Analysis Tools
mortality/aging
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• increase in rate of postnatal death, especially during the first 1-2 weeks after birth
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Allele Symbol Allele Name Allele ID |
L1camtm1Sor targeted mutation 1, Philippe Soriano MGI:1857443 |
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| Summary |
5 genotypes
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| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
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• increase in rate of postnatal death, especially during the first 1-2 weeks after birth
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| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
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• increase in rate of postnatal death, especially during the first 1-2 weeks after birth
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| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
Cerebellar abnormalities in L1camtm1Sor/Y Nrcamtm1Gmt/Nrcamtm1Gmt mice
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• do not detect any mutants at P8
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• body weights of pups are 40-70% of control littermates at P3-P6
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• cerebellar dysgenesis
• cerebellar fissures are less developed
• thickness of the inner granule layer is reduced by 40-50%
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• marker analysis indicates defects in foliation
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• thickness of the external granule layer is reduced by 10-30%
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• cerebellar lobes are less developed
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• marker analysis indicates possible defects in granule cells during cerebellar development
• thickness of the inner granule layer is reduced by 40-50%
• thickness of the external granule layer is reduced by 10-30%
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| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
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N |
• males survive >18 months
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• males are born at ~40% of expected frequency (84/211 total males)
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• initially males are ~60% size of wild-type littermates
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• by adulthood, males attain ~80% the size of wild-type littermates
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N |
• the optic chiasm, corpus callosum, and spinal commissural projection in mutants show normal axonal pathfinding and crossing projections, in contrast to the pyramidal decussation
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• in P3-P5 animals, very few corticospinal axons grow to the contralateral dorsal columns at the pyramidal decussation; many axons instead turn ventrally at midline and enter the contralateral pyramid
• in one animal, aberrant axons turn rostrally in contralateral pyramid and project back towards midbrain; in other animals, axons can't be traced beyond decussation
• no axons are apparent caudal to the decussation, either ventrally or dorsally
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• in adult males examined, corticospinal axons project normally to the medulla, but at the level of the decussation, a substantial portion of axons fail to cross the midline and instead pass ipsilaterally into the dorsal columns
• no axon labeling is detected more caudally than the cervical spinal cord in male mutants
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• dragging of hindlimbs is observed in some mice >12 months of age
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N |
• although males are sterile, testis contain germ cells
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• some individuals are able to breed but most are effectively sterile
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• adult mutants have sunken eyes
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• adult mutants have lacrimous eyes
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• Background Sensitivity: with age, mice on congenic 129/Sv agouti background develop patches of black fur on their backs
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• Background Sensitivity: with age, mice on congenic 129/Sv agouti background develop patches of black fur on their backs
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• Background Sensitivity: mice have abnormally long hind-paw toenails (4-5 mm) on congenic 129/Sv background
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• in P3-P5 animals, very few corticospinal axons grow to the contralateral dorsal columns at the pyramidal decussation; many axons instead turn ventrally at midline and enter the contralateral pyramid
• in one animal, aberrant axons turn rostrally in contralateral pyramid and project back towards midbrain; in other animals, axons can't be traced beyond decussation
• no axons are apparent caudal to the decussation, either ventrally or dorsally
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• Background Sensitivity: mice have abnormally long hind-paw toenails (4-5 mm) on congenic 129/Sv background
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| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
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• mutants show reduced body weights
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• cultured neurons grown on L1-Fc chimera (molecule of Fc region of human IgG and entire extracellular domain of human L1) show impaired ability to extend neurites compared to wild-type neurons; fewer neurons show outgrowth and extend shorter neurites compared to wild-type neurons
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• total brain volume is significantly reduced compared to controls
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• volume of fourth ventricle is increased compared to controls
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• volume of fourth ventricle is increased compared to controls
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• significant dilation of lateral ventricles is observed
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• shape is different in mutants; distal part connecting ampulla of aqueduct to fourth ventricle is longer in mutants
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• cerebellar volume is significantly reduced compared to controls
• ratio between surface of cerebellum and surface of total brain (in midsagittal sections) is reduced compared to wild-type
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• average surface area of vermis is reduced compared to controls; ratio of surface area of vermis to cerebral cortex surface area is smaller
• hypoplasia is most prominent in lobule 6; one or two of the three sublobule of lobule 6 are underdeveloped or missing in mutants
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• developing embryos have aberrant projections of sensory afferents in the spinal cord
• significant numbers of aberrant projections from the dorsal funiculus to the dorsal horn are evident at E12.5 compared to virtually none in the wild-type controls
• the number of aberrant projections increase at E13.5 and again at E14.5 and always remain at least 4-fold higher than controls
• by E14.5, the aberrant projections are also greater in length than controls with projections sometimes almost reaching the midline
• the number of aberrant projections is less than what is observed in Cntn2 null homozgyotes
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• developing embryos have aberrant projections of sensory afferents from the dorsal funiculus to the dorsal horn
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• cultured dorsal root ganglion cells have much less repulsion to ventral spinal cord explants than controls
• in culture, E13.5 sensory axons are completely refractory to repulsion mediated by Semaphorin-3A
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• mutants show impaired spatial learning in Morris water-maze paradigm in probe trials where platform is removed; mutants spend significantly less time in target quadrant and majority of time is localized to periphery
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• in open field test, most mutants spend less time exploring, instead running in circles around perimeter of cage
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• in rotarod trials, mutants display difficulties in maintaining balance, and fall on at least one attempt, compared to wild-type controls
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• mutants show ~50% of total cage activity that is displayed by wild-type controls
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• when a cage containing 2 female mice is placed in center of open field test cage, mutants do not adapt exploration pattern to this external stimulus; mutants still display circling of cage periphery while wild-type spend 45% of their exploratory behavior within 10 cm of the cage
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• cultured neurons grown on L1-Fc chimera (molecule of Fc region of human IgG and entire extracellular domain of human L1) show impaired ability to extend neurites compared to wild-type neurons; fewer neurons show outgrowth and extend shorter neurites compared to wild-type neurons
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Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO) |
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last database update 04/30/2024 MGI 6.23 |
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