Phenotypes Associated with This Genotype

Genotype
MGI:5698703

• Allelic Composition: Rab18^m1Hongc/Rab18^m1Hongc
• Genetic Background: C57BL/6J-Rab18^m1Hongc

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

behavior/neurological

hyporesponsive to tactile stimuli ( J:220974 )

• in the tail-flick test, mutants show a delayed response

• application of a force of 0.4g induces only about 1% paw withdrawal response in mutants compared to 100% response in wild-type mice, indicating impaired touch perception

limb grasping ( J:220974 )

• when suspended by the tail, mutants retract hindlimbs to the body and clench their paws

ataxia ( J:220974 )

• sensory ataxia

impaired coordination ( J:220974 )

• mutants show impaired performance on the beam walking test beginning at 6 weeks of age; mutants spend a longer time to walk across the beam with progressive increase in foot slippage with age such that 20% of 7 month old mutants and 60% of 10 month old mutants fall off the beam

abnormal gait ( J:220974 )

• mice exhibit a stomping gait in the hind limbs in which they lift their hindlimbs high and hit the ground hard in walking

• 2 week old mice exhibit waving tail as well as excessive side to side movements in walking, with stomping gait becoming explicit at 5 months of age

• mice develop a spastic gait on the hindlimbs at 10 months of age

increased thermal nociceptive threshold ( J:220974 )

• in the hot plate test, paw withdrawal latencies to heat are increased, indicating impaired pain perception

endocrine/exocrine glands

small testis ( J:220974 )

♂

growth/size/body

decreased body weight ( J:220974 )

• mean body weight is 12% lower than of wild-type mice

nervous system

abnormal corpus callosum morphology ( J:220974 )

• thinner corpus callosum

optic nerve degeneration ( J:220974 )

• fibers in the optic nerves undergo degeneration with hyperdense axoplasm, watery swelling, and loosening myelin sheath

abnormal dorsal spinal root morphology ( J:220974 )

• mutants show an increase in the number of degenerating axons in the dorsal root of the lumber spinal nerves as early as 1.5 months of age

• however, no loss is seen in the dorsal root ganglion and ventral roots of the spinal nerves are normal

axon degeneration ( J:220974 )

• progressive axonal degeneration in the optic nerves, dorsal column of the spinal cord, and sensory roots of the spinal nerves but not in motor roots

reproductive system

small testis ( J:220974 )

♂

vision/eye

optic nerve degeneration ( J:220974 )

• fibers in the optic nerves undergo degeneration with hyperdense axoplasm, watery swelling, and loosening myelin sheath

microphthalmia ( J:220974 )

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Warburg micro syndrome 3		DOID:0110718	OMIM:614222	J:220974