Phenotypes associated with this allele

• Allele Symbol: Barx2^tm1Rsd
• Allele Name: targeted mutation 1, Michael G Rosenfeld
• Allele ID: MGI:3574438
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Barx2^tm1Rsd/Barx2^tm1Rsd	involves: 129/Sv * C57BL/6	MGI:3574603
cx2	Barx2^tm1Rsd/Barx2^tm1Rsd Dmd^mdx/Y	involves: 129 * C57BL/6 * C57BL/10ScSn	MGI:5439173
cx3	Barx2^tm1Rsd/Barx2^tm1Rsd Dmd^mdx/Dmd^mdx	involves: 129 * C57BL/6 * C57BL/10ScSn	MGI:5439179

Genotype
MGI:3574603

hm1

• Allelic Composition: Barx2^tm1Rsd/Barx2^tm1Rsd
• Genetic Background: involves: 129/Sv * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

Barx2^tm1Rsd/Barx2^tm1Rsd mice display open eyelids at birth, abnormal hair follicle remodeling and short whiskers and hair

pigmentation

abnormal skin pigmentation ( J:96883 )

• a delay in the anterior to posterior clearing of pigments that occurs during the hair cycle is seen

endocrine/exocrine glands

enlarged sebaceous gland ( J:96883 )

• seen during the final stages of the protracted catagen

vision/eye

eyelids open at birth ( J:96883 )

• in about 50% of homozygotes

integument

enlarged sebaceous gland ( J:96883 )

• seen during the final stages of the protracted catagen

alopecia ( J:187799 )

• mild alopecia is seen by 15-18 months of age

short hair ( J:96883 )

• hair length is initially normal but becomes significantly shorter (about 15-20% shorter compared to wild-type) by 6 months of age

disheveled coat ( J:96883 , J:187799 )

• at about 2 weeks of age a transient disheveled appearance of the coat is seen (J:96883)

short vibrissae ( J:96883 )

abnormal hair cycle ( J:96883 )

• the final stages of catagen are protracted and homozygotes do not reach telogen until P22-P23 compared to P19 in wild-type mice

abnormal skin pigmentation ( J:96883 )

• a delay in the anterior to posterior clearing of pigments that occurs during the hair cycle is seen

behavior/neurological

abnormal motor capabilities/coordination/movement ( J:187799 )

• splayed limb-stance

abnormal gait ( J:187799 )

• waddling gait

growth/size/body

decreased body weight ( J:187799 )

• mutants show a 10% reduction in body weight at P4 and a 20-25% reduction at 4 weeks of age, however no difference in body weight is seen at birth

slow postnatal weight gain ( J:187799 )

• mutants show reduction in growth after birth, with growth delay most pronounced at around 4 weeks of age, when mutants are 20-25% smaller than heterozygotes or wild-type littermates

• however, mutants do not show any overt signs of feeding difficulties

muscle

abnormal muscle fiber morphology ( J:187799 )

• satellite-cell derived myoblasts from P4 muscles show altered morphology and reduced proliferation in culture; more myoblasts are rounded and show decreased spreading compared to wild-type cells

• analysis of differentiation markers indicates that satellite-cell derived myoblasts from P4 muscles show delayed differentiation

• myoblasts and myotubes exhibit poor adhesion to fibronectin

abnormal skeletal muscle morphology ( J:187799 )

• 15-18 month old mutants show musculoskeletal abnormalities

abnormal skeletal muscle fiber morphology ( J:187799 )

• muscles contain fewer large myofibers and a greater number of smaller myofibers compared to controls

• soleus muscles exhibit narrower myofibers, more rounded myofibers, and an increased distance between myofibers compared to wild-type

decreased skeletal muscle fiber diameter ( J:187799 )

• soleus and tibialis anterior muscles show narrower myofibers compared to wild-type

increased variability of skeletal muscle fiber size ( J:187799 )

• tibialis anterior muscles show greater variability in myofiber size and shape relative to wild-type

thin diaphragm muscle ( J:187799 )

• diaphragms of 6 month old mutants are thinner than in wild-type and this is associated with thinner myofibers

decreased skeletal muscle mass ( J:187799 )

• limb muscle mass is reduced

• muscles are reduced in disproportion to overall body mass and the mass of other organs

skeletal muscle fiber atrophy ( J:187799 )

• groups of angulated atrophic fibers are seen in soleus muscles

decreased skeletal muscle weight ( J:187799 )

• tibialis anterior and quadriceps muscles from 4 week old mutants weigh 20-30% less than in controls

• soleus muscle is reduced by almost 60%

skeletal muscle fibrosis ( J:187799 )

• mild fibrosis in the diaphragm at 6 months of age

impaired skeletal muscle regeneration ( J:187799 )

• mutants intramuscularly injected with cardiotoxin to induce muscle injury show impaired muscle regeneration compared to wild-type, with necrosis still evident 10 days after injection

skeleton

abnormal spine curvature ( J:187799 )

Genotype
MGI:5439173

cx2

• Allelic Composition: Barx2^tm1Rsd/Barx2^tm1Rsd; Dmd^mdx/Y
• Genetic Background: involves: 129 * C57BL/6 * C57BL/10ScSn

cellular

skeletal muscle fiber necrosis ( J:187799 )

