Phenotypes Associated with This Genotype

Genotype
MGI:3688608

• Allelic Composition: Pou3f4^tm1Tno/Pou3f4^tm1Tno
• Genetic Background: involves: 129S4/SvJae * C57BL/6

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

hearing/vestibular/ear

abnormal cochlea morphology ( J:57298 )

♀ • at 11 weeks, female homozygotes show pathological changes in the spiral ligament fibrocytes in all turns of the cochlea

♀ • however, no pathological changes in the inner and outer hair cells, stria vascularis, spiral ganglia or auditory nerve are observed

detached Reissner membrane ( J:108889 )

♀ • at >1 year, female homozygotes display detachment of the Reissner's membrane

abnormal spiral ligament fibrocyte morphology ( J:57298 )

♀ • at 11 weeks, female homozygotes show pathological changes in the spiral ligament fibrocytes in all turns of the cochlea

abnormal type I spiral ligament fibrocytes ( J:57298 )

♀ • type I fibrocytes filling the area beneath the stria vascularis have few mitochondria while the surrounding extracellular matrix is extremely thin

abnormal type II spiral ligament fibrocytes ( J:57298 , J:108889 )

♀ • type II fibrocytes in the suprastrial zone have markedly fewer cytoplasmic extensions and both the volume of cytoplasm and the number of mitochondria are significantly reduced (J:57298)

♀ • at >1 year, female homozygotes exhibit ballooning of type II fibrocytes in the suprastrial zone (J:108889)

decreased endocochlear potential ( J:57298 )

♀ • at 11 weeks, female homozygotes exhibit an average EP value of only 39 mV vs 91 mV observed in wild-type females

increased or absent threshold for auditory brainstem response ( J:57298 , J:108889 )

♀ • at 11 weeks, female homozygotes exhibit an average ABR threshold of 92-dB SPL vs 25-dB SPL observed in wild-type females (J:57298)

♀ • at 1 year, aged female homozygotes exhibit an average ABR threshold of 1008.7 dB SPL, whereas aged wild-type females show only a slight increase in ABR thresholds with an average value of 53.910.8 dB SPL (J:108889)

deafness ( J:57298 , J:108889 )

♀ • at 11 weeks, female homozygotes show loss of wave I at 30- to 70-dB SPL, indicating profound deafness (J:57298)

♀ • at 1 year, aged female homozygotes show profound deafness with an average ABR threshold of 1008.7 dB SPL (J:108889)

behavior/neurological

behavior/neurological phenotype ( J:57298 )

♀N • female homozygotes can swim normally, indicating normal vestibular function

skeleton

abnormal spiral ligament fibrocyte morphology ( J:57298 )

♀ • at 11 weeks, female homozygotes show pathological changes in the spiral ligament fibrocytes in all turns of the cochlea

abnormal type I spiral ligament fibrocytes ( J:57298 )

♀ • type I fibrocytes filling the area beneath the stria vascularis have few mitochondria while the surrounding extracellular matrix is extremely thin

abnormal type II spiral ligament fibrocytes ( J:57298 , J:108889 )

♀ • type II fibrocytes in the suprastrial zone have markedly fewer cytoplasmic extensions and both the volume of cytoplasm and the number of mitochondria are significantly reduced (J:57298)

♀ • at >1 year, female homozygotes exhibit ballooning of type II fibrocytes in the suprastrial zone (J:108889)