B6.129S6-Tg(CAG-Bgeo,-SMN2)E9Dscd/J

Stock number: 018439
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

These Tg hSMN2 E9 inducible SMN transgenic mice conditionally express a human SMN2 cDNA. Widespread lacZ expression is observed except in those tissues where cre recombination has resulted in the human SMN2 cDNA to be expressed instead. These transgenic mice are suitable for use in studies related to Spinal Muscular Atrophy.

Detailed description

These Tg hSMN2 E9 inducible SMN transgenic mice have a loxP-flanked β-geo STOP cassette preventing transcription of a downstream full-length human SMN2 cDNA sequence (exons 1-8). Prior to Cre recombinase exposure, β-galactosidase (lacZ) expression is directed to widespread tissues by the CMV-IE enhancer/chicken β-actin/rabbit β-globin hybrid promoter, and no human SMN2 expression is observed. When bred to mice that express Cre recombinase, the resulting offspring will have the floxed β-geo STOP cassette deleted in the cre-expressing tissues; resulting in expression of full-length human SMN2 in cre-expressing tissues (and continued lacZ expression in other tissues). The donating investigator reports that Tg hSMN2 E9 inducible SMN transgenic mice do not express human SMN2 prior to introduction of Cre recombinase. Mice hemizygous for the inducible SMN transgene are viable and fertile, with no reported phenotypic abnormalities. The phenotype of homozygous mice has not been characterized by the donating investigator to date (May 2012). These Tg hSMN2 E9 inducible SMN transgenic mice allow induction of full-length SMN2 cDNA after Cre-mediated recombination, and are suitable for use in studies related to Spinal Muscular Atrophy.

Development

The pCCALL2/hSMN2 transgene was designed with, from 5' to 3', the CMV-IE enhancer/chicken β-actin/rabbit β-globin hybrid promoter (originally from the pCAGG vector), a loxP-flanked STOP cassette (β-galactosidase/neomycin resistance cassette [β-geo] with three copies of the SV40 polyA signal), the 1.37 kbp full-length human SMN2 cDNA sequence including all exons (1-8) from the start codon to the stop codon, and a rabbit polyA signal. The 1.37 kbp human SMN2 cDNA sequence (encoding exons 1-8) was originally derived via RT-PCR performed on total RNA isolated from SMA type 1-derived patient fibroblast cells (Coriell Institute GM 3813; shown to express both full-length and truncated SMN2 transcripts). The transgene was electroporated into 129S6/SvEvTac-derived TC1 embryonic stem (ES) cells. ES cell clone E9 was identified with a single insertion site and high expression of the lacZ reporter. Clone E9 was injected into blastocysts, which were then implanted into pseudopregnant females. Chimeric offspring were bred to C57BL/6J mice to establish the colony. Transgene positive (Tg hSMN2 E9) mice were then bred to C57BL/6J mice for at least ten additional generations prior to sending to The Jackson Laboratory Repository. Upon arrival, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish The Jackson Laboratory Repository colony.

Allele

Symbol: Tg(CAG-Bgeo,-SMN2)E9Dscd
Name: transgene insertion E9, Dawn S Chandler
MGI accession ID: MGI:5427354
Generation method: Transgenic
Attributes: Conditional ready (e.g. floxed); Reporter; Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(CAG-Bgeo,-SMN2)E9Dscd
Marker name: transgene insertion E9, Dawn S Chandler
Chromosome: UN
Strain of origin: 129S6/SvEvTac
Expressed genes: Bgeo,fusion of beta-galactosidase and neomycin phosphotransferase genes,E. coli; SMN2,survival of motor neuron 2, centromeric,human
Site of expression: lacZ expression is seen in all cells prior to Cre recombination. After cre excision of the floxed- lacZ-neo cassette, human SMN2 is expressed in cre-expressing tissues.
Molecular note: The pCCALL2/hSMN2 transgene was designed with, from 5' to 3', the CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (originally from the pCAGG vector), a loxP-flanked STOP cassette (beta-galactosidase/neomycin resistance cassette [beta-geo] with three copies of the SV40 polyA signal), the 1.37 kbp full-length human SMN2 cDNA sequence including all exons (1-8) from the start codon to the stop codon, and a rabbit polyA signal. The 1.37 kbp human SMN2 cDNA sequence (encoding exons 1-8) was originally derived via RT-PCR performed on total RNA isolated from SMA type 1-derived patient fibroblast cells (Coriell Institute GM 3813; shown to express both full-length and truncated SMN2 transcripts). Lines A9 and E9 was generated.