STOCK Kcnq3^tm1.1Avtz/J

Stock number: 036076
Product name: Kcnq3^fl
Research areas: Mouse/Human Gene Homologs, Neurobiology Research, Research Tools

Description

Kcnq3^fl mutant mice possess loxP sites flanking exons 2-4 of the epilepsy-associated Kcnq3 (potassium voltage-gated channel, subfamily Q, member 3) gene and may be useful in generating conditional mutations to study the regulation of neuronal excitability.

Detailed description

Kcnq3 (potassium voltage-gated channel, subfamily Q, member 3) encodes an integral membrane protein that associates with Kncq2 to form the M current, a potassium channel involved in the regulation of pyramidal neuron excitability and spike behavior. Mutations in Kcnq3 are associated with some types of epilepsies. These conditional Kcng3^fl mice possess loxP sites flanking exons 2-4 of the Kcnq3 gene. Mice homozygous for the mutation are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have the exons 2-4 deleted in cre-expressing tissues. This strain may be useful for studies involving the regulation of patterning of the cerebral cortex.

For example, when bred to mice with Cre recombinase expression in the cerebral cortex (Emx1^tm1(cre)Krj, Stock No. 005628), resulting knockout offspring exhibit a reduction in the M current.

Development

The targeting construct was designed to insert a loxP site downstream of exon 1 and an FRT-flanked neomycin cassette followed by a second loxP site downstream of exon 4 of the Kcnq3 gene on chromosome 17. Exons 2-4 include sequence encoding the pore region of the Kcnq3 potassium channel. The construct was electroporated into (C57BL/6Jx129/Sv)F1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. Chimeric males were crossed to B6.129S4-Gt(ROSA)26Sor^tm1(FLP1)Dym females (ROSA26-Flpe) to delete the neo cassette. The resulting progeny were crossed to remove the FLP-expressing transgene. The colony was crossed to C57BL/6J for at least 5 generations by the donating laboratory (see SNP note below). Upon arrival, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

In 2021, a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 males sent to The Jackson Laboratory Repository. Four of the 43 markers throughout the genome were segregating with 129 and two markers, on Chromosome 17, were segregating with an unknown source. Also, two of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.

Allele

Symbol: Kcnq3^tm1.1Avtz
Name: targeted mutation 1.1, Anastasios V Tzingounis
MGI accession ID: MGI:5607736
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Kcnq3^fl
Marker symbol: Kcnq3
Marker name: potassium voltage-gated channel, subfamily Q, member 3
Marker synonyms: BFNC2; EBN2; KV7.3
Chromosome: 15
Strain of origin: (C57BL/6J x 129/Sv)F1
Molecular note: Exons 2-4 were floxed and an FRT flanked neomycin cassette was inserted via homologous recombination. Flp mediated recombination removed the neomycin cassette.