Analysis Tools
behavior/neurological
head bobbing
(
J:62565
)
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• on a predominantly CD-1 background, 61% of adult homozygotes show rapid head bobbing
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hyperactivity
(
J:62565
)
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• on a predominantly CD-1 background, 61% of adult homozygotes are hyperactive
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• Background Sensitivity: unexpectedly, 61% of adult homozygotes on a predominantly CD-1 background (5 to 9 backcross generations) show a circling phenotype that is not observed in either a 129 or a C57BL/6J background
• cicling is first evident when pups are old enough to walk and continues into adulthood
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hearing/vestibular/ear
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• on a predominantly CD-1 background, adult homozygotes twirl excessively when picked up by the tail and display classic waltzer phenotypes indicating vestibular dysfunction
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nervous system
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• at E13.5, homozygotes of a predominantly CD-1 background show delayed outgrowth of efferent projections into both the ipsilateral and contralateral inner ears
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• at E13.5, both ipsilateral and contralateral projections of inner ear efferent (IEE) axons are disoriented and exhibit a temporary difficulty in reaching their targets
• as a result, ectopic caudal extensions are formed at the midline of the hindbrain with a 1- to 2-day delay in arriving at the ear end organs
• at E14.5 or later, axon tracing of IEEs shows a fairly normal number of crossed and uncrossed fibers in mutant mice
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• mossy fiber pruning is defective
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• at E13.5, homozygotes of a predominantly CD-1 background display delayed growth of efferent projections into both the ipsilateral and contralateral inner ears
• at this stage, growth cones have not yet reached into the sensory epithelia of the semicircular canals and there is an aberrant pausity of axons destined for the saccule and utricle
• in contrast, growth of afferent projections into the inner ear are normal, with afferents reaching all sensory epithelia by E12.5
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• infra-pyramidal bundle (IPB) axons are longer than in wild-type mice
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cellular
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• at E13.5, homozygotes of a predominantly CD-1 background show delayed outgrowth of efferent projections into both the ipsilateral and contralateral inner ears
|
|
• at E13.5, both ipsilateral and contralateral projections of inner ear efferent (IEE) axons are disoriented and exhibit a temporary difficulty in reaching their targets
• as a result, ectopic caudal extensions are formed at the midline of the hindbrain with a 1- to 2-day delay in arriving at the ear end organs
• at E14.5 or later, axon tracing of IEEs shows a fairly normal number of crossed and uncrossed fibers in mutant mice
|
|
• mossy fiber pruning is defective
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