mortality/aging
• homozygotes born alive survive for about 2 days and survival can be extended with intraperitoneal saline infusion
|
• fewer than expected homozygotes are found at birth and only half of these are born alive
|
respiratory system
• shallow, irregular and paradoxical (the thorax is depressed corresponding to abdominal distension) respiration is seen
• only the diaphragm muscle is able to support respiration
|
muscle
• muscle fibers have lower density of cross-striation and multiple clusters of acetylcholine receptors on a single muscle fiber
|
• muscle fibers have unequal size
|
• acetylcholine receptors are more broadly distributed along the central endplate and are unequal in size and shape
|
• muscle fibers are hyperexcitable and occasionally exhibit fibrillatory action potentials immediately upon impalement
|
nervous system
• at P0 nerve terminals in the forelimbs are well-developed but sprouted suggesting a history of inactivity
|
• in the proximal forelimb muscle at P0, miniature endplate potentials are subthreshold and never result in action potentials unlike in wild-type mice
|
behavior/neurological
• homozygotes do not suckle
|
• homozygotes can move their forelimbs but not their hindlimbs
|
homeostasis/metabolism
dehydration
(
J:99894
)