B6;129-Oprk1^tm2.1Kff/J

Stock number: 030076
Product name: KOR^lox
Research areas: Neurobiology Research, Research Tools

Description

Oprk1^lox/lox mice possess loxP sites flanking exon 3 of the opioid receptor, kappa 1 (Oprd1) gene. These mice may be useful in studying mood disorders and addiction.

Detailed description

Oprk1^lox/lox floxed mice possess loxP sites flanking exon 3 of the opioid receptor, kappa 1 (Oprk1) gene. κ-opioid receptors (KORs) are G-protein-coupled receptors that inhibit neuronal activity upon binding of ligands such as dynorphin and other opioids. KORs are targets for the treatment of depression, alcohol dependence, and opiate addiction. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 3 deleted in cre-expressing tissues.

When bred to DAT-Cre mice, expressing Cre Recombinase in dopaminergic neurons, resulting mice lack κ-opioid receptors specifically in these neurons.

Development

The Oprk1^lox/lox targeting vector was designed to insert a loxP-flanked hygromycin resistance (hygro) cassette upstream of exon 3 and a third loxP site downstream of exon 3 of the opioid receptor, kappa 1 (Oprd1) gene. Previously it was reported that exon 1 was floxed, but it was later determined that exon 3 is floxed. The construct was electroporated into 129Sv-derived embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a Cre expression plasmid to delete the hygro cassette. Resulting ES cells contained multiple gene rearrangments; intact floxed-exon 1, intact floxed-hygro cassette, or excision of exon 1 and the hygro cassette. Correctly targeted ES cells, containing only the floxed-exon 1, were injected into C57BL/6J blastocysts and chimeric males were bred with C57BL/6J females. Resulting Oprk1^lox/lox mice were bred to (C57BL/6J x 129) F1 mice for at least 5 generations. 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).

Allele

Symbol: Oprk1^tm2.1Kff
Name: targeted mutation 2.1, Brigitte L Kieffer
MGI accession ID: MGI:5823257
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: KOR^lox
Marker symbol: Oprk1
Marker name: opioid receptor, kappa 1
Marker synonyms: KOP; KOR; KOR1; K-OR-1; KOR-1; OPRK; Oprk2; R21
Chromosome: 1
Strain of origin: 129
Molecular note: The targeting vector is designed to insert a loxP-flanked hygromycin resistance (hygro) cassette upstream of exon 3 and a third loxP site downstream of exon 3. Transient transfection with a cre expression plasmid removed the loxP-flanked hygromycin cassette leaving exon 3 floxed.