This is a proposal to undertake a comprehensive study that will reveal the structure, expression patterns, and basic functional properties of all potassium channels in C. elegans. The project will provide the first glimpse of the entire K channel set in one animal, without favoring any cell, tissue type or abundance class, revealing aspects of genomic organization that are not discernible without the complete gene sequences. Initially, all sequence information revealed by the C. elegans genomic project at Washington University will be compiled, and then the expression patterns of individual K channels will be determined. Because there are an estimated 100 potassium channels in an organism with only 302 neurons, many of these channels may be under coordinated regulation for expression; this may be required for complex electrical behavior. This study may lead to a profile not only of structure an functional properties, but also tissue distribution and amount and timing of expression. These data may serve as a model for interpreting the human genome sequence data, and may also lead to clinical applications.