digestive/alimentary phenotype

• abnormal fungiform papillae morphology
  • loss of fungiform papillae is seen in 2 week old mutants and remaining papillae are smaller
  (MGI Ref ID J:82462)

growth/size/body region phenotype

• decreased body size
  • mice are reduced in size compared to control littermates
  (MGI Ref ID J:17123)

• abnormal fungiform papillae morphology
  • loss of fungiform papillae is seen in 2 week old mutants and remaining papillae are smaller
  (MGI Ref ID J:82462)

hearing/vestibular/ear phenotype

• abnormal type I vestibular cell
  • no nerve chalicies are found associated with type I hair cells of the vestibule
  (MGI Ref ID J:17123)

• abnormal crista ampullaris morphology
  • ampullar cristae completely lack innervation
  (MGI Ref ID J:82462)

• deafness
  • loss of hearing
  (MGI Ref ID J:82462)

mammalian phenotype

• hearing/vestibular/ear phenotype
  • Normal - innervation of the cochlear inner and outer hair cells appears similar to controls
  (MGI Ref ID J:17123)
  • Normal - mice respond to auditory stimuli
  (MGI Ref ID J:17123)
  • Normal - despite abnormal innervation of the vestibular compartment, the structural integrity of the organ of Corti, macula of the saccula and utricle, and the cristae of the semicircular ducts appear similar to controls
  (MGI Ref ID J:17123)

• nervous system phenotype
  • Normal - no differences are seen in the morphology of the central and peripheral nerve processes from the trigeminal, geniculate, petrose and nodose ganglia at E10.5-11.5
  (MGI Ref ID J:17123)

behavior/neurological phenotype

• head bobbing
  (MGI Ref ID J:17123)

• impaired balance
  (MGI Ref ID J:17123)

• hyperactivity
  (MGI Ref ID J:17123)

• circling
  (MGI Ref ID J:17123)

• spinning
  (MGI Ref ID J:17123)

• head tilt
  (MGI Ref ID J:17123)

• impaired limb coordination
  (MGI Ref ID J:17123)

mortality/aging

• postnatal lethality, incomplete penetrance
  (MGI Ref ID J:82462)
  • most homozygotes die in the second postnatal week, with rare survivors achieving adult stages
  (MGI Ref ID J:17123)

nervous system phenotype

• small geniculate ganglion
  (MGI Ref ID J:82462)
  • approximately half of the neurons are lost from the geniculate ganglion at E18.5
  (MGI Ref ID J:25566)

• small nodose ganglion
  • approximately 65% of the neurons are lost from the nodose ganglion at P14-16
  (MGI Ref ID J:17123)
  • greater than half of the neurons are lost from the nodose-petrosal ganglion at E18.5
  (MGI Ref ID J:25566)(MGI Ref ID J:82462)

• abnormal vestibular nerve morphology
  • innervation of the vestibular compartment of the inner ear is severely compromised
  (MGI Ref ID J:17123)
  • no nerve chalicies are found associated with type I hair cells of the vestibule
  (MGI Ref ID J:17123)
  • only small fiber bundles enter the saccule, utricle and ampulla of the semicircular ducts compared to controls; the remaining fibers terminate in the connective tissue adjacent to the sensory epithelia of the saccule, utricle and cristae of the semicurcular ducts
  (MGI Ref ID J:17123)
  • ar ducts
  (MGI Ref ID J:17123)

• decreased sensory neuron number
  • Normal - no difference in the number of facial motor neurons is seen compared to controls
  (MGI Ref ID J:25566)
  • significant loss of all sensory neuron types in the nodose-petrosal, geniculate and vestibular ganglia in homozygous mice
  (MGI Ref ID J:25566)
  • the numbers of neurons in many sensory ganglia are reduced compared to controls
  (MGI Ref ID J:17123)
  • Normal - the number of facial motor neurons and sympathetic superior cervical ganglion neurons is not different from controls
  (MGI Ref ID J:17123)