♂

mortality/aging

postnatal lethality, incomplete penetrance ( J:187799 )

♂ • mutants are under-represented at weaning age

growth/size/body

decreased body size ( J:187799 )

♂ • mutants are about 30% smaller than single Dmd mutants at 4 weeks of age; organs are reduced proportionately

behavior/neurological

abnormal gait ( J:187799 )

♂ • mutants become progressively less ambulatory with a waddling gait

♂ • gait abnormalities appear earlier and are more severe than in single Barx2 mutants

decreased locomotor activity ( J:187799 )

♂ • mutants become progressively less ambulatory

muscle

skeletal muscle fiber necrosis ( J:187799 )

♂

increased variability of skeletal muscle fiber size ( J:187799 )

♂ • organization of tibialis anterior muscle is extremely aberrant with greater variability in myofiber size and fewer central nuclei releative to muscle from single Dmd mutants

♂ • soleus muscles show greater variability in myofiber size and shape compared to muscle from single Dmd mutants

decreased muscle weight ( J:187799 )

♂ • tibialis anterior muscle weighs on average 50% less than in single Dmd mutants, indicating muscle wasting

abnormal diaphragm morphology ( J:187799 )

♂ • at 12 months of age, diaphragms show a greater instance of focal myofiber necrosis and necrotic myofibers undergoing myophagocytosis and more fibrosis compared to single Dmd mutants

thin diaphragm muscle ( J:187799 )

♂ • diaphragm muscles at 6 months of age are much thinner than in single Dmd mutants and show more frequent rounded opaque fibers often with clear vacuoles, indicating hypercontracted atrophic fibers

skeletal muscle fibrosis ( J:187799 )

♂ • soleus muscles show more endomysial and perimysial fibrosis compared to muscle from single Dmd mutants

♂ • diaphragms show more fibrosis than single Dmd mutants

skeletal muscle endomysial fibrosis ( J:187799 )

♂ • in soleus muscles

impaired skeletal muscle regeneration ( J:187799 )

♂ • tibialis anterior muscle shows fewer central nuclei relative to muscle from single Dmd mutants, indicating reduction in repair of muscle damage

progressive muscle weakness ( J:187799 )

♂ • mutants become progressively weak

skeleton

kyphosis ( J:187799 )

♂ • mutants develop spine deformation resembling kyphosis by 6 months of age

♂ • spine deformation appears earlier and is more severe than in single Barx2 mutants

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Duchenne muscular dystrophy		DOID:11723	OMIM:310200	J:187799

Genotype
MGI:5439179

cx3

• Allelic Composition: Barx2^tm1Rsd/Barx2^tm1Rsd; Dmd^mdx/Dmd^mdx
• Genetic Background: involves: 129 * C57BL/6 * C57BL/10ScSn

cellular

skeletal muscle fiber necrosis ( J:187799 )

♀

mortality/aging

postnatal lethality, incomplete penetrance ( J:187799 )

♀ • mutants are under-represented at weaning age

growth/size/body

decreased body size ( J:187799 )

♀ • mutants are about 30% smaller than single Dmd mutants at 4 weeks of age; organs are reduced proportionately

behavior/neurological

abnormal gait ( J:187799 )

♀ • mutants become progressively less ambulatory with a waddling gait

♀ • gait abnormalities appear earlier and are more severe than in single Barx2 mutants

decreased locomotor activity ( J:187799 )

♀ • mutants become progressively less ambulatory

muscle

skeletal muscle fiber necrosis ( J:187799 )

♀

increased variability of skeletal muscle fiber size ( J:187799 )

♀ • organization of tibialis anterior muscle is extremely aberrant with greater variability in myofiber size and fewer central nuclei releative to muscle from single Dmd mutants

♀ • soleus muscles show greater variability in myofiber size and shape compared to muscle from single Dmd mutants

decreased muscle weight ( J:187799 )

♀ • tibialis anterior muscle weighs on average 50% less than in single Dmd mutants, indicating muscle wasting

abnormal diaphragm morphology ( J:187799 )

♀ • at 12 months of age, diaphragms show a greater instance of focal myofiber necrosis and necrotic myofibers undergoing myophagocytosis and more fibrosis compared to single Dmd mutants

thin diaphragm muscle ( J:187799 )

♀ • diaphragm muscles at 6 months of age are much thinner than in single Dmd mutants and show more frequent rounded opaque fibers often with clear vacuoles, indicating hypercontracted atrophic fibers

skeletal muscle fibrosis ( J:187799 )

♀ • soleus muscles show more endomysial and perimysial fibrosis compared to muscle from single Dmd mutants

♀ • diaphragms show more fibrosis than single Dmd mutants

skeletal muscle endomysial fibrosis ( J:187799 )

♀ • in soleus muscles

impaired skeletal muscle regeneration ( J:187799 )

♀ • tibialis anterior muscle shows fewer central nuclei relative to muscle from single Dmd mutants, indicating reduction in repair of muscle damage

progressive muscle weakness ( J:187799 )

♀ • mutants become progressively weak

skeleton

kyphosis ( J:187799 )

♀ • mutants develop spine deformation resembling kyphosis by 6 months of age

♀ • spine deformation appears earlier and is more severe than in single Barx2 mutants

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Duchenne muscular dystrophy		DOID:11723	OMIM:310200	J:187799