Phenotypes Associated with This Genotype

Genotype
MGI:3605067

• Allelic Composition: Chrng^tm1Mtak/Chrng^tm1Mtak
• Genetic Background: involves: 129X1/SvJ * C57BL/6

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

mortality/aging

perinatal lethality, incomplete penetrance ( J:99894 )

• fewer than expected homozygotes are found at birth and only half of these are born alive

postnatal lethality, complete penetrance ( J:99894 )

• homozygotes born alive survive for about 2 days and survival can be extended with intraperitoneal saline infusion

respiratory system

abnormal breathing pattern ( J:99894 )

• 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

abnormal skeletal muscle fiber morphology ( J:99894 )

• muscle fibers have lower density of cross-striation and multiple clusters of acetylcholine receptors on a single muscle fiber

increased variability of skeletal muscle fiber size ( J:99894 )

• muscle fibers have unequal size

abnormal diaphragm morphology ( J:99894 )

• acetylcholine receptors are more broadly distributed along the central endplate and are unequal in size and shape

abnormal muscle physiology ( J:99894 )

• muscle fibers are hyperexcitable and occasionally exhibit fibrillatory action potentials immediately upon impalement

nervous system

abnormal neuromuscular synapse morphology ( J:99894 )

• at P0 nerve terminals in the forelimbs are well-developed but sprouted suggesting a history of inactivity

abnormal miniature endplate potential ( J:99894 )

• 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

abnormal suckling behavior ( J:99894 )

• homozygotes do not suckle

hindlimb paralysis ( J:99894 )

• homozygotes can move their forelimbs but not their hindlimbs

homeostasis/metabolism

cyanosis ( J:99894 )

• homozygotes dead at birth appear cyanotic

dehydration ( J:99894 )