Light-to-dark transition of genes. Synechocystis, a type of bacterium that can g...

Light-to-dark transition of genes. Synechocystis, a type of bacterium that can grow and survive under a wide range of conditions, is used by scientists to model DNA behavior. In the Journal of Bacteriology (July 2002), scientists isolated genes of the bacterium responsible for photosynthesis and respiration and investigated the sensitivity of the genes to light. Each gene sample was grown in an incubator in “full light.” The lights were then extinguished, and any growth of the sample was measured after 24 hours in the dark (“full dark”). The lights were then turned back on for 90 minutes (“transient light”), followed immediately by an additional 90 minutes in the dark (“transient dark”). Standardized growth measurements in each light– dark condition were obtained for 103 genes. The complete data set is saved in the GENES file. Data on the first 10 genes are shown in the following table.