Phenotypes Associated with This Genotype

Genotype
MGI:5439173

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

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

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