Animal model · BEGINNER LESSON
SOD1-G93A
SOD1-G93A is a genetically engineered mouse model that carries the human SOD1 gene with the G93A mutation. It is used to study amyotrophic lateral sclerosis (ALS) by measuring neuromuscular decline, such as muscle weakness, motor loss, and survival changes.
What it is and what is measured
SOD1-G93A is a transgenic mouse model, meaning the mouse has been engineered to carry an added gene from another species. Here, the added gene is human SOD1 with the G93A mutation, a change at amino acid 93. Researchers use these mice to measure ALS-like disease progression, especially neuromuscular function, muscle weakness, motor neuron loss, atrophy, paralysis, and survival. A phenotypic neurological scoring system can quickly rate how severely the mice are affected.
[1] A Quick Phenotypic Neurological Scoring System for Evaluating ... [2] Gene therapy for ALS: A review - PMC [3] Pathological insights from amyotrophic lateral sclerosis animal models
How it works biologically
The SOD1 gene encodes an enzyme called Cu/Zn superoxide dismutase 1, which helps break down superoxide radicals, a type of reactive oxygen species, into less harmful molecules. In ALS-linked SOD1 mutations, the mutant protein is thought to damage cells through toxic gain of function, meaning the altered protein acquires harmful activity. Reported effects include protein aggregation, oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and loss of motor neurons.
[2] Gene therapy for ALS: A review - PMC [3] Pathological insights from amyotrophic lateral sclerosis animal models
Why researchers use it
This model became common because it has a clear genetic link to familial ALS and reproduces several features seen in human disease, including progressive weakness, muscle wasting, paralysis, and death. It is widely used in preclinical drug studies, especially for therapies aimed at SOD1. The mouse helps researchers test whether a treatment changes measurable disease outcomes before studies move to humans.
[1] A Quick Phenotypic Neurological Scoring System for Evaluating ... [2] Gene therapy for ALS: A review - PMC
Limitations and interpretation
SOD1-G93A mice do not represent all ALS. Human ALS often involves pathology that is not the same as SOD1-linked disease, so results may not translate broadly. Even within this model, there is biological variability. A scoring system made for high-copy SOD1-G93A mice may miss unusual cases, such as mice that first show forelimb or tongue-related deficits instead of hindlimb weakness. It may also be unsuitable for low-copy SOD1-G93A mice or other ALS models such as TDP-43 mice.
[1] A Quick Phenotypic Neurological Scoring System for Evaluating ... [2] Gene therapy for ALS: A review - PMC [3] Pathological insights from amyotrophic lateral sclerosis animal models
SEE THE IDEA
From mutant gene to measured disease signs
The mouse carries a human gene with the G93A amino-acid change.
The mutant protein is linked to harmful cellular stress and aggregation.
Researchers observe weakness, motor loss, atrophy, and paralysis.
Scoring systems track neuromuscular function and survival over time.
genetic change leads to altered protein effects, which lead to measurable disease signs in the mouse
The model connects a defined mutation to observable neuromuscular decline that researchers can score.
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Sources and further reading
This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.