Phenotypes associated with this allele

• Allele Symbol: Cyp26b1^em1Oncl
• Allele Name: endonuclease-mediated mutation 1, Ondine Cleaver
• Allele ID: MGI:7314519
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Cyp26b1^em1Oncl/Cyp26b1^em1Oncl	involves: C57BL/6J	MGI:7444029

Genotype
MGI:7444029

hm1

• Allelic Composition: Cyp26b1^em1Oncl/Cyp26b1^em1Oncl
• Genetic Background: involves: C57BL/6J

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

cardiovascular system

ventricular septal defect ( J:325730 )

• at E18.5, five of 14 (35.7%) of hearts exhibit ventricular septal defects

abnormal semilunar valve morphology ( J:325730 )

• semilunar valves (SLs) show upregulation of known retinoic acid (RA) target genes (Pbx1, Hnf3a, and Ret), indicating dysfunction in RA metabolism

• at E15.5, Pbx1 immunoreactivity is broadly increased in the SL valve endothelium and mesenchyme, as well as in the surrounding aortic root

• at E15.5, Ret is expressed in endothelial and mesenchymal cells of SL valves, but not detected in wild-type SL valves

• at E15.5, Hnf3a shows an increase specifically in the SL valve endothelium; by E18.5, increased Hnf3a is seen in both endothelial and mesenchymal cells of SL valves

abnormal aortic valve cusp morphology ( J:325730 )

• at E18.5, aortic valve leaflets show a 55% increase in overall cellularity relative to wild-type leaflets

• at E18.5, aortic valve leaflets show a significant decrease in overall cell density, suggesting an increase in extracellular matrix (ECM) production; however, no change in apoptosis is detected by cleaved caspase 3 staining

• enlarged aortic valve leaflets are likely a result of excess outflow tract mesenchymal cell proliferation

thick aortic valve cusps ( J:325730 )

• at E18.5, aortic valve leaflets show a ~2.5-fold increase in aortic valve leaflet width relative to wild-type aortic valve leaflets

• by E18.5, the proportion of proliferating pHH3+ cells is significantly higher than that in wild-type aortic valve leaflets (8.9% vs 5.7%, respectively)

• thickened aortic valve leaflets are due in part to increased endothelial and mesenchymal cell proliferation in the remodeling valves

• however, valve leaflet width is normal in both atrioventricular and semilunar valves at E15.5, and no differences in proliferation are detected at E16.5 in any of the valves

enlarged aortic valve ( J:325730 )

• aortic valve enlargement is due, at least in part, to increased cell proliferation

heart valve hyperplasia ( J:325730 )

• at E18.5, increase in overall cellularity is specific to the aortic valve; pulmonary, mitral, and tricuspid valve sizes are less affected

homeostasis/metabolism

abnormal vitamin A metabolism ( J:325730 )

• semilunar valves show upregulation of known retinoic acid (RA) target genes (Pbx1, Hnf3a, and Ret), indicating dysfunction in RA metabolism