Phenotypes associated with this allele

• Allele Symbol: Hopx^tm1Eno
• Allele Name: targeted mutation 1, Eric N Olson
• Allele ID: MGI:2389233
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Hopx^tm1Eno/Hopx^tm1Eno	involves: 129S6/SvEvTac	MGI:3626084

Genotype
MGI:3626084

hm1

• Allelic Composition: Hopx^tm1Eno/Hopx^tm1Eno
• Genetic Background: involves: 129S6/SvEvTac

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

mortality/aging

embryonic lethality during organogenesis, incomplete penetrance ( J:79152 )

• on an isogenic 129/Sv background, ~10% of homozygotes die at E11.5 from cardiac insufficiency; as a result, viable homozygotes represent only 17% of offspring at P10

• Background Sensitivity: on a mixed 129Sv x C57BL/6J genetic background, most homozygotes are viable and represent 23% of heterozygous offspring at P10, closely approximating the expected Mendelian ratio

cardiovascular system

thin myocardium ( J:79152 )

• on an isogenic 129/Sv background, ~10% of E11.5 homozygotes display a hypocellular, thin-walled ventricular myocardium with numerous ruptures throughout the ventricular walls

enlarged heart ( J:79152 )

increased heart weight ( J:79152 )

• at P1-P28, viable homozygotes exhibit a ~20% increase in heart weight/body weight ratio relative to wild-type mice; increase difference persists through adulthood

cardiac hypertrophy ( J:79152 )

• at 6 months of age, a subset of viable homozygotes develop late-onset hypertrophy of cardiac myocytes

heart hyperplasia ( J:79152 )

• at P1 and P28, viable homozygotes of an isogenic or mixed genetic background exhibit a ~30% increase in the number of cardiac myocytes; however, no cardiomyocyte hypertrophy is noted up to 4 weeks of age

• postnatal cardiac hypercellularity is in stark contrast to the hypocellular cardiac phenotype of embryos that die at E11.5, suggesting a finely tuned mechanism that governs the balance between cardiomyocyte proliferation and differentiation

thick ventricular wall ( J:79152 )

• at P1, viable homozygotes display increased ventricular wall thickness relative to wild-type mice

cardiac fibrosis ( J:79152 )

• at 6 months of age, mutant hearts with cardiomyocyte hypertrophy exhibit severe dilation and fibrosis

abnormal cardiovascular system physiology ( J:79152 )

hemopericardium ( J:79152 )

• on an isogenic 129/Sv background, ~10% of E11.5 homozygotes exhibit pericardial hemorrhaging

decreased cardiac muscle contractility ( J:79152 )

• at 6 months of age, those homozygotes with hypertrophic hearts display impaired cardiac contractility or cardiac dysfunction

abnormal fetal cardiomyocyte proliferation ( J:79152 )

• at P1, >66% of viable homozygotes exhibit prolonged cardiomyocyte proliferation, as shown by a 19-fold increase in the number of cells staining positive for the mitotic marker phospho-histone H3

• however, delayed withdrawal of mutant cardiomyocytes from the cell cycle is transient, as no phospho-H3-positive cardiomyocytes are detected at 4 weeks of age

embryo

embryonic growth arrest ( J:79152 )

• on an isogenic 129/Sv background, ~10% of homozygotes display a developmental arrest at E11.5

muscle

thin myocardium ( J:79152 )

• on an isogenic 129/Sv background, ~10% of E11.5 homozygotes display a hypocellular, thin-walled ventricular myocardium with numerous ruptures throughout the ventricular walls

abnormal muscle physiology ( J:79152 )

decreased cardiac muscle contractility ( J:79152 )

• at 6 months of age, those homozygotes with hypertrophic hearts display impaired cardiac contractility or cardiac dysfunction

abnormal fetal cardiomyocyte proliferation ( J:79152 )

• at P1, >66% of viable homozygotes exhibit prolonged cardiomyocyte proliferation, as shown by a 19-fold increase in the number of cells staining positive for the mitotic marker phospho-histone H3

• however, delayed withdrawal of mutant cardiomyocytes from the cell cycle is transient, as no phospho-H3-positive cardiomyocytes are detected at 4 weeks of age

homeostasis/metabolism

hemopericardium ( J:79152 )

• on an isogenic 129/Sv background, ~10% of E11.5 homozygotes exhibit pericardial hemorrhaging

cellular

abnormal fetal cardiomyocyte proliferation ( J:79152 )

• at P1, >66% of viable homozygotes exhibit prolonged cardiomyocyte proliferation, as shown by a 19-fold increase in the number of cells staining positive for the mitotic marker phospho-histone H3

• however, delayed withdrawal of mutant cardiomyocytes from the cell cycle is transient, as no phospho-H3-positive cardiomyocytes are detected at 4 weeks of age

growth/size/body

enlarged heart ( J:79152 )

increased heart weight ( J:79152 )

• at P1-P28, viable homozygotes exhibit a ~20% increase in heart weight/body weight ratio relative to wild-type mice; increase difference persists through adulthood

cardiac hypertrophy ( J:79152 )

• at 6 months of age, a subset of viable homozygotes develop late-onset hypertrophy of cardiac myocytes

heart hyperplasia ( J:79152 )

• at P1 and P28, viable homozygotes of an isogenic or mixed genetic background exhibit a ~30% increase in the number of cardiac myocytes; however, no cardiomyocyte hypertrophy is noted up to 4 weeks of age

• postnatal cardiac hypercellularity is in stark contrast to the hypocellular cardiac phenotype of embryos that die at E11.5, suggesting a finely tuned mechanism that governs the balance between cardiomyocyte proliferation and differentiation