All Phenotypes Tnnt2<+> MGI Mouse

Phenotypes associated with this allele

Jump to	Allelic Composition	Genetic Background	Genotype ID
ht1	Tnnt2^tm2.1Feah/Tnnt2⁺	involves: 129S6/SvEvTac * FVB/N	MGI:5910772
ht2	Tnnt2^tm1Mmto/Tnnt2⁺	involves: 129S/SvEv	MGI:3821723
ht3	Tnnt2^tm2Mmto/Tnnt2⁺	involves: 129S/SvEv * C57BL/6	MGI:3804499
cx4	Pln^tm1Egk/Pln^tm1Egk Tnnt2^tm2.1Feah/Tnnt2⁺	involves: 129S2/SvPas * 129S6/SvEvTac * FVB/N	MGI:5910773
cx5	Tg(Myh6-Tnnt2*)1Feah/0 Tnnt2^tm1Feah/Tnnt2⁺	involves: 129S/SvEv * 129S6/SvEvTac * FVB/N	MGI:3805039

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

mortality/aging

decreased survivor rate ( J:243725 )

• mice exhibit poor survival, with females showing better survival rates than males

premature death ( J:243725 )

• mice exhibit poor survival, with females showing better survival rates than males

cardiovascular system

dilated heart left ventricle ( J:243725 )

• increase in left ventricular end diastolic diameter indicating left ventricle dilation

abnormal cardiovascular system physiology ( J:243725 )

• the Hill coefficient is decreased in hearts, implying decreased cooperativity in muscle force generation

• 54% and 20% increases, respectively, in peak systolic and end diastolic intracellular calcium concentrations in 8 week old hearts

• hearts show a prolonged systolic rise and diastolic fall in calcium concentrations

dilated cardiomyopathy ( J:243725 )

• dilated cardiomyopathy is evident at 6 weeks of age and persists at 12 and 30 weeks of age

• however, no myofibrillar disarray, fibrosis or apoptosis is seen in 16 week old mice

decreased cardiac muscle contractility ( J:243725 )

• decrease in fractional shorting indicating reduced systolic function

abnormal heart echocardiography feature ( J:243725 )

• echocardiography shows increases in left ventricular end diastolic diameter and left ventricular end systolic diameter and decreases in fractional shorting in both males and females at 6, 12, and 30 weeks of age

decreased heart rate ( J:243725 )

• hearts exhibit a slower intrinsic sinus rhythm heart rate

• hearts exhibit lower peak heart rates in response to beta-adrenergic stimulation with isoproterenol and exposure to higher isoproterenol levels leads to sustained dysrhythmias

ventricular tachycardia ( J:243725 )

• 2 of 4 mice exhibit nonsustainable polymorphic ventricular tachyarrhythmia on aggressive programmed ventricular stimulation

abnormal myocardial fiber physiology ( J:243725 )

• skinned fibers from hearts show reduced myofilament calcium sensitivity, without any changes in maximally activated force or length-dependent changes in calcium sensitivity

muscle

dilated cardiomyopathy ( J:243725 )

• dilated cardiomyopathy is evident at 6 weeks of age and persists at 12 and 30 weeks of age

• however, no myofibrillar disarray, fibrosis or apoptosis is seen in 16 week old mice

decreased cardiac muscle contractility ( J:243725 )

• decrease in fractional shorting indicating reduced systolic function

nervous system

abnormal action potential ( J:243725 )

• action potential durations are shorter in hearts

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
dilated cardiomyopathy 1D		DOID:0110426	OMIM:601494	J:243725

Allelic Composition	Tnnt2^tm1Mmto/Tnnt2⁺
Genetic Background	involves: 129S/SvEv

Find Mice

Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tnnt2^tm1Mmto mutation (1 available); any Tnnt2 mutation (50 available)

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

normal phenotype

no abnormal phenotype detected ( J:141967 )

• despite most causative mutations in TNNT2 resulting in cardiomyopathy in humans being dominant, heterozygous mice are viable with normal heart structure and function

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
NOT	dilated cardiomyopathy 1D	DOID:0110426	OMIM:601494	J:141967

Allelic Composition	Tnnt2^tm2Mmto/Tnnt2⁺
Genetic Background	involves: 129S/SvEv * C57BL/6

Find Mice

Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tnnt2^tm2Mmto mutation (0 available); any Tnnt2 mutation (50 available)

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

mortality/aging

premature death ( J:137784 )

• high incidence of sudden death in mice particularly between 1 and 3 months of age

• mice die after developing repetitive Torsade des Pointes which degenerates into ventricular defibrillation

