mortality/aging
• the remaining 50% were obtained at birth but generally died from intra-abdominal hemorrhage within 2 hours of birth
• however, one of 60 mutant pups survived until P10, and a second pup died immediately following a tail biopsy at P14
|
• about 50% of mutant embryos died at E9-E10
• a decrease in surviving embryos became evident by E11.5, with highly significant differences at E15.5 and E18.5
|
cardiovascular system
hemorrhage
(
J:36444
)
• scattered microscopic hemorrhages were detected in various tissues, most commonly in the mesenchyme of the face
|
• at birth, ~50% of homozygotes displayed massive intra-abdominal hemorrhage
|
• occasionally, homozygotes showed cutaneous bleeding, particularly over the head
|
embryo
• at E9.5, many homozygous null embryos had only 12-16 somites (versus 20-25 somites in wild-type), indicating a developmental delay
|
• by E9.5, wild-type, heterozygous and ~60% of homozygous null embryos had a well developed heartbeat and yolk-sac circulation; the remaining homozygotes showed some degree of abnormal yolk-sac organization
• in these mutants, the yolk-sac circulation appeared sluggish, and the yolk sac had a granular appearance
|
• in 5/11 yolk sacs from E9.5 null embryos, the visceral endoderm appeared flattened, with few blood islands
• the remaining six appeared to have slightly fewer hematopoietic precursors, but vascular plexes were present in the mesoderm
|
integument
• occasionally, homozygotes showed cutaneous bleeding, particularly over the head
|