Researchers at the University of Exeter have created a transgenic zebrafish which produces highly targeted green fluorescent signals when exposed to environmental estrogens.

By making the affected parts of the ever-useful fish glow green, the research makes it easier than ever before to see which have been exposed, as well as gauge how the health of the fish has been affected. The research indicates that the estrogens can affect more body systems had been previously thought.

The research team created a genetically engineered biosensor using so-called estrogen responsive elements (or EREs) which in turn trigger green fluorescent proteins (GFPs) which exist naturally in jellyfish, and have previously been applied to zebrafish for pollution-detection purposes, though later also sold as pets under the GloFish trademark.

In addition to the potential disruption to the fish's reproductive system, the latest research induced "specific GFP expressions" in various tissues, organs and body systems when exposed to endocrine disrupting chemicals. Parts of the zebrafish affected include the heart, liver, skeletal muscle, otic vesicle (part of the internal ear), the movement-detecting lateral line, and parts of the brain and nervous system. Most of these had never previously been identified as estrogen targets.

The research time asserts that they have developed "a powerful new model" for understanding the effects and health implications of toxins on vertebrates.

The team's research, entitled Biosensor Zebrafish Provide New Insights into Potential Health Effects of Environmental Estrogens, was published recently in the journal Environmental Health Perspectives.

Source: Environmental Health Perspectives