Phenotypes associated with this allele
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Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lama2dy mutation
(2 available);
any
Lama2 mutation
(177 available)
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nervous system
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• after P7, the number of Schwann cell nuclei increases
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• mice exhibit a 36% decrease in myelinated nerves at the sciatic I level
(J:5331)
• in the dorsal and ventral roots of the spinal and cranial peripheral nerves, Schwann cells fail to separate and ensheathe axons so that groups of closely apposed naked axons, normally seen only in early stages, persist into adulthood
(J:5331)
• fetal axons of less than 0.5 um diameter lack myelin or Schwann cell ensheathment in the peripheral nervous system
(J:12730)
• the onset of myelination is delayed compared to in wild-type mice
(J:12730)
• the length of myelinated segments added to an existing population are shorter than in wild-type mice
(J:12730)
• myelinated internodal lengths are shorter than in wild-type mice in the peripheral nervous system
(J:12730)
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• transport of dopamine-beta-hydrolase in nerves is reduced compared to in wild-type mice
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homeostasis/metabolism
growth/size/body
cellular
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• the basement membrane of Schwann cells around myelinated axons is gapped whereas it is absent in amyelinated zones
(J:5565)
• nodes exhibit unusually long segments bare of basement membrane
(J:5565)
• the internodal gap in the basement membrane of peripheral nerves at the nodes of Ranvier is lengthened compared to in wild-type mice
(J:5866)
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Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lama2dy mutation
(2 available);
any
Lama2 mutation
(177 available)
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hearing/vestibular/ear
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• spaces normally filled with perilymph and endolymph fluids are obliterated with a fibrotic debris
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• the structural integrity of the organ of Corti is altered with supporting and hair cells not exhibiting their normal vertical height and a slight compression of the organ, especially at the apical half turn
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• hair cells in the organ of Corti not exhibiting their normal vertical height
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• supporting not exhibiting their normal vertical height
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• mice exhibit a degeneration of vestibular structures
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• mice exhibit an increase in brainstem auditory threshold compared to wild-type mice
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behavior/neurological
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• mice exhibit impaired motor activity
• however, no circling or head twisting is observed
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• mice stumble when walking
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nervous system
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• hair cells in the organ of Corti not exhibiting their normal vertical height
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• few if any nerve fibers remain in the ear
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craniofacial
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• the posterior portion of the skull is slightly expanded while the medial portion is narrowed
• mice exhibit wider braincases, a slight flexion in the middle and rotated mandibles
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• spaces normally filled with perilymph and endolymph fluids are obliterated with a fibrotic debris
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• skull width relative to skull length increase is more pronounced than in Lama2dy-2J homozygotes
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reproductive system
growth/size/body
homeostasis/metabolism
muscle
endocrine/exocrine glands
skeleton
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• the posterior portion of the skull is slightly expanded while the medial portion is narrowed
• mice exhibit wider braincases, a slight flexion in the middle and rotated mandibles
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• spaces normally filled with perilymph and endolymph fluids are obliterated with a fibrotic debris
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• skull width relative to skull length increase is more pronounced than in Lama2dy-2J homozygotes
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Allelic Composition |
Lama2dy/Lama2dy
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Genetic Background |
involves: 129P1/Re |
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Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lama2dy mutation
(2 available);
any
Lama2 mutation
(177 available)
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mortality/aging
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• most homozygotes die between 1 and 6 months of age
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muscle
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• unusual proliferation of sarcolemmal nuclei
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• in contrast to wild-type, space between fibers is increased and an increase in interstitial tissue is observed
• in some cases, fat cells are found between fibers
• unusual proliferation of nuclei both within and between the fibers
• affected fibers appear rounded rather than polygonal in transverse section
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• individual fibers exhibit size variations
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• some fibers, although otherwise normal, contain long chains of centrally, rather than peripherally, located nuclei
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• muscular atrophy proceeds from hind quarters to axial and forelimb musculature
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• mild paralysis is first observed at 3.5 week and progresses to hindlimb dragging by 8 weeks
• eventually there is a complete loss of locomotor function and premature death
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skeleton
behavior/neurological
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• ataxia with occasional unilateral paresis is first observed at 3.5 weeks of age
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• unilateral paresis begins at 3.5 weeks progressing to bilateral paresis
• paresis is accompanied by spasmodic flexion and flaccid extension in hindlimbs
