Fish that glow: Dr. Zhiyuan Gong and his colleagues at the National University of Singapore worked with a gene called green fluorescent protein GFP in 1999. This gene was originally extracted from a jellyfish that naturally produced bright green bioluminescence. They inserted the gene into a zebrafish embryo, allowing it to integrate into the zebrafish's genome. This caused the fish to be brightly fluorescent under natural white light and ultraviolet light.