at Ohio State University.
The SMN(A111G) transgene was designed with the SMN(A111G) missense mutation under the control of the 4.1 kb SMN promoter derived from the human SMN2 gene. This transgene was injected into fertilized FVB/N mouse oocytes. The donating investigator reported that founder animal 588, bearing 4 copies of the transgene, was obtained. See below for transgene insertion information.
The Tg(SMN2-SMN1*Q282A)2Ahmb transgene was designed with a human SMN1 cDNA carrying the Q282A missense mutation in exon 7 under the control of the 4.1 kb SMN promoter derived from the SMN2 gene. This transgene was microinjected into fertilized FVB/N oocytes. The donating investigator reported that founder line 2, bearing 4 copies of the transgene (as hemizygote), was obtained. They also reported that the Tg(SMN2-SMN1*Q282A)2Ahmb transgene copy number is stable. See below for transgene insertion information.

The triple mutant line was maintained on a FVB background, and then sent to The Jackson Laboratory in 2018. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize FVBN/J (Stock No. 001800). Triple homozygous embryos were later cryopreserved.

Tg(SMN2*A111G)588Ahmb transgene insertion information: In October 2019, sequencing performed by The Jackson Laboratory discovered that three or more copies of the Tg(SMN2*A111G)588Ahmb transgene integrated on chromosome 8 (119838039-119852117 [mouse mm10) and resulted in a duplication of the 14 kb genomic region in between the two identified fusion points. This duplicated region includes exons 1 and 2 of the Cotl1 locus. It is not known if the duplicated region expresses any Cotl1 isoforms or truncated protein. Of note, endogenous Cotl1 has up to 5 exons, and exon 1 contains the ATG site in all 3 protein-coding transcripts [Ensembl GRCm38.p6].

Tg(SMN2-SMN1*Q282A)2Ahmb transgene insertion information: In October 2019, sequencing performed by The Jackson Laboratory discovered that the Tg(SMN2-SMN1*Q282A)2Ahmb transgene integrated on chromosome 11 (70055009-70372513 [mouse mm10) and resulted in a duplication of the 317 kb genomic region in between the two identified fusion points. This duplicated region includes several loci (Asgr1, Asgr2, Mgl2, Clec10a, Slc16a11, Slc16a13, Bcl6b, Mir497b, Rnasek, Alox12 and Alox15). Therefore, Tg(SMN2-SMN1*Q282A)2Ahmb mice and can be expected to have overexpression of those duplicated loci in hemizygotes, and to a greater extent in homozygotes. The transgene copy number for homozygous mice was estimated to be greater than eight.

Allele

Symbol: Tg(SMN2*A111G)588Ahmb
Name: transgene insertion 588, Arthur H M Burghes
MGI accession ID: MGI:3847324
Generation method: Transgenic
Attributes: Inserted expressed sequence
Synonyms: A588; A591; line 588; line 591; SMN(A111G)
Marker symbol: Tg(SMN2*A111G)588Ahmb
Marker name: transgene insertion 588, Arthur H M Burghes
Marker synonyms: A588; A591; line 588; line 591; SMN(A111G)
Chromosome: 8
Strain of origin: FVB/N
Expressed genes: SMN2,survival of motor neuron 2, centromeric,human
Molecular note: A transgenic construct containing the SMN(A111G) missense mutation under the control of 4.1 kb SMN promoter was injected into fertilized FVB/N mouse eggs. Eleven founder lines were obtained and line 588 was subsequently established. This line was found to have 4 copies of the transgene. The transgene integrated on chromosome 8 (119838039-119852117; mouse mm10]), which resulted in a duplication of the 14 kb genomic region in between the two identified fusion points. This duplicated region includes exons 1 and 2 of the Cotl1 locus. It is not known if the duplicated region expresses any Cotl1 isoforms or truncated protein.

Allele

Symbol: Smn1^tm1Msd
Name: targeted mutation 1, Michael Sendtner
MGI accession ID: MGI:2183946
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Synonyms: SMN^-
Marker symbol: Smn1
Marker name: survival motor neuron 1
Marker synonyms: BCD541; C-BCD541; GEMIN1; SMA; SMA@; SMA1; SMA2; SMA3; SMA4; Smn; SMNC; SMNT; T-BCD541; TDRD16A; TDRD16B
Chromosome: 13
Strain of origin: 129P2/OlaHsd
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: The expression of the lacZ gene in tissues where Smn is normally expressed was noted.
Molecular note: A lacZ-neo cassette was inserted into exon 2 by homologous recombination resulting in an in-frame fusion of lacZ to exon 2. Homozygous mutant embryos were identified up to 80 hours post coitum. The expression of the lacZ gene in tissues where Smn is normally expressed was noted.

Allele

Symbol: Tg(SMN2-SMN1*Q282A)2Ahmb
Name: transgene insertion 2, Arthur H M Burghes
MGI accession ID: MGI:6189119
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: SMNQ282A
Marker symbol: Tg(SMN2-SMN1*Q282A)2Ahmb
Marker name: transgene insertion 2, Arthur H M Burghes
Chromosome: 11
Strain of origin: FVB/N
Molecular note: The transgenic construct contains a human SMN1 cDNA carrying the p.Gln282Ala missense mutation in exon 7 under the control of a 4.1 kb SMN promoter derived from the SMN2 gene. Founder line 2 carries eight copies of the transgene. The transgene integrated on chromosome 11 (70055009-70372513; mouse mm10]) resulting in a duplication of the 317 kb genomic region between the two identified fusion points. This duplicated region includes several loci (Asgr1, Asgr2, Mgl2, Clec10a, Slc16a11, Slc16a13, Bcl6b, Mir497b, Rnasek, Alox12 and Alox15).