B6.129S2-Oprk1^tm1Kff/J

Stock number: 007558
Product name: KOR-
Research areas: Neurobiology Research, Research Tools, Sensorineural Research

Description

These Oprk1 knock-out mice may be useful in studying biological activity of opioids, analgesics, spinally mediated thermal nociception and chemical visceral pain thresholds.

Detailed description

Mice homozygous for this kappa-opioid receptor mutant allele (KOR-) are viable and fertile. KOR-selective ligand binding is absent on brain membranes from homozygous mice. In contrast to mutant mice deficient of delta- or mu-opioid receptors (Stock No. 007557 or 007559), KOR- homozygotes have normal mechanical pain thresholds, but greatly increased sensitivity to chemical visceral pain. KOR- homozygotes also exhibit normal spontaneous stress responses (unlike delta-opioid receptor null mice). Homozygous KOR- mice also show decreased ethanol self-administration and decreased THC-conditioned place aversion. These KOR mutant mice may be useful in studying biological activity of opioids, analgesics, spinally mediated thermal nociception and chemical visceral pain thresholds.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. These mutant mice were originally published on a mixed genetic background. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

Development

A targeting vector was designed to replace a portion of the first exon (containing the translation initiation codon) of the targeted gene with a PGK-neo cassette. The construct was electroporated into 129S2/SvPas-derived P1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric males were bred with C57BL/6 females. These kappa-opioid receptor (KOR) mutant mice were backcrossed to C57BL/6J inbred mice for at least 12 generations prior to arrival at The Jackson Laboratory. The Y chromosome may not have been fixed to the C57BL/6J genetic background.

Allele

Symbol: Oprk1^tm1Kff
Name: targeted mutation 1, Brigitte L Kieffer
MGI accession ID: MGI:2387031
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Oprk1
Marker name: opioid receptor, kappa 1
Chromosome: 1
Strain of origin: 129S2/SvPas
Molecular note: Exon 1 was disrupted by the insertion of a neomycin selection cassette. The insertion deleted sequence encoding amino acids 1 through 79. A radiolabeled binding assay demonstrated a lack of endogenous function.