Phenotypes Associated with This Genotype

Genotype
MGI:6198715

• Allelic Composition: Tg(Mnx1-Mfn2*T105M,-EGFP)1Dcc/Tg(Mnx1-Mfn2*T105M,-EGFP)1Dcc
• Genetic Background: Not Specified

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

behavior/neurological

abnormal limb posture ( J:132035 )

• limp hindpaws due to a failure to dorsiflex at the ankle

• at rest, mice leave their hind limbs extended behind their bodies rather than bringing them under their haunches

abnormal gait ( J:132035 )

• mice exhibit an abnormal gait characterized by dragging of hindlimbs and supporting themselves on the hind knuckles rather than soles

• gait defects are evident from birth

• however, mice perform well on the rotarod and beam walking assays

cellular

abnormal mitochondrial morphology ( J:132035 )

• many motor neurons have highly aggregated mitochondria that cluster along the axon

growth/size/body

decreased body weight ( J:132035 )

• 15% reduction in body weight at weaning (P20)

limbs/digits/tail

abnormal autopod morphology ( J:132035 )

• mice often have clenched hindpaws due to an inability to spread the toes

abnormal hindlimb morphology ( J:132035 )

• hindlimb defects are incompletely penetrant, with 60% bilaterally affected, 26% unilaterally affected, and 14% unaffected

• hindlimb defects are evident from birth

• however, no defect is seen in the forelimbs

abnormal tail morphology ( J:132035 )

• tails are severely deformed

short tail ( J:132035 )

• mice have drastically shorter tails that are severely deformed

muscle

decreased skeletal muscle size ( J:132035 )

• mice exhibit dramatically reduced anterior musculature of the lower leg

• however, the posterior calf muscle mass is normal

• mice with asymptomatic hindlimbs have an intermediate, variable mass of anterior muscle

• foot muscles are smaller in size

muscle weakness ( J:132035 )

• severe weakness of the distal hindlimb muscles

nervous system

abnormal motor neuron morphology ( J:132035 )

• motor roots have fewer motor axons

• lumbar motor roots are smaller

• motor roots at L4 and L5 contain about 40% fewer axons compared to controls

• loss of motor axons is most severe in the small caliber axons

• however, no reduction in the number of axons in sensory roots is seen

• many motor neurons show improper mitochondrial distribution, with tight clusters of mitochondria within axons

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease type 2A2A		DOID:0110155	OMIM:609260	J:132035