Phenotypes Associated with This Genotype

Genotype
MGI:5697652

• Allelic Composition: Dmd^mdx/Dmd^mdx
• Genetic Background: D2.B10-Dmd^mdx/J

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

muscle

cardiac muscle degeneration ( J:226314 )

decreased cardiac muscle contractility ( J:226314 )

• lower ejection fraction and shortening fraction than DBA/2J controls at 28 and 52 weeks of age

• Background Sensitivity: ejection fraction and shortening fraction is lower than in Dmd^mdx mice on C57BL/10ScSn background at 28 weeks of age

cardiomyopathy ( J:226314 )

• cardiomyopathy is observed at 7 weeks of age in mice on the DBA/2J background

• Background Sensitivity: cardiomyopathy is observed at 28 weeks of age in Dmd^mdx mice on the C57BL/10ScSn background

myositis ( J:226314 )

• forelimb and hindlimb inflammation (as measured by cathepsin activity) is observed at 7 weeks of age

• inflammation in the forelimb is still observed at 52 weeks of age

• inflammation and mononuclear cell infiltration is observed in the quadriceps beginning at 7 weeks of age

• Background Sensitivity: forelimb inflammation at 52 weeks is not observed in mice on on the C57BL/10ScSn background

abnormal skeletal muscle fiber morphology ( J:226314 )

♂ • high incidence of primary and complex branching in myofibers from extensor digitorum longus (EDL) in 12 week old male mice

decreased skeletal muscle fiber size ( J:226314 )

• increase in average number of nuclei per myofiber and decreased F-actin content from EDL at 12 weeks of age

• decrease in myonuclear domain from EDL at 12 weeks of age

• increased number of small fibers and smaller number of normal sized fibers

decreased skeletal muscle fiber diameter ( J:226314 )

• tibialis anterior muscle fibers are reduced in diameter (375 m²) as compared to DBA/2J mice (375-750 m²)

centrally nucleated skeletal muscle fibers ( J:226314 )

• mice exhibit an increased number of centrally nucleated fibers

• myonuclei are predominantly located in juxtasarcolemmal position on the DBA/2J background

• Background Sensitivity: increase is less on the DBA/2J background than on the C57BL/10ScSn background

• Background Sensitivity: myonuclei are predominantly centrally located on the C57BL/10ScSn background

decreased skeletal muscle mass ( J:226314 )

• loss of muscle mass in gastrocnemius, tibialis anterior and quadriceps as compared to controls

• reduced muscle mass in extensor digitorum longus (EDL) as compared to DBA/2J at 28 and 52 weeks of age

• Background Sensitivity: reduced muscle mass in EDL as compared to Dmd^mdx mice on C57BL/10ScSn background at 7, 28 and 52 weeks of age

skeletal muscle atrophy ( J:226314 )

• muscle atrophy is observed in mice on the DBA/2J background

• Background Sensitivity: however, muscle hypertrophy is observed in Dmd^mdx mice on the C57BL/10ScSn background

skeletal muscle fiber atrophy ( J:226314 )

skeletal muscle degeneration ( J:226314 )

• lesions that are observed in quadriceps and diaphragm exhibit muscle degeneration, regeneration and mononuclear infiltrating cells at 7 weeks of age

• increased uptake of Evans blue dye, a measure of muscle damage, as compared to DBA/2J controls at 8 weeks of age

• Background Sensitivity: uptake is higher than in Dmd^mdx mice on the C57BL/10ScSn background

calcified muscle ( J:226314 )

• calcifications in quadriceps, heart, diaphragm and epicardium of heart at 7 weeks of age

• Background Sensitivity: Dmd^mdx mice on the C57BL/10ScSn background did not exhibit calcifications until 52 weeks of age

dystrophic muscle ( J:226314 )

• Background Sensitivity: onset of muscular dystrophy is later and less severe in Dmd^mdx mice on on the C57BL/10ScSn background

impaired skeletal muscle contractility ( J:226314 )

• decrease in specific and maximal force generation in EDL at 7, 28 and 52 weeks as compared to DBA/2J controls

• Background Sensitivity: decrease in specific and maximal force generation in EDL at 7 and 28 weeks as compared to Dmd^mdx mice on C57BL/10ScSn background

abnormal skeletal muscle regeneration ( J:226314 )

• lesions that are observed in quadriceps and diaphragm exhibit muscle degeneration, regeneration and mononuclear infiltrating cells at 7 weeks of age

cardiovascular system

cardiac muscle degeneration ( J:226314 )

dystrophic cardiac calcinosis ( J:226314 )

• calcifications in quadriceps, heart, diaphragm and epicardium of heart at 7 weeks of age

• Background Sensitivity: Dmd^mdx mice on the C57BL/10ScSn background did not exhibit calcifications until 52 weeks of age

decreased cardiac output ( J:226314 )

decreased cardiac stroke volume ( J:226314 )

• decreased left ventricular (stroke) volume

decreased cardiac muscle contractility ( J:226314 )

• lower ejection fraction and shortening fraction than DBA/2J controls at 28 and 52 weeks of age

• Background Sensitivity: ejection fraction and shortening fraction is lower than in Dmd^mdx mice on C57BL/10ScSn background at 28 weeks of age

cardiomyopathy ( J:226314 )

• cardiomyopathy is observed at 7 weeks of age in mice on the DBA/2J background

• Background Sensitivity: cardiomyopathy is observed at 28 weeks of age in Dmd^mdx mice on the C57BL/10ScSn background

heart inflammation ( J:226314 )

• inflammation within cardiac tissue is observed by 7 weeks of age

• Background Sensitivity: inflammation is not observed in in Dmd^mdx mice on the C57BL/10ScSn background

growth/size/body

decreased body size ( J:226314 )

• mice have reduced body mass as compared to DBA/2J controls

• Background Sensitivity: Dmd^mdx mice on the DBA/2J background have reduced body mass as compared to mice on the C57BL/10ScSn background at 28 weeks

homeostasis/metabolism

increased circulating creatine kinase level ( J:226314 )

• elevated levels of serum creatine kinase as compared to DBA/2J controls at 24 and 28 weeks

• Background Sensitivity: levels are lower at 24 weeks as compared to Dmd^mdx mice on the C57BL/10ScSn background

increased creatine kinase activity ( J:226314 )

• increased creatine kinase activity as compared to DBA/2J controls at 24 and 28 weeks

• Background Sensitivity: activity is lower at 24 weeks as compared to Dmd^mdx mice on the C57BL/10ScSn background

immune system

heart inflammation ( J:226314 )

• inflammation within cardiac tissue is observed by 7 weeks of age

• Background Sensitivity: inflammation is not observed in in Dmd^mdx mice on the C57BL/10ScSn background

myositis ( J:226314 )

• forelimb and hindlimb inflammation (as measured by cathepsin activity) is observed at 7 weeks of age

• inflammation in the forelimb is still observed at 52 weeks of age

• inflammation and mononuclear cell infiltration is observed in the quadriceps beginning at 7 weeks of age

• Background Sensitivity: forelimb inflammation at 52 weeks is not observed in mice on on the C57BL/10ScSn background

behavior/neurological

decreased grip strength ( J:226314 )

• reduced forelimb grip strength at 12 weeks and 24 weeks as compared to controls

• reduced hindlimb grip strength at 24 weeks, as compared to controls, however, gap closes by 52 weeks

• Background Sensitivity: forelimb grip strength at 28 weeks is higher than grip strength in Dmd^mdx mice on C57BL/10ScSn background, but still less than controls

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Duchenne muscular dystrophy		DOID:11723	OMIM:310200	J:226314