• treatment with pimobendan, a Ca²⁺ sensitizer increases life span

cardiovascular system

enlarged heart ( J:137784 )

• increase in size is greater in homozygotes compared to heterozygotes

• treatment with pimobendan, a Ca²⁺ sensitizer decreases heart size

abnormal heart left ventricle morphology ( J:137784 )

• increase in left ventricular end-diastolic dimension

• however, no significant differences in wall thickness are detected

cardiac interstitial fibrosis ( J:137784 )

abnormal cardiovascular system physiology ( J:137784 )

• markers of heart failure are significantly increased at 3 and 5 but not at 2 months of age

decreased heart left ventricle muscle contractility ( J:137784 )

• significant reduction in left ventricular ejection fraction

decreased left ventricle systolic pressure ( J:137784 )

• lower left ventricular end-systolic pressure after administration of isoproterenol

• but, no significant difference in blood pressure of heart rate

prolonged QT interval ( J:137784 )

• electrophysiological abnormalities with long QT

abnormal myocardial fiber physiology ( J:137784 )

• decrease in Ca²⁺ sensitivity of force generation with a reduced pCa value at half-maximal force generation

• faster peak rates of increase and decrease in cytoplasmic Ca²⁺ in intact fibers compared to wild-type controls

• significant increase in cardiomyocyte apoptosis

• differences are larger in homozygotes compared to heterozygotes

• however, maximum force-generating capabilities and Hill coefficient values are not different from controls and intact fibers show no significant decrease in maximum isometric force per cross-sectional area

muscle

decreased heart left ventricle muscle contractility ( J:137784 )

• significant reduction in left ventricular ejection fraction

growth/size/body

enlarged heart ( J:137784 )

• increase in size is greater in homozygotes compared to heterozygotes

• treatment with pimobendan, a Ca²⁺ sensitizer decreases heart size

cellular

cardiac interstitial fibrosis ( J:137784 )

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
dilated cardiomyopathy 1D		DOID:0110426	OMIM:601494	J:137784

Allelic Composition	Pln^tm1Egk/Pln^tm1Egk Tnnt2^tm2.1Feah/Tnnt2⁺
Genetic Background	involves: 129S2/SvPas * 129S6/SvEvTac * FVB/N

Find Mice

Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Pln^tm1Egk mutation (7 available); any Pln mutation (16 available)
Tnnt2^tm2.1Feah mutation (0 available); any Tnnt2 mutation (50 available)

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

cardiovascular system

dilated heart left ventricle ( J:243725 )

• mice exhibit left ventricular dilatation

dilated cardiomyopathy ( J:243725 )

• dilated cardiomyopathy is similar to that seen in single Tnnt2 heterozygotes

decreased cardiac muscle contractility ( J:243725 )

• mice exhibit decreased fractional shortening

muscle

dilated cardiomyopathy ( J:243725 )

• dilated cardiomyopathy is similar to that seen in single Tnnt2 heterozygotes

decreased cardiac muscle contractility ( J:243725 )

• mice exhibit decreased fractional shortening

Allelic Composition	Tg(Myh6-Tnnt2*)1Feah/0 Tnnt2^tm1Feah/Tnnt2⁺
Genetic Background	involves: 129S/SvEv * 129S6/SvEvTac * FVB/N

Find Mice

Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tg(Myh6-Tnnt2*)1Feah mutation (0 available)
Tnnt2^tm1Feah mutation (0 available); any Tnnt2 mutation (50 available)

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

cardiovascular system

dilated heart ( J:137964 )

• massive

dilated cardiomyopathy ( J:137964 )

• mice exhibit severe dilated cardiomyopathy

• left ventricular end diastolic diameter is increased compared to in heterozygous mice with a wild-type transgene

decreased cardiac muscle contractility ( J:137964 )

increased heart rate ( J:137964 )

• non-sustained tachycardia was induced in 2 of 5 mice compared to only 1 of 10 wild-type mice

abnormal heart electrocardiography waveform feature ( J:137964 )

prolonged HV interval ( J:137964 )

prolonged QRS complex duration ( J:137964 )

prolonged QT interval ( J:137964 )

abnormal myocardial fiber physiology ( J:137964 )

• mice exhibit myofiber calcium desensitization

congestive heart failure ( J:137964 )

• evident by molecular markers

muscle

dilated cardiomyopathy ( J:137964 )

• mice exhibit severe dilated cardiomyopathy

• left ventricular end diastolic diameter is increased compared to in heterozygous mice with a wild-type transgene

decreased cardiac muscle contractility ( J:137964 )

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