Conserved Gene Involved in Progressive Neural Degeneration

Model organisms such as Drosophila are receiving increased attention for studies of human neurodegenerative disease. Although the merit of such systems for genetic studies is apparent, the relevance of a neurodegenerative phenotype in flies, whose lifespan is measured in weeks, to the long duration of human neurodegenerative diseases would seem less clear. However, two articles in this issue of the Journal provide additional evidence for the potential value of such studies. Finley et al. describe a novel loss-of-function mutant, blue cheese, that has a reduced life span, protein aggregates in the neuropil of “aged” animals, and neuronal apoptosis. The blue cheese protein, whose function is unknown, is expressed in the cytoplasm of CNS neurons and has a human homolog. In contrast, Palladino et al. report a neurodegenerative phenotype in Drosophila with mutations in a known protein, the subunit of the Na/K ATPase. The sodium pump is fundamental to the maintenance of ion gradients in normal neurons. These mutants, identified in a screen for temperature-sensitive paralytic mutants, showed age-dependent, spongioform neurodegeneration but did not show protein aggregates. The mutations caused a reduced life span but could also cause hyperexcitability and seizures. Œ Development/Plasticity/Repair