Phenotypes Associated with This Genotype

Genotype
MGI:5440955

• Allelic Composition: Itga7^tm1Burk/Itga7^tm1Burk; Sspn^tm1Kcam/Sspn^tm1Kcam
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

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

mortality/aging

premature death ( J:187752 )

• 10% of mutants do not survive past 4 weeks of age and by 8 months of age, viability it reduced to 50%

growth/size/body

decreased body weight ( J:187752 )

• reduced body weight compared to wild-type and Sspn single homozygotes

muscle

abnormal quadriceps morphology ( J:187752 )

• quadriceps muscles show severely diminished levels of laminin and sarcolemma damage

decreased quadriceps weight ( J:187752 )

• quadriceps muscle weights less than in either single homozygote

abnormal sarcolemma morphology ( J:187752 )

• quadriceps muscles at 4.5 months of age exhibit sarcolemma damage as indicated by Evan's blue dye accumulation

centrally nucleated skeletal muscle fibers ( J:187752 )

• mutants exhibit myopathy at 4.5 months of age, with centrally placed nuclei in skeletal muscles indicating muscle regeneration

abnormal diaphragm morphology ( J:187752 )

• mutants exhibit a greater increase in interstitial connective tissue between myofibers of the diaphragm compared to Itga7 single homozygotes

• mutants exhibit an increase in collagen deposition in the diaphragm and widespread fibrosis and adiposity at 4.5 months of age

abnormal skeletal muscle fiber type ratio ( J:187752 )

• diaphragms and quadriceps muscles exhibit greater numbers of small myofibers (more than 2-fold increase) and fewer larger fibers

decreased skeletal muscle mass ( J:187752 )

• reduced wet muscle mass compared to wild-type and Sspn single homozygotes

skeletal muscle atrophy ( J:187752 )

skeletal muscle fibrosis ( J:187752 )

• widespread fibrosis and adiposity in the diaphragm at 4.5 months of age and by 9 months of age, diaphragms show significant fibrotic collagen deposition and fat replacement

abnormal muscle physiology ( J:187752 )

• diaphragms exhibit a 51% reduction in specific muscle force values compared with wild-type

enhanced skeletal muscle regeneration ( J:187752 )

• increase in myofiber regeneration at 4.5 months of age, with a 16-fold increase in regeneration in the diaphragm

myopathy ( J:187752 )

• mutants exhibit myopathy at 4.5 months of age

homeostasis/metabolism

increased susceptibility to injury ( J:187752 )

• diaphragms exhibit increased susceptibility to eccentric contraction-induced damage as measured by the percent drop in force

skeleton

kyphosis ( J:187752 )

• severe kyphosis at 4.5 months of age as evidenced by the steep slope of the spine behind the shoulder blades, which is exacerbated at 6 months of age

limbs/digits/tail

abnormal quadriceps morphology ( J:187752 )

• quadriceps muscles show severely diminished levels of laminin and sarcolemma damage

decreased quadriceps weight ( J:187752 )

• quadriceps muscle weights less than in either single homozygote

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Duchenne muscular dystrophy		DOID:11723	OMIM:310200	J:187752