Phenotypes Associated with This Genotype

Genotype
MGI:6108871

• Allelic Composition: Tg(Myh7-Pln)2Egk/?
• Genetic Background: involves: FVB/N

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

muscle

abnormal soleus morphology ( J:127873 )

• soleus exhibits smaller muscle size, mass, and cross-sectional area

abnormal skeletal muscle fiber type ratio ( J:127873 )

• percentage of slow type I fibers is 25% higher in soleus muscle than in wild-type mice

impaired skeletal muscle contractility ( J:127873 )

• maximal twitch rate of contraction (+dF/dt) is reduced by 40% and the maximal twitch rate of relaxation (-dF/dt) is decreased by 45%, which are associated with a 2-fold prolongation of the contraction time and half-relaxation time

• beta-adrenergic stimulation of soleus with isoproterenol partially reverses the depressed contraction time and completely reverses the half-relaxation time

• soleus shows altered isometric twitch contractions, with the force developed by soleus reduced

• however, after normalization to the cross-sectional area of the muscle, the developed force is similar to controls

impaired muscle relaxation ( J:127873 )

• maximal twitch rate of contraction (+dF/dt) is reduced by 40% and the maximal twitch rate of relaxation (-dF/dt) is decreased by 45%, which are associated with a 2-fold prolongation of the contraction time and half-relaxation time

• beta-adrenergic stimulation of soleus with isoproterenol partially reverses the depressed contraction time and completely reverses the half-relaxation time

limbs/digits/tail

abnormal soleus morphology ( J:127873 )

• soleus exhibits smaller muscle size, mass, and cross-sectional area