A non-human animal model for muscle cell atrophy is provided. In certain embodiments, the animal comprises a cell comprising a nuclear genome comprising a biologically active atrogen gene in operable linkage with a reporter construct comprising: i. a first coding sequence for an optically detectable protein and ii. a second coding sequence for a secreted reporter enzyme wherein expression of the atrogen gene is induced upon initiation of muscle cell atrophy, thereby resulting in production of the secreted reporter enzyme and the first optically detectable protein by the cell. Screening assays that employ the non-human animal are also provided.