Hindlimb gait defects due to motor axon loss and reduced distal muscles in a transgenic mouse model of Charcot-Marie-Tooth type 2A
| Autor: | Don W. Cleveland, Scott A. Detmer, Christine Vande Velde, David C. Chan |
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| Rok vydání: | 2007 |
| Předmět: |
Genetically modified mouse
Lameness Animal Recombinant Fusion Proteins Green Fluorescent Proteins MFN2 Mice Transgenic Hindlimb Biology GTP Phosphohydrolases Central nervous system disease Mitochondrial Proteins Mice Degenerative disease Charcot-Marie-Tooth Disease Genetics medicine Animals Humans Axon Molecular Biology Genetics (clinical) DNA Primers Motor Neurons Base Sequence Homozygote Membrane Proteins General Medicine Anatomy medicine.disease Muscle atrophy Axons Mitochondria medicine.anatomical_structure Phenotype nervous system Mutagenesis Site-Directed Neuron medicine.symptom Neuroscience |
| Zdroj: | Human molecular genetics. 17(3) |
| ISSN: | 1460-2083 |
| Popis: | Charcot–Marie–Tooth (CMT) disease type 2A is a progressive, neurodegenerative disorder affecting long peripheral motor and sensory nerves. The most common clinical sign is weakness in the lower legs and feet, associated with muscle atrophy and gait defects. The axonopathy in CMT2A is caused by mutations in Mitofusin 2 (Mfn2), a mitochondrial GTPase necessary for the fusion of mitochondria. Most Mfn2 disease alleles dominantly aggregate mitochondria upon expression in cultured fibroblasts and neurons. To determine whether this property is related to neuronal pathogenesis, we used the HB9 promoter to drive expression of a pathogenic allele, Mfn2^(T105M), in the motor neurons of transgenic mice. Transgenic mice develop key clinical signs of CMT2A disease in a dosage-dependent manner. They have a severe gait defect due to an inability to dorsi-flex the hindpaws. Consequently, affected animals drag their hindpaws while walking and support themselves on the hind knuckles, rather than the soles. This distal muscle weakness is associated with reduced numbers of motor axons in the motor roots and severe reduction of the anterior calf muscles. Many motor neurons from affected animals show improper mitochondrial distribution, characterized by tight clusters of mitochondria within axons. This transgenic line recapitulates key motor features of CMT2A and provides a system to dissect the function of mitochondria in the axons of mammalian motor neurons. |
| Databáze: | OpenAIRE |
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