Genetically engineered fish glow
Cape Town - Glowing fish help explain what pollutants do in the body, researchers have found.
Genetically engineered zebrafish help scientists to determine what a range of industrial chemicals do inside the body, National Geographic reported.
The chemicals interact with bodily functions by mimicking the actions of sexual hormones. This results in various reproductive problems in people and animals.
Scientists had no way of effectively tracking the hormonal disturbances created by these chemicals so a team genetically engineered a zebrafish to glow where an endocrine-disrupting chemical is present.
"We've essentially put genetic elements within the fish, over time, that are specifically designed to identify where the chemicals penetrate and act within the body," said study leader Charles Tyler.
He said that the genetic programming does not interfere with the natural body processes, but serves to highlight the chemicals in the body.
"This genetic machinery produces proteins which don't interfere with the way these chemicals act in the body, but they fluoresce green under a fluorescent microscope, providing a reporting system to identify which body tissues are being affected."
So far the technology has been used on young fish because their skin lacks pigment so that researchers can observe the illumination, and the next step would be to breed adult fish without pigment so that the reactions can be observed.
"The next phase is breeding these fish with a strain that lacks pigment in the skin," Tyler said.
The findings are surprising because scientists had assumed that the liver, testes and ovaries were mainly affected.
"It's often been assumed that these chemicals impact the liver or testes or ovaries, but in these fish we've identified them in many different tissues, including parts of the brain," said Tyler.
The data should help identify the thresholds at which the chemicals affect various tissues and organs in the body.