mortality/aging
• no homozygous mutant embryos are recovered after E10.5
|
embryo
• at E10, homozygotes display abnormal vascular morphogenesis in the yolk sac
|
• at E9.5, homozygotes display defects in the development of caudal parts of the embryo
|
• at E9 and E9.5, homozygotes are severely growth retardated relative to heterozygous and wild-type littermates
|
• at E9.5, homozygotes display disorganization of the ventral neural tube
|
• at E8, homozuygotes exhibit a kinked neural tube
|
• at E8, homozygotes display failure of somite segmentation
• by E9.5, mutant embryos show disorganization of the trunk
|
cardiovascular system
• at E10, homozygotes display abnormal vascular morphogenesis in the yolk sac
|
• at E9.5, homozygotes display an underdeveloped heart
|
• at E9.5, homozygotes exhibit small unlooped hearts
|
small heart
(
J:83376
)
• at E9.5, the heart is smaller than normal
|
• at E9.5, homozygotes display distention of the pericardial sacs
|
nervous system
• at E9.5, homozygotes display disorganization of the ventral neural tube
|
• at E8, homozuygotes exhibit a kinked neural tube
|
growth/size/body
• at E9 and E9.5, homozygotes are severely growth retardated relative to heterozygous and wild-type littermates
|
cellular
• in vitro, secretion of beta-amyloid (Abeta) peptides is abolished in primary embryonic fibroblasts (MEFs) established from E9.5 homozygous mutant embryos
• failure to generate Abeta peptides is accompanied by destabilization of the presenilin/gamma-secretase complex and accumulation of beta-amyloid precursor protein (APP)-C terminal fragments
• cell surface reinternalization of APP is significantly delayed in mutant fibroblasts, indicating that increased accumulation of APP reflects defects in presenilin-dependent APP trafficking
|