Phenotypes Associated with This Genotype

Genotype
MGI:5697946

• Allelic Composition: Tnnt1^tm1.2Jin/Tnnt1^tm1.2Jin
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

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

muscle

abnormal muscle fiber morphology ( J:219907 )

• hypertrophic growth of type II fast fibers and atrophy of type I slow fibers in soleus muscle

decreased skeletal muscle fiber size ( J:219907 )

• soleus muscle type I slow fibers are small-sized

decreased skeletal muscle fiber diameter ( J:219907 )

• approximate 40% decrease in the cross-sectional area of type I slow fibers

skeletal muscle fiber atrophy ( J:219907 )

• atrophy of type I slow fibers in soleus muscle

increased skeletal muscle fiber diameter ( J:219907 )

• the cross-sectional area of fast type II muscle fibers from soleus muscles is increased by about 76%

centrally nucleated skeletal muscle fibers ( J:219907 )

• soleus muscle type I slow fibers are characterized by centrally nucleated fibers

abnormal skeletal muscle fiber type ratio ( J:219907 )

• loss of type I slow fibers in the adult soleus and diaphragm muscles resulting in a switch to nearly pure fast fiber muscle

abnormal skeletal muscle size ( J:219907 )

• in vivo length of soleus muscles is shorter

abnormal muscle physiology ( J:219907 )

• twitch force normalized to cross-sectional area is decreased by about 25% in soleus muscle

• the optimal length of soleus muscles at which maximum twitch force is achieved in ex vivo contractility experiments is shorter

• soleus muscle shows decreased fatigue tolerance with impaired recovery

abnormal muscle contractility ( J:219907 )

• the time for maximum force development during twitch contraction is shorter in soleus muscles, however contractile velocity is normal

• force-frequency analysis shows that at low stimulation frequency of 40 Hz, force production is soleus muscles is lower than in controls

abnormal muscle relaxation ( J:219907 )

• relaxation velocity of twitch and tetanic contractions are accelerated in soleus muscles

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
nemaline myopathy 5A		DOID:0110936	OMIM:605355	J:219907