B6.129(SJL)-Scn4b^tm1.1Geh/RahJ

Stock number: 027530
Product name: Scn4b floxed
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

Scn4b floxed mice may be useful for studying the role of sodium channel beta subunits on the gating properties of sodium channels.

Detailed description

Scn4b floxed mice possess loxP sites flanking exon 2 of the sodium channel, type IV, beta (Scn4b) gene. SCN4B encodes a sodium channel beta subunit, expressed in the dorsal and ventral striatum, that interacts with voltage-gated alpha subunits to alter the gating properties of sodium channels. Mice that are homozygous for this allele are viable and fertile.

When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues.
For example, when bred to B6.FVB-Tg(EIIa-cre)C5379Lmgd/J (Stock No. 003724) expressing germline Cre Recombinase, resulting Scn4b KO offspring show a reduction of spike-timing-dependent long-term depression (tLTD) in medium spiny neurons (MSNs), with no effect on long-term potentiation (tLTP). These changes in action potential reduce the ability of backpropagating action potentials to evoke calcium signals in dendrites of MSNs.

Development

A targeting vector was designed to insert a loxP site, followed by a frt-flanked neomycin resistance (neo) cassette, upstream of exon 2, and a second loxP site downstream of exon 2 of the sodium channel, type IV, beta (Scn4b) gene. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6NCrl embryos and resulting chimeric males were bred to C57BL/6J females. Offspring were bred with B6.Cg-Tg(ACTFLPe)9205Dym/J transgenic mice (Stock No. 005703) to delete the neo cassette. Progeny were bred to C57BL/6J mice to remove the Flp-expressing transgene, resulting in a colony of Scn4b floxed mice. These mice were backcrossed to C57BL/6J mice for at least 3 more generations. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Scn4b^tm1.1Geh
Name: targeted mutation 1.1, Gregg E Homanics
MGI accession ID: MGI:5634084
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Scn4b
Marker name: sodium channel, type IV, beta
Chromosome: 9
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A targeting vector was designed to insert a loxP site, followed by a FRT-flanked neomycin resistance (neo) cassette, upstream of exon 2, and a second loxP site downstream of exon 2. Flp-mediated recombination removed the FRT-flanked neo cassette leaving exon 2 floxed.