Phenotypes associated with this allele

• Allele Symbol: Gjc1^tm1Kni
• Allele Name: targeted mutation 1, Kiyomasa Nishii
• Allele ID: MGI:1861740
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Gjc1^tm1Kni/Gjc1^tm1Kni	involves: 129S/SvEv * C57BL/6	MGI:2176922

Genotype
MGI:2176922

hm1

• Allelic Composition: Gjc1^tm1Kni/Gjc1^tm1Kni
• Genetic Background: involves: 129S/SvEv * C57BL/6

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:63214 )

• homozygotes die of heart failure at ~E9.5-E10; no homozygotes are obtained after E12

cardiovascular system

absent trabeculae carneae ( J:63214 )

• at E9.5, homozygotes display severely reduced trabeculation in the walls of the common ventricular chamber

• in contrast, the cellularity of the outer mantle layer remains relatively normal

abnormal heart development ( J:63214 )

• homozygotes exhibit a cardiac dysmorphology as early as at the 4- to 5-somite stage

absent atrioventricular cushions ( J:63214 )

• at E9.5, homozygotes exhibit significantly less cushion cells relative to wild-type mice; however, the cardiac jelly is still present

abnormal heart looping ( J:63214 )

• at E9.5, homozygotes display a primitive atrium in the lower dorsal part of the heart, indicating a looping defect

enlarged heart ( J:63214 )

• at E9.5 and E10.5, homozygotes exhibit an enlarged heart relative to body size

decreased cardiac muscle contractility ( J:63214 )

• at E10.5, all mutant hearts fail to beat and display spasmodic contractions of focal cardiac myocytes

heart block ( J:63214 )

• homozygotes initiate heart contractions at the 3-somite stage but display a conduction block within 24 hrs after the first contractions

• from E9.5 onward, atrial contractions or transmission of the atrial impulses through the AV canal, or both, are severely impaired

• in addition, the outflow tract fails to expand and contract in accordance with the ventricular contractions

embryo

embryonic growth arrest ( J:63214 )

• homozygotes cease growth and development between E9.5 and E10.5

decreased embryo size ( J:63214 )

• at E9.5 and E10.5, homozygotes are smaller than wild-type embryos

small placenta ( J:63214 )

• at E10.5, homozygotes have slightly smaller placentas

growth/size/body

enlarged heart ( J:63214 )

• at E9.5 and E10.5, homozygotes exhibit an enlarged heart relative to body size

decreased embryo size ( J:63214 )

• at E9.5 and E10.5, homozygotes are smaller than wild-type embryos

muscle

absent trabeculae carneae ( J:63214 )

• at E9.5, homozygotes display severely reduced trabeculation in the walls of the common ventricular chamber

• in contrast, the cellularity of the outer mantle layer remains relatively normal

decreased cardiac muscle contractility ( J:63214 )

• at E10.5, all mutant hearts fail to beat and display spasmodic contractions of focal cardiac myocytes

cellular

increased apoptosis ( J:63214 )

• from E9.0 onward, homozygotes exhibit extensive apoptosis in the mesenchyme of branchial arches and forebrain

• notably, mutant cardiac walls are relatively resistant to apoptosis