Phenotypes associated with this allele

• Allele Symbol: Ldhb^tm1.2Choy
• Allele Name: targeted mutation 1.2, Yun-Hoon Choung
• Allele ID: MGI:8242645
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ldhb^tm1.2Choy/Ldhb^tm1.2Choy	involves: 129S4/SvJae * C57BL/6	MGI:8242648

Genotype
MGI:8242648

hm1

• Allelic Composition: Ldhb^tm1.2Choy/Ldhb^tm1.2Choy
• Genetic Background: involves: 129S4/SvJae * C57BL/6

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

hearing/vestibular/ear

decreased cochlear outer hair cell number ( J:371573 )

• decreased hair cell number in the middle and basal turns at 5 months but not at 2 months of age

• by 10 months of age hair cell loss is seen across the basal, middle, and apical turns unlike in wild-type mice where loss is seen only in the middle and basal turns

• however, no inner hair cell loss is detected

decreased cochlear hair cell stereocilia number ( J:371573 )

• decreased stereocilia number in the middle and basal turns at 5 months but not at 2 months of age

type II spiral ligament fibrocyte degeneration ( J:371573 )

• diffuse degeneration at 5 months of age

type IV spiral ligament fibrocyte degeneration ( J:371573 )

• diffuse degeneration at 5 months of age

increased or absent threshold for auditory brainstem response ( J:371573 )

• increased thresholds at 8, 16, and 32 kHz, statistically significant at 16 and 32 kHz, at 5 months but not at 2 months of age

• thresholds continue to increase with age

• high-frequency thresholds are impaired while thresholds at lower frequencies is preserved

increased susceptibility to age-related hearing loss ( J:371573 )

• early onset of progressive hearing loss

nervous system

abnormal neuron mitochondrial morphology ( J:371573 )

• more severe increase in the proportion of fragmented mitochondria and distortion of cristae in spiral ganglion cells at 10 months of age compared to wild-type controls

decreased cochlear outer hair cell number ( J:371573 )

• decreased hair cell number in the middle and basal turns at 5 months but not at 2 months of age

• by 10 months of age hair cell loss is seen across the basal, middle, and apical turns unlike in wild-type mice where loss is seen only in the middle and basal turns

• however, no inner hair cell loss is detected

decreased cochlear hair cell stereocilia number ( J:371573 )

• decreased stereocilia number in the middle and basal turns at 5 months but not at 2 months of age

abnormal cochlear ganglion morphology ( J:371573 )

• progressive loss of spiral ganglion neurons at 5 and 10 months of age, compared to wild-type controls where loss is not seen until 10 months of age

• more severe increase in the proportion of fragmented mitochondria and distortion of cristae in spiral ganglion cells at 10 months of age compared to wild-type controls

cellular

abnormal neuron mitochondrial morphology ( J:371573 )

• more severe increase in the proportion of fragmented mitochondria and distortion of cristae in spiral ganglion cells at 10 months of age compared to wild-type controls

increased apoptosis ( J:371573 )

• increased apoptosis of type II and type IV fibrocytes in the cochlear lateral wall at 5 months of age

• increased apoptosis in spiral ganglion neurons at 5 and 10 months of age

skeleton

type II spiral ligament fibrocyte degeneration ( J:371573 )

• diffuse degeneration at 5 months of age

type IV spiral ligament fibrocyte degeneration ( J:371573 )

• diffuse degeneration at 5 months of age