Phenotypes Associated with This Genotype

Genotype
MGI:6401817

• Allelic Composition: Col6a1^tm1Sngi/Col6a1^tm1Sngi
• Genetic Background: B6.Cg-Col6a1^tm1Sngi

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

growth/size/body

decreased body size ( J:278926 )

decreased body weight ( J:278926 )

• smaller body weight throughout life

behavior/neurological

decreased grip strength ( J:278926 )

• grip test shows limb muscle weakness after 14 weeks of age, but weakness is not progressive

abnormal locomotor behavior ( J:278926 )

• voluntary wheel running locomotion is reduced

muscle

abnormal muscle development ( J:278926 )

• membrane indentation of myofibers is fewer and the lag in increment of myofibers starts at day 15, indicating a defect in muscle growth

• the number of mesenchymal progenitor cells is increased in skeletal muscles, even at 30 weeks of age

abnormal skeletal muscle morphology ( J:278926 )

• the number of mesenchymal progenitor cells is increased in skeletal muscles, even at 30 weeks of age

• mesenchymal progenitor cells are elongated and detached from the basement membrane instead of being round or ovoid shape and juxtaposed to the basement membrane

abnormal skeletal muscle fiber morphology ( J:278926 )

• myofibers smaller than 15 um are increased

• the number of myonuclei per myofiber is increased

• however, total number of myonuclei in tibialis anterior muscle is normal

increased variability of skeletal muscle fiber size ( J:278926 )

decreased skeletal muscle fiber number ( J:278926 )

• reduction in the total number of myofibers after 3 weeks of age but not at P1

• however, no differences in individual myofiber diameter are seen

decreased skeletal muscle mass ( J:278926 )

decreased skeletal muscle size ( J:278926 )

• decrease in muscle size and cross-sectional areas

• muscles are smaller at 30 weeks of age but have no dystrophic changes, necrosis or centrally-placed nuclei

skeletal muscle endomysial fibrosis ( J:278926 )

• endomysial fibrosis is notable after 20 weeks of age

impaired skeletal muscle contractility ( J:278926 )

• tibialis anterior muscle and gastrocnemius muscle contractile forces, including twitch and tetanic contractions, are lower

• specific forces are reduced in twitch contraction

muscle weakness ( J:278926 )

• mice show non-progressive mild muscle weakness

homeostasis/metabolism

decreased circulating insulin-like growth factor I level ( J:278926 )

• serum IGF-1 level is 80% that of controls at P15

impaired glucose tolerance ( J:278926 )

• impaired glucose tolerance without insulin resistance

abnormal response to injury ( J:278926 )

• following cardiotoxin injections to muscles to induce necrosis/regeneration, muscles how marked fiber size variation and endomysial fibrosis and an increase in muscle-retained mesenchymal progenitor cells indicating persistence of muscle regeneration

• however, no delay or defects in muscle regeneration process are seen following cardiotoxin injection

skeleton

skeleton phenotype ( J:278926 )

N • no apparent abnormalities in bone, joint, or skin are seen

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Ullrich congenital muscular dystrophy		DOID:0050558		J:278926