Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. The Donating Investigator reports that the expected number of homozygotes are produced in heterozygous crosses. No gene product (mRNA) is detected by RT-PCR analysis of brain tissue from homozygotes. SNP analysis revealed that the Oprm1 allele variant, which is located close to the targeted gene, is from C57BL/6. Homozygotes exhibit increased phosphatase 1 activity in the thalamus. Homozygotes develop faster morphine tolerance in a hot plate assay ("supraspinal" nociceptive response assessment) and a rightward shift in dose response curve for morphine reward in conditioned place preference when compared to wildtype controls.
A neo cassette-containing targeting vector was used to disrupt exon 1, which contains the initiation codon and the potential PP1 docking motif. The construct was electroporated into 126S6/SvEvTac derived MC1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts. The resulting heterozygous chimeric animals were intercrossed to generate homozygotes. SNP analysis revealed that the Oprm1 allele variant, which is located close to the targeted gene, is from C57BL/6. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 1, George R Uhl|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Ppp1r14c, protein phosphatase 1, regulatory inhibitor subunit 14C|
|Strain of Origin||129S6/SvEvTac|
|General Note||The original line on a mixed 129S6/SvEvTac and C57BL/6 background was discontinued in favor of a recombinant line containing regions adjacent to the targeted allele from C57BL/6 (J:159561).|
|Molecular Note||Exon 1 was replaced with a neo cassette. RT-PCR confirmed the absence of transcript expression.|
|Mutations Made By|| |
George Uhl, NIDA-IRP/NIH
When maintaining a live colony, these mice can be bred as homozygotes. The Donating Investigator reports that the expected number of homozygotes are produced in heterozygous crosses.
When using the B6;129S6-Ppp1r14ctm1Uhl/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #013041 in your Materials and Methods section.