All Phenotypes Ky<ky> MGI Mouse

behavior/neurological phenotype ( J:116344 )

N	• mice exhibit no tremor or paralysis, and no defect in ability to hold onto and let go of wire cage bars

abnormal placing response ( J:5353 , J:7750 , J:22972 )

• when held by the tail and placed on a surface, mice show a defective placing reflex, tending to land on their noses instead of on their forefeet (J:5353)

abnormal gait ( J:116344 )

• described as slight waddle

decreased body weight ( J:5353 , J:22972 )

• body weight of adults is reduced up to 30% (J:5353)

• mice weighed only 75% of NMRI controls (J:22972)

abnormal breathing pattern ( J:5353 )

• breathing is difficult

abnormal thoracic vertebrae morphology ( J:5353 )

• progressive erosion of the articulating thoracic vertebral surfaces

abnormal nucleus pulposus morphology ( J:7750 )

absent nucleus pulposus ( J:7750 )

• in some animals, the nucleus pulposus is absent

intervertebral disk degeneration ( J:7750 )

• variable degenerative changes are noted within disks of one animal and between different animals

• all animals showed some degree of degenerative changes between the fifth cervical and third thoracic vertebra

• changes include the loss of cells, loss of distinction between the nucleus pulpousus and annulus fibrosus, loss of the ring-like structure of the annulus and a wedge shape to the disks

• degenerated material may protrude from the disk space (herniation), and may impinge on the spinal cord

kyphosis ( J:5353 , J:7750 )

• variable penetrance; S-shaped kyphosis at the extreme (J:5353)

kyphoscoliosis ( J:22972 )

reduced fertility ( J:5353 )

• both sexes are fertile, but breeding performance is somewhat reduced, especially in females

• viability is seriously impaired in only the most extremely deformed mice

abnormal skeletal muscle morphology ( J:116344 )

• between 6 and 25 days of age, prominent necrosis and regeneration is seen in a number of skeletal muscles

• at 47 days of age, skeletal muscle atrophy is observed, but necrosis and regeneration is rare

• at 136 days of age, all muscle groups show some degree of atrophy and fibrosis is present in gracilis

skeletal muscle necrosis ( J:116344 )

• between 6 and 25 days of age

decreased extensor digitorum longus weight ( J:22972 )

• extensor digitorum longus (EDL) muscle weighs less than 50% of controls

decreased soleus weight ( J:22972 )

• soleus muscle weighs less than 50% of controls

muscle degeneration ( J:116344 )

muscular atrophy ( J:116344 )

• noted at 47 days of age; progressive and affects all muscles by 136 days of age

impaired skeletal muscle contractility ( J:22972 )

• at all ages, soleus muscles develop only 30% of the force produced by controls and EDL muscle develop 60% of the force of normal EDL

nervous system phenotype ( J:116344 )

N	• gross ultrastructure of the peripheral nervous system and the central nervous system appears similar to controls • the motor neuron number in the anterior horn of the spinal cord is similar to controls

abnormal neuromuscular synapse morphology ( J:66943 )

• in soleus and sternomastoid muscle, mutant neuromuscular synapses are abnormally arranged and in numerous small patches rather than in well ordered structures

abnormal motor nerve collateral sprouting ( J:116344 )

• at 31 days of age and later, collateral, pre- and ultraterminal motor nerve sprouting is seen in soleus and erector spinae muscles

homeostasis/metabolism phenotype ( J:116344 )

N	• serum enzyme levels of pyruvate kinase and creatine kinase are similar to controls