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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Nrg1tm3Cbm
targeted mutation 3, Carmen Birchmeier
MGI:2447761
Summary 3 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
cn1
Nrg1tm1Cbm/Nrg1tm3Cbm
Isl2tm1Arbr/Isl2+
involves: 129P2/OlaHsd * 129S7/SvEvBrd * C57BL/6J MGI:3723120
cn2
Nrg1tm1Cbm/Nrg1tm3Cbm
Isl1tm1(cre)Tmj/Isl1+
involves: 129P2/OlaHsd * 129X1/SvJ MGI:2653523
cn3
Nrg1tm3Cbm/Nrg1tm3Cbm
Tg(CAG-cre/Esr1*)5Amc/0
involves: 129P2/OlaHsd * C57BL/6 * CBA MGI:5524264


Genotype
MGI:3723120
cn1
Allelic
Composition
Nrg1tm1Cbm/Nrg1tm3Cbm
Isl2tm1Arbr/Isl2+
Genetic
Background
involves: 129P2/OlaHsd * 129S7/SvEvBrd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Isl2tm1Arbr mutation (1 available); any Isl2 mutation (28 available)
Nrg1tm1Cbm mutation (0 available); any Nrg1 mutation (54 available)
Nrg1tm3Cbm mutation (0 available); any Nrg1 mutation (54 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• ~90% of mice die at birth, with phenotype similar to Nrg1tm1Cbm homozygous embryos

nervous system
• Schwann cells are absent from intramuscular motor axons between E13.5-E16.5
• motor neurons are defasciculated and disorganized
• in developing muscle, motor axons largely retract by birth; by E18.5, motor axons and terminals are absent
• at diaphragm synapses, band of acetylcholine receptors (AChRs) is wider (17.5% of muscle length) than in wild-type muscle (7% of muscle length)




Genotype
MGI:2653523
cn2
Allelic
Composition
Nrg1tm1Cbm/Nrg1tm3Cbm
Isl1tm1(cre)Tmj/Isl1+
Genetic
Background
involves: 129P2/OlaHsd * 129X1/SvJ
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Isl1tm1(cre)Tmj mutation (0 available); any Isl1 mutation (36 available)
Nrg1tm1Cbm mutation (0 available); any Nrg1 mutation (54 available)
Nrg1tm3Cbm mutation (0 available); any Nrg1 mutation (54 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
muscle
• mutants exhibit a defect in muscle spindle differentiation in the dorsal root ganglion and motor neurons

nervous system
• mutants exhibit a defect in muscle spindle differentiation in the dorsal root ganglion and motor neurons
• selective absence of Schwann cells at E16.5 in adductor and gracilis muscles but not in other muscles
• parvalbumin+ proprioceptive terminals at muscle spindles remain primitive and unbranched at E18.5
• parvalbumin+ proprioceptive afferents are present in E16.5 hindlimb muscles and initiate contact with individual myofibers, but they do not develop annulospiral branches around the myofibers
• however, survival and initial differentiation of proprioceptive afferent sensory neurons is not impaired




Genotype
MGI:5524264
cn3
Allelic
Composition
Nrg1tm3Cbm/Nrg1tm3Cbm
Tg(CAG-cre/Esr1*)5Amc/0
Genetic
Background
involves: 129P2/OlaHsd * C57BL/6 * CBA
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Nrg1tm3Cbm mutation (0 available); any Nrg1 mutation (54 available)
Tg(CAG-cre/Esr1*)5Amc mutation (10 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
muscle
• small diameter with degeneration of the outer capsule in tamoxifen-treated mice
• however, innervation is normal
• in tamoxifen-treated mice

behavior/neurological
• tamoxifen-treated mice hang on to an inverted grid 3 to 4 times less than controls mice
• strongly impaired in a beam-walking test

nervous system
• small diameter with degeneration of the outer capsule in tamoxifen-treated mice
• however, innervation is normal
• in tamoxifen-treated mice





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last database update
12/10/2024
MGI 6.24
The Jackson Laboratory