Mice: Some of the rodent residents of Joseph Takahashi's neurobiology lab at Northwestern University exercise at odd times of the day. Those with one mutant copy of the gene clock follow a 25-hour day, while those with two mutant genes follow a 26- to 29-hour day for two weeks, then simply stop cycling.
The photosynthetic set: At the University of Virginia, associate professor of biology Steven Kay and postdoctoral research associate Andrew Millar scan transgenic seedlings of the mustard weed Arabidopsis for those that glow to the beat of a different internal drummer. The bioluminescence assay is the result of creating transgenic plants with the firefly luciferase gene hooked to a chlorophyll binding protein, which is normally expressed during daytime. Spray seedlings with luciferase's substrate and the resulting glow tells researchers where -- and when -- the chlorophyll gene is active. Millar and Kay identified mutants whose chlorophyll genes turn ...
