Ever wonder where those neon yellow, green, blue and pink fish came from? You know, the ones that have all the matching accessories: tanks, decorations, rocks and their own special ultraviolet light? Well, as it turns out, a team of scientists in Singapore were the first ones to genetically modify fish to glow in such a way.

Genetic editing in small animals and plants has been around since the 1970s, according to Synthego, a company that provides genetically edited stem cells. Starting with plants and bacteria, scientists began to explore the realm of DNA and genetics. As their understanding of the proteins grew, so did their curiosity.

When scientists learned how to modify the genes of small, simple organisms, they began to wonder, "How could this be applied to humans?"


The scientific community is stirring with the emergence of CRISPR DNA, more specifically known as the CRISPR-Cas9 protein. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. CRISPR is a faster, cheaper and more accurate way of editing the genome, according to the National Institute of Health. By sending in two different pieces of CRISPR DNA, scientists are able to modify genes. To do so, they cut out areas of genes that aren't performing how they should be or as they're expected to.

Dr. Sandi Connelly, a principal lecturer in the Thomas H. Gosnell School of Life Sciences, explained how DNA works and what the CRISPR Cas-9 protein actually does. Connelly compared DNA to a street of houses — each person has different foundations that sprout out different and unique homes.

“CRISPR is a piece of DNA, and we [scientists] attach to it an enzyme ... it cuts the DNA at a very specific place like a pair of scissors,” Connelly said. “When we look at CRISPR, typically we look at CRISPR Cas-9."

Whereas CRISPR is the DNA itself, Cas-9 is the enzyme, a specialized protein that splits the DNA. Connelly said that this allows for both the CRISPR DNA and the original DNA to stick together like magnets. However, due to the specificity of this technique, scientists need to know where in the DNA they're looking.

“Using those same enzymes, we can cut [and] place back in the good gene,” Connelly said.

Now, this technique would not be done by injecting the CRISPR DNA directly into a fully grown adult. Instead, scientists would take a sample of a person’s bone marrow and alter the genes of those cells. Since bone marrow is responsible for producing red blood cells, the new altered bone marrow will produce cells with the new DNA.

Connelly said the changes would not be instantaneous. The human body replaces a majority of its cells within 13 days, so it would take around two weeks for the newly edited gene to be present in the human body.


The ability to now alter genes of more complex organisms brings with it a variety of applications. Plants can be changed to increase nutritional value and pesticidal properties, whereas bacteria can be used to generate hormones and medicines.

Dr. David Holtzman, an adjunct professor in the College of Science, understands how gene editing is used and what it could be used for.

“Most people are familiar with it [gene editing] for things like modifying plants ... [but] there is a lot of misunderstanding about gene editing,” Holtzman said.

“There is a lot of misunderstanding about gene editing.”

CRISPR has begun to work its way into at-home kits, where those with some scientific expertise can genetically modify their own plants to glow or be a different color. This is fairly simple in the world of gene editing as it is changing a simple expressed trait — one that is biologically shown.

Genes decide what traits a person has, but that person’s environment and what happens to their body determines how those traits are expressed. As gene editing becomes more and more innovative, Holtzman said that there are limitations to what gene editing can and cannot do.

“It turns out most traits are more than one gene,” Holtzman said.

Holtzman used hair color as an example. Numerous genes and sections of DNA code for what an individual's hair color will be. It can be hard and time-consuming to find the right area of the DNA to target for modification.

Connelly talked about the idea of changing hair color as well, but took it a few steps further. She suggested that we may start wanting to create offspring that all have blonde hair and blue eyes, which realistically we could accomplish. This then opens parents up to the ideas of having all male children or all female children.


In recent years, science has progressed faster than we could have thought. What appeared to be science fiction in the past is inching ever closer to our scientific reality.

“The ability to do [new] things happens a lot faster than our understanding of what we are doing,” Holtzman said.

Regardless of the potential scientific progress that could be made, Holtzman, Connelly and other members of the scientific community are having conversations about what should be done with this technology. Where should the limits lie, and how far should humans go with genetic technology?

"Where should the limits lie, and how far should humans go with genetic technology?"

If our parents changed our genes, they would also be changing the genes of all of our descendants by extension. Did they consent to something like that?

“Some might argue, whether we gene edit or not, we don’t really have control over what our parents did,” Holtzman said. “There is the possibility that if we changed [certain genes] then we can change them back.”

Reversal isn't a guarantee, though.

Holtzman mentioned ways in which gene editing could greatly improve the quality of life for all humankind, such as curing Alzheimer’s disease. Connelly brought up how easy it would be to reduce the effects of aging using genetic modification.

The consequences of the choices made now may not affect the generation making them. As the movement to improve the genetic composition of the human race pushes forward, plots in sci-fi novels may no longer be abstract, distant futures. Rather, for better or worse, they could be the reality we are setting up for generations to come.