B6.129-Slc24a2^tm1Jlyt/J

Stock number: 036984
Product name: NCKX2 KO

Research areas: Cell Biology Research, Neurobiology Research, Research Tools

Description

Nckx2 knock-out mice have a targeted disruption of exon 2 of the solute carrier family 24 (sodium/potassium/calcium exchanger) member 2 locus. Knock-out mice exhibit deficits in synaptic plasticity in CA1 pyramidal neurons as well as impairments in memory and locomotor activity. These mice may be useful in studying synaptic plasticity and learning and memory.

Detailed description

The Slc24a2 gene encodes the NCKX2 potassium-dependent sodium/calcium exchanger which plays a key role in neuronal homeostasis, particularly in hippocampal neurons, and is associated with motor learning and memory, as well as cone photoreceptor visual adaptation.

The NCKX2 knock-out allele (also called NCKX2^KO) has a neo cassette inserted into exon 2 of the Slc24a2 gene. Absence of full-length NCKX2 protein expression from the knock-out allele was confirmed by western blot of homogenized whole brain tissue. Homozygous mice exhibit deficits in learning and memory as assessed by accelerating rotorod and the alternating moving platform version of the Morris water maze task. Moreover, these mice show deficits in synaptic plasticity in pyramidal neurons of the CA1 region of the hippocampus (Li et al., 2006; PMID: 16407245). Otherwise, both heterozygous and homozygous mice are viable and fertile with no reported reproductive deficiency.

Development

The Nckx2 knock-out allele (also called Nckx2^KO) was created in the laboratory of Dr. Jonathan Lytton (University of Calgary). A targeting vector was designed to insert a neomycin resistance cassette in reverse orientation into exon 2 of the solute carrier family 24 (sodium/potassium/calcium exchanger), member 2 locus (Slc24a2) on chromosome 4. 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 recipient blastocysts, and chimeric mice were bred with C57BL/6J for germline transmission. The resulting Nckx2^KO colony was then backcrossed to C57BL/6J mice for at least 15 generations prior to sending males to The Jackson Laboratory Repository. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Of note, the donating investigator reports that the Y chromosome may not have been fixed to the C57BL/6J background during backcrossing.

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. Three of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Slc24a2^tm1Jlyt
Name: targeted mutation 1, Johathan Lytton
MGI accession ID: MGI:3663782
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Nckx2^-
Marker symbol: Slc24a2
Marker name: solute carrier family 24 (sodium/potassium/calcium exchanger), member 2
Marker synonyms: 6330417K15Rik; NCKX2
Chromosome: 4
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A targeting vector was designed to replace part of exon 2 with a neomycin resistance cassette in reverse orientation. Transcript was not detected in Northern blot of mutant brains. Immunoblot failed to detect protein in mutant brain samples.