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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Oprm1tm1Loh
targeted mutation 1, Horace H Loh
MGI:2388673
Summary 5 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Oprm1tm1Loh/Oprm1tm1Loh involves: 129P2/OlaHsd MGI:3625861
hm2
Oprm1tm1Loh/Oprm1tm1Loh involves: 129P2/OlaHsd * BALB/c * C57BL/6 MGI:3619218
hm3
Oprm1tm1Loh/Oprm1tm1Loh involves: 129P2/OlaHsd * BALB/cJ * C57BL/6J MGI:3619220
hm4
Oprm1tm1Loh/Oprm1tm1Loh involves: 129P2/OlaHsd * C57BL/6 * DBA/2 MGI:3625887
ht5
Oprm1tm1Loh/Oprm1+ involves: 129P2/OlaHsd MGI:3625879


Genotype
MGI:3625861
hm1
Allelic
Composition
Oprm1tm1Loh/Oprm1tm1Loh
Genetic
Background
involves: 129P2/OlaHsd
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Loh mutation (0 available); any Oprm1 mutation (53 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• a dose of morphine (400 mg/kg) that is lethal to wild-type mice did not cause death of any mutant animals; the LD50 of morphine in homozygotes is much higher than 800 mg/kg
• homozygotes die within 2 hours at doses of 1600 mg/kg without typical morphine effects, suggesting reasons other than morphine toxicity

behavior/neurological
• repeated administration of cocaine induces robust behavioral sensitization in mutant mice on day6 which is maintained through day 12: acute cocaine treatment significantly decreases locomotor activity in mutants
• at 800 mg/kg of morphine, homozygotes do not display the usual morphine effects like Straub tail or increased locomotor activity, like heterozygotes (J:47187)
• repeated administration of morphine fails to induce behavioral sensitization in mutant mice on days 6 and 12; locomotor activity in response to morphine is similar to saline treatment on day 1 (J:107973)
• null mice exhibit memory impairment in both the hidden platform and probe trial paradigms of the Morris water maze test
• ED50 of morphine in wild-type is 3.67 mg/kg and 419.9 mg/kg in homozygotes; the drug has no analgesic effect in mutants

homeostasis/metabolism
• a dose of morphine (400 mg/kg) that is lethal to wild-type mice did not cause death of any mutant animals; the LD50 of morphine in homozygotes is much higher than 800 mg/kg
• homozygotes die within 2 hours at doses of 1600 mg/kg without typical morphine effects, suggesting reasons other than morphine toxicity




Genotype
MGI:3619218
hm2
Allelic
Composition
Oprm1tm1Loh/Oprm1tm1Loh
Genetic
Background
involves: 129P2/OlaHsd * BALB/c * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Loh mutation (0 available); any Oprm1 mutation (53 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• in slices from the dentate gyrus of mutants, only a small and short-lasting potentiaton of the population spike and the fEPSP, compared with wild-type mice
• application of a mu-opioid receptor antagonist decreased, LTP is depressed in the dentate gyrus of wild-type mice, but there is no effect in mutants




Genotype
MGI:3619220
hm3
Allelic
Composition
Oprm1tm1Loh/Oprm1tm1Loh
Genetic
Background
involves: 129P2/OlaHsd * BALB/cJ * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Loh mutation (0 available); any Oprm1 mutation (53 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
nervous system
• female mutants show ethanol-induced FOS reactivity in the GP and VP that is not seen in wild-type; FOS reactivity is seen in wild-type in the LSV, SCh, LGN and DGN but not in mutants in response to ethanol




Genotype
MGI:3625887
hm4
Allelic
Composition
Oprm1tm1Loh/Oprm1tm1Loh
Genetic
Background
involves: 129P2/OlaHsd * C57BL/6 * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Loh mutation (0 available); any Oprm1 mutation (53 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
homeostasis/metabolism
• oral administration of metformin does not affect plasma glucose in Oprm1-deficient diabetic mice 8-10 weeks of age but does lower glucose levels by ~21% in wild-type diabetic mice; in null mice and wild-type mice, beta-endorphin is elevated in the plasma with metformin treatment




Genotype
MGI:3625879
ht5
Allelic
Composition
Oprm1tm1Loh/Oprm1+
Genetic
Background
involves: 129P2/OlaHsd
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Loh mutation (0 available); any Oprm1 mutation (53 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• the LD50 of morphine in heterozygotes is 800 mg/kg, compared to 400 mg/kg for wild-type

behavior/neurological
• ED50 of morphine in wild-type is 3.67 mg/kg and 4.49 mg/kg in heterozygotes

homeostasis/metabolism
• the LD50 of morphine in heterozygotes is 800 mg/kg, compared to 400 mg/kg for wild-type





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last database update
05/07/2024
MGI 6.23
The Jackson Laboratory