Biotechnology and Bioinformatics (1+1)

2.2.7. Glofish

The GloFish is a patented brand of genetically modified (GM) fluorescent zebrafish (Danio rerio) with bright red, green, and orange fluorescent color.

Zhiyuan Gong et al. (1999) at the National University of Singapore were working with a gene called green fluorescent protein (GFP), 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, which caused the fish to be brightly fluorescent under both natural white light and ultraviolet light.

• Their goal was to develop a fish that could detect pollution by selectively fluorescing in the presence of environmental toxins . The development of the always fluorescing fish was the first step in this process. Shortly thereafter, his team developed a line of red fluorescent zebra fish by adding a gene from a sea coral, and yellow fluorescent zebra fish, by adding a variant of the jellyfish gene.

• Later, a team of Taiwanese researchers at the National University of Taiwan, headed by Huai-Jen Tsai, succeeded in creating a medaka (rice fish) with a fluorescent green color. Taiwan became the first to authorize sales of a genetically modified organism as a pet.

• In addition to the red fluorescent zebrafish, trademarked as "Starfire Red", Yorktown Technologies released a green fluorescent zebrafish and an orange fluorescent zebrafish in mid-2006.

• The new lines of fish are trademarked as "Electric Green" and "Sunburst Orange", and incorporate genes from sea coral.

• Despite the speculation of aquarium enthusiasts that the eggs are pressure treated to make them infertile, it has been found some GloFish are indeed fertile and will reproduce in a captive environment.

• The original zebrafish (Danio rerio) from which the GloFish was developed is a native of rivers in India and Bangladesh.

• It measures 3 cm long and has gold and dark blue stripes.

• Although not originally developed for the ornamental fish trade, it is the first genetically modified animal to become publicly available as a pet.