Phenotypes Associated with This Genotype

Genotype
MGI:7579276

• Allelic Composition: Morc2a^em1Snupy/Morc2a⁺
• Genetic Background: involves: C57BL/6

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

behavior/neurological

abnormal cognition ( J:341847 )

• reduced spontaneous alternation in Y-maze test

limb grasping ( J:341847 )

• abnormal hindlimb grasping in tail suspension test

ataxia ( J:341847 )

• cerebellar ataxia

impaired coordination ( J:341847 )

♀ • shorter latency to fall in rotarod test starting at age 6-9 months

decreased locomotor activity ( J:341847 )

♀ • lower activity and shorter distance traveled in metabolic cage

paraparesis ( J:341847 )

mortality/aging

prenatal lethality, incomplete penetrance ( J:341847 )

• het x het matings yield heterozygotes at 2:3 ratio vs WT, instead of 2:1

muscle

muscle phenotype ( J:341847 )

N • normal heart muscle weight

skeletal muscle atrophy ( J:341847 )

• smaller tibialis anterior (TA), soleus (Sol), gastrocnemius (GC) and quadriceps femoris (Quad) muscles

• immune cell infiltration of Quad muscles

skeletal muscle fiber atrophy ( J:341847 )

• atrophy of central core of muscle fibers

nervous system

increased neuron apoptosis ( J:341847 )

• activation of Caspase 3 and 9 in the cerebellum, cerebrum, spinal cord, sciatic nerve and Quad muscle

decreased Purkinje cell number ( J:341847 )

cerebellum atrophy ( J:341847 )

• reduced vermis size at age 15 month

decreased spinal cord ventral horn cell number ( J:341847 )

• loss of motor neurons

abnormal myelination ( J:341847 )

• fewer large myelinated fibers in sciatic nerve and depletion of myelinated fibers in axons at age 15 months

• some thin myelin sheaths at age 15 months

• increase in small myelinated fibers in axons at age 4 and 15 months

abnormal action potential ( J:341847 )

• reduced compound muscle action potential (CMAP) and sensory nerve action potential (SNAP)

decreased nerve conduction velocity ( J:341847 )

• reduced motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV)

cellular

increased neuron apoptosis ( J:341847 )

• activation of Caspase 3 and 9 in the cerebellum, cerebrum, spinal cord, sciatic nerve and Quad muscle

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease axonal type 2Z		DOID:0110181	OMIM:616688	J:341847