A technique developed by University of California, San Diego biologists, which uses bright fluorescent dyes to reveal the activity of genes in individual cells of an organism, promises to be a boon to developmental biologists, and may provide new insight into how cancerous tumors begin and grow. The advance, described in the August 6 issue of Science, allows researchers, for the first time, to simultaneously visualize the activity of multiple genes in the same cell. The combination of genes that are active in a particular cell during development determines that cell’s fate—what type of cell it becomes. The advance also makes it possible to quantify how active a gene is, and even infer the genetic makeup of an organism.
