Phenotypes Associated with This Genotype

Genotype
MGI:3712360

• Allelic Composition: Scyl1^mdf/Scyl1^mdf
• Genetic Background: B6C3Fe a/a-Scyl1^mdf/J

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

nervous system

abnormal cerebellum morphology ( J:121817 )

abnormal Purkinje cell morphology ( J:121817 )

• axonal swelling reduced

abnormal Purkinje cell dendrite morphology ( J:121817 )

• dendritic arborization and ramification reduced

decreased Purkinje cell number ( J:121817 )

• overall reduction in number becoming very pronounced by 45 days of age

abnormal cerebellum vermis morphology ( J:121817 )

• marked atrophy of the cerebellar vermis

abnormal innervation ( J:30384 )

abnormal innervation pattern to muscle ( J:30384 )

• collateral reinnervation sometimes occurs and has a reticulated appearance

motor neuron degeneration ( J:30384 )

• vacuolation of motor neurons in the spinal cord and brain stem

• vacuolated cells in the spinal cord found exclusively in the ventral horn

• degenerating fibers often found in proximity to normal fibers

abnormal axon morphology ( J:121817 )

• axonal degeneration and loss of axons

• fewer myelinated fibers in the sciatic nerve and no large myelinated fibers

abnormal myelin sheath morphology ( J:30384 , J:121817 )

• fragmentation of myelin sheaths (J:30384)

• hypomyelination (J:121817)

abnormal neuromuscular synapse morphology ( J:30384 )

• motor nerve terminals are disorganized in shape

abnormal optic nerve morphology ( J:121817 )

• visibly smaller in cross section

• increase of small diameter myelinated fibers

• thinner myelinated sheaths

abnormal motor nerve collateral sprouting ( J:30384 )

• axonal sprouting

behavior/neurological

decreased grip strength ( J:30384 )

• progressive reduction of forelimb grip strength

abnormal stationary movement ( J:30384 )

abnormal tail movements ( J:30384 )

• loss of tail mobility over time

hindlimb paralysis ( J:30384 )

• hind-limbs are paralytic at 3 months of age but flexion of hindlimb digits is still possible

muscle

skeletal muscle fiber necrosis ( J:30384 )

• isolated necrotic fibers found in most muscles

muscular atrophy ( J:30384 )

• quadriceps femoris becomes atrophied sometimes involving entire muscle fascicles

• triceps brachii usually severely atrophied sometimes involving entire muscle fascicles

• extent of atrophy varies in different muscles and individuals

• some muscles are usually spared

abnormal muscle electrophysiology ( J:30384 )

• abnormal spontaneous electromyographic activity

• amplitude of muscle action potential about 1/3 of controls

abnormal muscle regeneration ( J:30384 )

• isolated regenerating fibers found in most muscles

skeleton

abnormal pelvic girdle bone morphology ( J:30384 )

• dorso-ventral flattening of the pelvis by 3 months of age

vision/eye

abnormal optic nerve morphology ( J:121817 )

• visibly smaller in cross section

• increase of small diameter myelinated fibers

• thinner myelinated sheaths

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
hereditary ataxia		DOID:0050951		J:121817