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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID 		Tg(Th-Oprm1)4Jtw
transgene insertion 4, John T Williams
MGI:4354389
Summary 3 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
cx1
 		Arrb2tm1Rjl/Arrb2tm1Rjl
Oprm1tm1Jep/Oprm1tm1Jep
Tg(Th-Oprm1)4Jtw/0 		involves: 129S/SvEv * 129X1/SvJ * C57BL/6 * DBA/2 MGI:4355146
cx2
 		Oprm1tm1Jep/Oprm1tm1Jep
Tg(Th-Oprm1)4Jtw/0 		involves: 129S/SvEv * C57BL/6 * DBA/2 MGI:4355145
tg3
 		Tg(Th-Oprm1)4Jtw/0 involves: C57BL/6 * DBA/2 MGI:4355144


Genotype
MGI:4355146
cx1
Allelic
Composition		 Arrb2tm1Rjl/Arrb2tm1Rjl
Oprm1tm1Jep/Oprm1tm1Jep
Tg(Th-Oprm1)4Jtw/0
Genetic
Background		 involves: 129S/SvEv * 129X1/SvJ * C57BL/6 * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Arrb2tm1Rjl mutation (2 available); any Arrb2 mutation (27 available)
Oprm1tm1Jep mutation (0 available); any Oprm1 mutation (55 available)
Tg(Th-Oprm1)4Jtw mutation (1 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
nervous system phenotype ( J:151536 )
N
• desensitization and internalization of opioid receptors after met-enkephalin treatment is similar to that in controls




Genotype
MGI:4355145
cx2
Allelic
Composition		 Oprm1tm1Jep/Oprm1tm1Jep
Tg(Th-Oprm1)4Jtw/0
Genetic
Background		 involves: 129S/SvEv * C57BL/6 * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Oprm1tm1Jep mutation (0 available); any Oprm1 mutation (55 available)
Tg(Th-Oprm1)4Jtw mutation (1 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
nervous system phenotype ( J:151536 )
N
• maximum hyperpolarization of neurons induced by met-enkephalin (ME) is similar to that seen in wild-type and transgenic wild-type opioid receptor mutant animals; the EC50 for ME is 50% greater than the transgene-only mutants
• desensitization by ME and recovery of desensitization of receptors is similar to wild-type and transgene-only controls
• desensitization and internalization of the mu-opioid receptor (MOR) in response to various MOR agonists is not different in mutants and controls




Genotype
MGI:4355144
tg3
Allelic
Composition		 Tg(Th-Oprm1)4Jtw/0
Genetic
Background		 involves: C57BL/6 * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tg(Th-Oprm1)4Jtw mutation (1 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
nervous system phenotype ( J:151536 )
N
• activation of the mu-opioid receptor (MOR) by met-enkephalin (ME) induces a hyperpolarization which desensitizes acutely to the same extent as the endogenous receptor in wild-type mice; a 7-fold decrease in the EC50 for ME is observed with the increased receptor expression seen in mutants




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Send questions and comments to User Support. 		last database update
09/30/2025
MGI 6.24 		The Jackson Laboratory