Phenotypes for Hey1 Hey2 MGI:3043229 MGI Mouse

prenatal lethality, complete penetrance ( J:89444 )

• no double homozygous embryos survive and all show abnormalities by E10.5

• reduction in expression of arterial specific markers suggests impaired arterial cell fate specification in double homozygotes

abnormal dorsal aorta morphology ( J:89444 )

• the dorsal aortae are frequently reduced or missing on one or both sides of double homozygous embryos probably as a result of impaired aortic wall formation

abnormal intersomitic vessel morphology ( J:89444 )

• intersomitic vessels formed by angiogenetic sprouting do form but appear less organized than in controls

abnormal placental labyrinth vasculature morphology ( J:89444 )

• at E10.5 no embryonic blood vessels can be detected in the labyrinthine layer

• however, embryonic vessels are seen in the allantois and chorionic plate

abnormal cardinal vein morphology ( J:89444 )

• the cardinal veins are frequently reduced or missing on one or both sides of double homozygous embryos

decreased angiogenesis ( J:89444 )

• vascular patterning is coarse especially in the head with many truncated vessels without finely branched trees

absent myocardial trabeculae ( J:89444 )

• at E9.5 the heart lacks trabeculae

thin myocardium ( J:89444 )

• at E9.5 the heart has initiated looping but the myocardium is much thinner

abnormal heart ventricle morphology ( J:89444 )

• at E9.5 - E10.5 the ventricular portion of the heart does not fully enlarge however contractions and blood circulation appear to occur

distended pericardium ( J:89444 )

• at E10.5 balloon like pericardial sacs are seen in homozygous mutants

hemorrhage ( J:89444 )

• at E9.5 evidence of hemorrhage can be seen

• at E10.5 massive hemorrhage is seen in the head, trunk, and pericardial cavity of homozygous mutants

embryonic growth retardation ( J:89444 )

• at E9.5 double homozygous embryos appear developmentally retarded

abnormal neural tube morphology ( J:89444 )

• at E9.5 the neural tube is thinner and the surrounding mesenchymal cells appear sparse

incomplete somite formation ( J:89444 )

• somite formation ceases after E9.5 after 21-26 somites although the somites that do form are normal in size and shape

abnormal placenta labyrinth morphology ( J:89444 )

• at E10.5 the labyrinthine layer lacks fetal blood circulation and appears very cell-rich without the intermingling of maternal and embryonic blood spaces seen in controls

abnormal placental labyrinth vasculature morphology ( J:89444 )

• at E10.5 no embryonic blood vessels can be detected in the labyrinthine layer

• however, embryonic vessels are seen in the allantois and chorionic plate

abnormal umbilical cord morphology ( J:89444 )

• formation of an umbilical cord is initiated; however, after E9.5 the connection between embryo and placenta does not mature into a thicker umbilical cord

pale yolk sac ( J:89444 )

abnormal vitelline vascular remodeling ( J:89444 )

• at E9.5 the primitive vascular plexus is present but fails to remodel and by E10.5 is unchanged or degenerating

• by E11.5 when most double homozygous embryos are necrotic no vasculature is left in the yolk sac