B6.129(SJL)-Kcnk9^tm1.2Daba/J

Stock number: 026191
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

Kcnk9^f/f floxed mice may be useful for studying pH sensitivity and chemosensitivity in respiratory neurons.

Detailed description

Kcnk9^f/f floxed mice possess loxP sites flanking exon 2 of the potassium channel, subfamily K, member 9 (Kcnk9) gene. Kckn9 is a pH-dependent, voltage-insensitive potassium channel that mediates background potassium currents responsible for setting resting membrane potential. Kcnk9 is expressed in cerebellar granule cells, locus coeruleus, motor neurons, pontine nuclei, some cells in the neocortex, habenula, olfactory bulb granule cells, and cells in the external plexiform layer of the olfactory bulb. Mice that are homozygous for this allele are viable and fertile. 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.

When bred to Tg(Hsp70-1-cre)1Arge mice expressing cre at the 2 cells stage, Kcnk9^-/- mice are normal. When bred to Kcnk3^f/f mice (Stock No. 026191) prior to cre-excision, double KO mice exhibit phenotypic similarity to the human syndrome bilateral idiopathic primary hyperaldosteronism,caused by an increase in aldosterone production by the adrenal glands that is resistant to salt suppression.

Development

A targeting vector was designed to insert a frt-flanked neomycin resistance (neo) cassette followed by a loxP site upstream of exon 2, and a second loxP site downstream of exon 2 of the potassium channel, subfamily K, member 9 (Kcnk9) 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 blastocysts and resulting chimeric mice were bred to C57BL/6J mice. Mice were backcrossed to C57BL/6J mice using a speed congenic protocol for many generations. Offspring were bred with B6.Cg-Tg(ACTFLPe)9205Dym/J transgenic mice (Stock No. 005703) to delete the neo cassette, and progeny were crossed to remove the Flp-expressing transgene. Resulting Kcnk9^f/f mice also contained the Kcnk3^tm1.2Daba floxed allele. The Kcnk3^fl/fl allele was bred out of the colony and maintained as a Stock No. 025928. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Kcnk9^tm1.2Daba
Name: targeted mutation 1.2, Douglas A Bayliss
MGI accession ID: MGI:5588402
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Kcnk9
Marker name: potassium channel, subfamily K, member 9
Chromosome: 15
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Site of expression: Kcnk9 is expressed in cerebellar granule cells, locus coeruleus, motor neurons, pontine nuclei, some cells in the neocortex, habenula, olfactory bulb granule cells, and cells in the external plexiform layer of the olfactory bulb.
Molecular note: A targeting vector was designed to insert a frt-flanked neomycin resistance (neo) cassette followed by a loxP site upstream of exon 2, and a second loxP site downstream of exon 2. Flpe mediated recombination removed the FRT-flanked neo cassette leaving exon 2 floxed.