Phenotypes associated with this allele

• Allele Symbol: Myh6^tm1Rbns
• Allele Name: targeted mutation 1, Jeffrey Robbins
• Allele ID: MGI:3652543
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Myh6^tm1Rbns/Myh6^tm1Rbns	involves: 129P2/OlaHsd	MGI:3652797
ht2	Myh6^tm1Rbns/Myh6^+	involves: 129P2/OlaHsd	MGI:3652799

Genotype
MGI:3652797

hm1

• Allelic Composition: Myh6^tm1Rbns/Myh6^tm1Rbns
• Genetic Background: involves: 129P2/OlaHsd

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:36089 )

• homozygotes die in utero between E11-12.5 of gross heart defects

Genotype
MGI:3652799

ht2

• Allelic Composition: Myh6^tm1Rbns/Myh6⁺
• Genetic Background: involves: 129P2/OlaHsd

Fibrotic lesions in Myh6^tm1Rbns/Myh6⁺ hearts

cardiovascular system

abnormal myocardium layer morphology ( J:36089 )

abnormal myocardial fiber morphology ( J:36089 )

• the average length of myofibrils is ~50% that of control lengths; the A bands of myofibrils occupy the entire sarcomeric length and I bands cant't be detected; A band length is reduced by approximately 75% relative to controls

• mutant sarcomeres are only 79% as long as controls

• myofibrils display numerous areas where thin filaments are absent compared to controls which have regular hexameric arrays of thick and thin filaments

abnormal heart ventricle morphology ( J:36089 )

• some of the heterozygotes (3/8) appear to have hypertrophy of the ventricular walls associated with occlusion of the left ventricular chamber

cardiac fibrosis ( J:36089 )

• many hearts show multifocal areas of fibrosis, most commonly in the apex and left ventricular wall; fibrosis is also frequently seen in the right ventricle and interventricular septum

decreased cardiac muscle contractility ( J:36089 )

• mutants display increased time to peak pressure, indicative of reduced contractility

decreased left ventricle diastolic pressure ( J:36089 )

• mutant hearts have diastolic IVPs that are 9mm Hg higher than wild-type

decreased left ventricle systolic pressure ( J:36089 )

• mutant hearts have systolic IVPs that are 14mm Hg lower than wild-type

muscle

abnormal myocardium layer morphology ( J:36089 )

abnormal myocardial fiber morphology ( J:36089 )

• the average length of myofibrils is ~50% that of control lengths; the A bands of myofibrils occupy the entire sarcomeric length and I bands cant't be detected; A band length is reduced by approximately 75% relative to controls

• mutant sarcomeres are only 79% as long as controls

• myofibrils display numerous areas where thin filaments are absent compared to controls which have regular hexameric arrays of thick and thin filaments

decreased cardiac muscle contractility ( J:36089 )

• mutants display increased time to peak pressure, indicative of reduced contractility