• mild paralysis is first observed at 3.5 weeks and progresses to hindlimb dragging by 8 weeks
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• failure to mate putatively due to physical disability
• gonad morphology is normal
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growth/size/body
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• by two weeks of age, body weight is less than wildtype
• weight difference continues through out lifespan
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• cachexia as well as thinning and ruffling of fur is observed by 8 weeks
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Allelic Composition |
Lama2dy/Lama2dy
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Genetic Background |
involves: 129P1/Re * C57BL/6 |
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Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lama2dy mutation
(2 available);
any
Lama2 mutation
(177 available)
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muscle
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• only a few necrotic fibers are found at 10 days of age but by 15 days of age there are necrotic fibers undergoing phagocytosis and fibers with internal nuclei and by 20 days of age there is an increase in both the number of necrotic and regenerating fibers and a variability in the muscle fiber size
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• mutant muscles contain myofibers of different calibers with increased fiber loss and the presence of fibrotic lesions
(J:134367)
• evident by 15 days of age
(J:152525)
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• the total number of muscle fibers in the soleus is decreased after 15 days of age
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• proliferation of interstitial tissue is found skeletal muscle by 20 days of age
(J:152525)
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• mice exhibit a decreased regenerative capacity with a reduction of total fiber number and a decrease in centrally localized nuclei compared to in wild-type mice
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nervous system
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• peripheral nerve roots in the spine exhibit severe hypomyelination
• despite adherence of Schwann cells to axons and extension of processes, myelination is not completed
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cellular
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• the basal lamina of muscles is discontinuous, sparse and enmeshed with collagen fibrils from the collapse of the reticular lamina
• the basal lamina of Schwann cells is sparse
• the basal lamina was absent from non-myelinating Schwann cells
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Allelic Composition |
Lama2dy/Lama2dy
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Genetic Background |
involves: 129P1/ReJ |
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Find Mice |
Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Lama2dy mutation
(2 available);
any
Lama2 mutation
(177 available)
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mortality/aging
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• only 66% of mice survive the 24 week experiment compared to 86% of C3tm1Hrc Lama2dy homozygotes
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muscle
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• mice display hindlimb contractures
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• forelimb strength is decreased compared to in C3tm1Hrc Lama2dy homozygotes
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growth/size/body
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• compared to C3tm1Hrc Lama2dy homozygotes
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immune system
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• mice exhibit increased deposition of IgG in muscles compared to in wild-type mice
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• mice exhibit increased deposition of IgM in muscles compared to in wild-type mice and C3tm1Hrc Lama2dy homozygotes
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skeleton
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• unlike C3tm1Hrc Lama2dy homozygotes
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hematopoietic system
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• mice exhibit increased deposition of IgG in muscles compared to in wild-type mice
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• mice exhibit increased deposition of IgM in muscles compared to in wild-type mice and C3tm1Hrc Lama2dy homozygotes
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Allelic Composition |
C3tm1Hrc/C3tm1Hrc Lama2dy/Lama2dy
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Genetic Background |
either: (involves: 129S2/SvPas * 129P1/ReJ) or (involves: 129X1/SvJ * 129P1/ReJ) |
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mortality/aging
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• 86% of mice survive the 24 week experiment compared to only 66% of Lama2dy homozygotes
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muscle
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• fewer macrophages are found within muscles compared to in Lama2dy homozygotes
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behavior/neurological
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• mice exhibit 25% to 20% greater forelimb strength than Lama2dy homozygotes
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growth/size/body
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• compared to Lama2dy homozygotes
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immune system
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• mice exhibit increased deposition of IgG in muscles compared to in wild-type mice
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• mice exhibit reduce deposition of IgM in muscles compared to in Lama2dy homozygotes
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• mice exhibit increased deposition of IgM in muscles compared to in wild-type mice
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hematopoietic system
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• mice exhibit increased deposition of IgG in muscles compared to in wild-type mice
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• mice exhibit reduce deposition of IgM in muscles compared to in Lama2dy homozygotes
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• mice exhibit increased deposition of IgM in muscles compared to in wild-type mice
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nervous system
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• the rostral migratory stream is less compact than in wild-type mice and cells do not form chains as in wild-type mice
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