Phenotypes associated with this allele

• Allele Symbol: Pknox2^em1Lff
• Allele Name: endonuclease-mediated mutation 1, Lucia F Franchini
• Allele ID: MGI:7868152
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Pknox2^em1Lff/Pknox2^em1Lff	involves: FVB	MGI:8158703

Genotype
MGI:8158703

hm1

• Allelic Composition: Pknox2^em1Lff/Pknox2^em1Lff
• Genetic Background: involves: FVB

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

hearing/vestibular/ear

abnormal inner hair cell synaptic ribbon morphology ( J:344156 )

• at P60, mice show a significantly higher number of CtBP2 puncta (presynaptic ribbons) per inner hair cell (IHC) in the high-frequency (basal) region of the cochlea

• however, no changes in the number of CtBP2 puncta or overall morphology of the organ of Corti and the cochlea are detected by prestin immunolabeling in outer hair cells (OHCs)

abnormal hearing electrophysiology ( J:344156 )

abnormal auditory brainstem response waveform shape ( J:344156 )

• at P60, auditory brainstem response (ABR) peak I amplitudes are significantly higher than in wild-type controls at 80 dB SPL

• increase in suprathreshold ABR peak I amplitude correlates with a higher number of colocalized synaptic puncta (CtBP2/GluA2) in the high-frequency (basal) region of the cochlea

decreased threshold for auditory brainstem response ( J:344156 )

• at P60, mice exhibit significantly reduced auditory brainstem response (ABR) thresholds at high frequencies (22.65 kHz, 32 kHz and 45.25 kHz)

decreased distortion product otoacoustic emission threshold ( J:344156 )

• at P60, mice exhibit a slight decrease in distortion product otoacoustic emission (DPOAE) thresholds that is statistically significant only at the highest frequency tested (45.25 kHz)

nervous system

abnormal inner hair cell synaptic ribbon morphology ( J:344156 )

• at P60, mice show a significantly higher number of CtBP2 puncta (presynaptic ribbons) per inner hair cell (IHC) in the high-frequency (basal) region of the cochlea

• however, no changes in the number of CtBP2 puncta or overall morphology of the organ of Corti and the cochlea are detected by prestin immunolabeling in outer hair cells (OHCs)

abnormal ribbon synapse morphology ( J:344156 )

• at P60, mice show a significantly higher number of IHCs-auditory nerve synapses in the cochlear basal (high-frequency) region, with an ~28% increase in the number of CtBP2 puncta (presynaptic ribbons), GluA2 receptor patches (postsynaptic afferent terminals), and synapse puncta (ribbon synapses) per IHC in the basal turn

• however, the number of presynaptic ribbons, postsynaptic afferent terminals, and synaptic counts are unaffected in the apical and medial cochlear regions

behavior/neurological

behavior/neurological phenotype ( J:344156 )

N • in an open field test, mice exhibit no significant differences in locomotor activity, exploration, spatial memory, and anxiety-like behavior relative to wild-type controls