Phenotypes Associated with This Genotype

Genotype
MGI:2654138

• Allelic Composition: Lama2^dy/Lama2^dy
• Genetic Background: involves: 129P1/Re * C57BL/6

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

muscle

abnormal skeletal muscle fiber morphology ( J:152525 )

• 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

increased variability of skeletal muscle fiber size ( J:134367 , J:152525 )

• 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)

centrally nucleated skeletal muscle fibers ( J:152525 )

decreased skeletal muscle fiber number ( J:152525 )

• the total number of muscle fibers in the soleus is decreased after 15 days of age

skeletal muscle fiber necrosis ( J:152525 )

skeletal muscle interstitial fibrosis ( J:134367 , J:152525 )

• proliferation of interstitial tissue is found skeletal muscle by 20 days of age (J:152525)

impaired skeletal muscle regeneration ( J:134367 )

• 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

myopathy ( J:134367 )

nervous system

abnormal myelination ( J:134367 )

• peripheral nerve roots in the spine exhibit severe hypomyelination

• despite adherence of Schwann cells to axons and extension of processes, myelination is not completed

cellular

abnormal basal lamina morphology ( J:134367 )

• 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