• small L4 dorsal root ganglion
  (MGI Ref ID J:82462)
  • approximately 30% of the neurons are lost from the L4 DRG at P14-16
  (MGI Ref ID J:17123)

• abnormal cochlear ganglion morphology
  • loss of spiral ganglion neurons by 25% at P0 and 29% at P17 in the cochlea
  (MGI Ref ID J:82462)

• abnormal trigeminal nerve morphology
  • mice exhibit a 43% loss of trigeminal neurons at birth
  (MGI Ref ID J:123022)

• small vestibular ganglion
  • approximately 75% of the neurons are lost from the vestibular ganglion at E18.5
  (MGI Ref ID J:25566)
  • approximately 80% of the neurons are lost from the vestibular ganglion at P14-16
  (MGI Ref ID J:17123)
  • vestibular neurons appear atrophic
  (MGI Ref ID J:17123)

• small petrosal ganglion
  • greater than half of the neurons are lost from the nodose-petrosal ganglion at E18.5
  (MGI Ref ID J:25566)

• small trigeminal ganglion
  • approximately half of the neurons are lost from the trigeminal ganglion at P14-16
  (MGI Ref ID J:17123)

• abnormal sensory neuron innervation pattern
  • loss of outer hair cell innervation in the apex, middle and basal turns of the cochlea
  (MGI Ref ID J:82462)

• abnormal type I vestibular cell
  • no nerve chalicies are found associated with type I hair cells of the vestibule
  (MGI Ref ID J:17123)

• abnormal vestibular ganglion morphology
  • in co-cultures of wild-type vestibular ganglion neurons with mutant hair cells, very few (2 of 200) wild-type neurons contact a mutant hair cell and diameter of the nerve fiber is thinner and shows less branching on the surface of the mutant hair cell than seen in all wild-type cultures
  (MGI Ref ID J:82462)
  • n seen in all wild-type cultures
  (MGI Ref ID J:82462)

• increased neuron apoptosis
  • at E12 and E14, neuron apoptosis is increased 143% and 155%, respectively, compared to in wild-type mice
  (MGI Ref ID J:123022)

• small mesencephalic trigeminal nucleus
  • approximately half of the neurons are lost from the mesencephalic trigeminal nucleus at P14-16
  (MGI Ref ID J:17123)

• abnormal innervation
  • ampullar cristae completely lack innervation
  (MGI Ref ID J:82462)

cellular phenotype

• increased neuron apoptosis
  • at E12 and E14, neuron apoptosis is increased 143% and 155%, respectively, compared to in wild-type mice
  (MGI Ref ID J:123022)

craniofacial phenotype

• abnormal fungiform papillae morphology
  • loss of fungiform papillae is seen in 2 week old mutants and remaining papillae are smaller
  (MGI Ref ID J:82462)

cellular phenotype

• abnormal neuron apoptosis
  • cell death in culture following the withdrawal of NGF is delayed
  (MGI Ref ID J:46125)
  • sympathetic neuron apoptosis is developmentally delayed
  (MGI Ref ID J:46125)

nervous system phenotype

• abnormal neuron apoptosis
  • sympathetic neuron apoptosis is developmentally delayed
  (MGI Ref ID J:46125)
  • cell death in culture following the withdrawal of NGF is delayed
  (MGI Ref ID J:46125)

• abnormal neuron morphology
  • mice exhibit an increased in sympathetic neuron number (21 318+/-1 627 compared to 15 690+/-617 in wild-type mice) and size
  (MGI Ref ID J:46125)

• increased neuron number
  (MGI Ref ID J:46125)

nervous system phenotype

• abnormal sensory neuron innervation pattern
  • innervation of the fungiform papillae is reduced with a shortfall in the geniculate ganglion neurons that supply taste neurons to the fungiform papillae
  (MGI Ref ID J:90280)

taste/olfaction phenotype

• abnormal gustatory papillae taste bud morphology
  • at P7 homozygous mice have 79% fewer vallate taste buds than wild-type mice
  (MGI Ref ID J:90280)