Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): The picture shows a top view image of an eas (ccg-2)-luc-I Neurospora crassa strain acquired with a charge-coupled-device camera. High levels of bioluminescence can be detected following expression of a fully optimized luciferase (luc-I) gene in N. crassa. The chart illustrates how luminescence oscillates in a circadian manner, when luciferase is under the control of the core clock gene frequency (frq) promoter. The inset pictures correspond to representative time points from the time series therein plotted. Images were false colored to allow clear visualization of luminescence intensity variation. (See related article on page 28.)