Phenotypes associated with this allele
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Smpxem2Jgao mutation
(0 available);
any
Smpx mutation
(3 available)
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hearing/vestibular/ear
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• stereocilia degeneration starts at P150 and degeneration process is milder than in males
• the shortest row of outer hair cell stereocilia begin to degenerate in the basal turn, but are normal at middle and apical turns
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• auditory brainstem response threshold shifts first appear in females at 5 months of age
• females show a milder elevation of mean threshold than males, indicating less severe hearing loss in females than in males
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• mice exhibit progressive hearing loss
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nervous system
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• stereocilia degeneration starts at P150 and degeneration process is milder than in males
• the shortest row of outer hair cell stereocilia begin to degenerate in the basal turn, but are normal at middle and apical turns
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Smpxem2Jgao mutation
(0 available);
any
Smpx mutation
(3 available)
|
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hearing/vestibular/ear
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• auditory brainstem response threshold shifts appear at 5 months of age, to a similar extent as is homozygous females
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• mice exhibit hearing loss
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| Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Smpxem2Jgao mutation
(0 available);
any
Smpx mutation
(3 available)
|
|
|
hearing/vestibular/ear
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• cochlea shows progressive degeneration of hair cell bundles from the shortest row starting at P30 and by P150, outer hair cell stereocilia in the basal turn are usually completely degenerated, or if still present, they are very short and show signs of fusion
• the shortest row of outer hair cell bundle in the middle and apical turn are mostly degenerated at P150
• however, no changes in inner hair cell stereocilia are seen
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• outer hair cell body shows cellular edema, with edematous changes in the organelles and vacuolation of the mitochondria, at the end phase of stereocilia degeneration
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• a large number of outer hair cell death is seen at 5 months, especially at the basal turn of the basilar membrane and with aging; cell death of outer hair cells spreads from the base to the apex and outer hair cell survival at the basal turn is decreased
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• auditory brainstem response (ABR) threshold shifts first appear in males at 3 months of age
• males show a greater elevation of mean threshold than females, indicating more severe hearing loss in males than females
• threshold shift appears earlier in high frequency
• hearing loss gradually spreads from high to low frequency until the whole spectrum is affected by 5 months of age, with a 20 db threshold shift in 4 kHz pure tone
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• mice show threshold shifts in distortion product otoacoustic emission (DPOAE) at frequency of 12, 16, 20, and 32 kHz at 3 months of age
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• 1- to 2-month-old mice show 20-30 dB threshold shift in ABR after 2 hours of noise exposure and thresholds do not recover after one week as in wild-type mice, indicating that noise-exposure induced unrecoverable hearing loss
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• mice exhibit progressive hearing loss
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nervous system
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• cochlea shows progressive degeneration of hair cell bundles from the shortest row starting at P30 and by P150, outer hair cell stereocilia in the basal turn are usually completely degenerated, or if still present, they are very short and show signs of fusion
• the shortest row of outer hair cell bundle in the middle and apical turn are mostly degenerated at P150
• however, no changes in inner hair cell stereocilia are seen
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• outer hair cell body shows cellular edema, with edematous changes in the organelles and vacuolation of the mitochondria, at the end phase of stereocilia degeneration
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• a large number of outer hair cell death is seen at 5 months, especially at the basal turn of the basilar membrane and with aging; cell death of outer hair cells spreads from the base to the apex and outer hair cell survival at the basal turn is decreased
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Analysis Tools