Glowing Fish

Dr. Eric Schroeter's research involved the imaging of fluorescent-labeled cells in zebrafish under the confocal microscope. During the experimental process, Schroeter and his colleagues first searched for a promotor that would drive expression of the fluorescent proteins within the zebrafish retina. The injections took place at the one-cell stage, and the larvae showing particularly high levels of YFP expression were reared to adulthood to create progeny with the same YFP expression. Dr. Schroeter's use of fluorescence inside zebrafish enabled him and his team to better analyze the inner-network of bipolar cells in the retina. The fluorescent proteins indicated location and mobilization of the cells being analyzed, and allowed for a logical conclusion of the development of ON-bipolar cell axonal terminals.

Fluorescent technology has aided researchers in their studies of all areas of biological processes. Environmental biologist Charles Tyler of the University of Exeter recently utilized fluorescent technology in zebrafish, but not just in the retina. Tyler's team genetically engineered zebrafish to glow green throughout the entire body, depending upon the organs' reactions to endocrine disruptors.

Zebrafish glow green under the microscope.

Photographs courtesy University of Exeter

Endocrine disruptors are found in common industrial  products, such as plastics, and also in many females contraceptives. These disruptors could result in reproductive problems, such as lower sperm counts, breast cancer, and testicular cancer. In order to better understand the pathways particular endocrine disruptors take within the body, Tyler generated a way for zebrafish to glow in places affected by an endocrine disruptor. Tyler describes the process as follows:

"We've essentially put genetic elements within the fish [embryos that], over time, that are specifically designed to identify where the chemicals penetrate and act within the body".

Through this process, researchers have an improved way of identifying where in particular the pollutants are having their effects. So far, the glowing zebrafish have confirmed a link between bisphenol A and heart problems. Tyler's research helped confirm previous findings of other researchers, as well as pinpoint new findings. Tyler elaborates that "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".

Fluorescent genetic engineering is a relatively new innovation, but the technology has definitely established itself as a critical component in the study of biological processes. This was made evident in both Dr. Schroeter's research, as well as Tyler's. 

Sources:

Handwerk, Brian. "Fish Glow Green After Genetic Engineering." National Geographic. National Geographic Society, 23 Apr. 2012. Web. 09 Dec. 2012.

Schroeter, Eric H., Rachel Wong, and Ronald G. Gregg. In Vivo Development of Retinal ON-bipolar Cell Axonal Terminals Visualized in Nyx::MYFP Transgenic Zebrafish. Cambridge University Press, 12 May 2006. Web. 9 Dec. 2012.