Phenotypes Associated with This Genotype

Genotype
MGI:6490343

• Allelic Composition: Matr3^em1Tcp/Matr3^em1Tcp
• Genetic Background: C57BL/6J-Matr3^em1Tcp

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

mortality/aging

premature death ( J:298091 )

• mice reach end-stage earlier

growth/size/body

decreased body size ( J:298091 )

• mice show a size difference beginning at 20 weeks of age and onwards

decreased body weight ( J:298091 )

• mice fail to gain weight at the same rate as controls starting at 15 and 21 weeks of age for males and females, respectively

weight loss ( J:298091 )

• weight plateaus until 60 weeks of age, at which point some mice start to show significant weight loss and reach endpoint

behavior/neurological

impaired contextual conditioning behavior ( J:298091 )

• males show reduced freezing time in the contextual fear conditioning tests

• however, females show no differences in this test

impaired cued conditioning behavior ( J:298091 )

• males show reduced freezing time in the cued fear conditioning test

• however, females show no differences in this test

impaired righting response ( J:298091 )

• mice exhibit a delayed righting reflex at 40 weeks of age; the righting time increases with age and is seen in almost all mice by 60 weeks of age

limb grasping ( J:298091 )

• about 73% of mice begin to show a limb clasping phenotype at 20 weeks of age

ataxia ( J:298091 )

• mice exhibit ataxia, severe gait disturbances and occasional hind limb dragging near end-stage

impaired coordination ( J:298091 )

• starting at 10 weeks of age, mice exhibit reduced latency to fall off the rotarod and progressively worsen with age

• mice are slower and have greater difficulty crossing the dowl and progressively worsen over time

decreased grip strength ( J:298091 )

• mice exhibit a reduction in muscle strength at 30 and 55 weeks of age using the inverted grid test

decreased vertical activity ( J:298091 )

• mice exhibit reduced length of time standing on their hind limbs starting at 10 weeks of age and decreases with age

nervous system

increased microglial cell activation ( J:298091 )

• mice show increased activated microglia in the cerebellum and lower lumbar spinal cord at 30 weeks of age

Purkinje cell degeneration ( J:298091 )

• extensive loss of Purkinje cells is seen in 60-week old mice

small cerebellum ( J:298091 )

• reduction in cerebellum size in 60-week old mice but not in 6-week old mice

astrocytosis ( J:298091 )

• mice show increased astrogliosis in the cerebellum at 30 weeks of age

abnormal neuromuscular synapse morphology ( J:298091 )

• mice exhibit an increase in the percentage of partially denervated endplates, indicating affected neuromuscular junctions

• mice exhibit smaller endplate sizes in tibialis anterior muscles

axon degeneration ( J:298091 )

• mice show an increase in the number of neurofilament accumulations near the presynaptic terminals, suggesting axonal degeneration

axonal spheroids ( J:298091 )

• mice at end-stage exhibit spheroids in the granule cell layer

muscle

decreased skeletal muscle fiber size ( J:298091 )

• average tibialis anterior and gastrocnemius muscle fiber sizes are reduced

• however, no prominent mopathic changes are seen

hematopoietic system

increased microglial cell activation ( J:298091 )

• mice show increased activated microglia in the cerebellum and lower lumbar spinal cord at 30 weeks of age

immune system

increased microglial cell activation ( J:298091 )

• mice show increased activated microglia in the cerebellum and lower lumbar spinal cord at 30 weeks of age

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
amyotrophic lateral sclerosis type 21		DOID:0060212	OMIM:606070	J:298091