The world recently got an up-close look at the power — and potential — of DNA editing in a breakthrough experiment that diced and spliced a flower’s genes to change its color.
Scientists harnessed the intricate power of the CRISPR process, a gene-editing technology that taps into the inner workings of genetic material to cut out and stitch together new sections, to change the color of morning glory flowers from violet to white.
The new study, conducted by researchers at the University of Tsukuba in Japan, is the first known experiment to change a flower’s colors by CRISPR-derived gene manipulation.
The technology, which scientists believe holds incredible potential to “switch off” disease-causing genetic mutations, repair harmed DNA and essentially rewrite the book on human evolution, works by tapping into normal DNA activity. For the current study, researchers used an enzyme known as Cas9 to infiltrate select genetic material and revise the flower’s source code.
Cas9 “cuts the two strands of DNA in a precise location so that DNA can be added or removed,” reports the research team. “Cas9 is guided to the correct location by gRNA, or guide RNA, a small piece of RNA that has been designed to be complementary to the target DNA sequence.”
Then, “Cas9 cuts the two strands of DNA at the target location, allowing DNA to be removed and/or added,” the team explains.
In this case, the researchers targeted a single gene, dihydroflavonol-4-reductase-B (DFR-B), which “is responsible for the color of the plant’s stems, leaves and flowers.”
To reach the DFR-B gene, the researchers had to navigate crowded terrain, working on a microscopic level. Directly next to the DFR-B gene sit two other genes, DFR-A and DFR-C, and the key was to disrupt the DFR-B gene without altering the other two.
Threading the Cas9 enzyme to the correct gene successfully destabilized the DFR-B enzyme, which in turn stopped the enzyme associated with the violet pigment from correctly operating. The process was successful in 75 percent of the plants on which the CRISPR method was used.
The researchers also assessed how second-generation plants, derived from those that had their violet enzymes turned off, would appear.
“These plants looked exactly like their parents,” reports the research team. “Among these plants were some without any sign of the introduced DNA.”
The results raise compelling questions about the use and regulation of genetically modified organisms (GMOs), according to the researchers, given that the next generation showed no signs of foreign DNA.
The new study serves as a microcosm of the vast power of the CRISPR technology. According to the researchers, violet morning glory plants were introduced to Japan in the 8th century, and it wasn’t until about eight centuries later, in 1631, that the first white-hued morning glories appeared naturally in the country.
“What took nature nearly 850 years to achieve has taken less than one using the CRISPR/Cas9 system, indicating both its power and its potential,” they report.
Richard Scott is a health care reporter focusing on health policy and public health. Richard keeps tabs on national health trends from his Philadelphia location and is an active member of the Association of Health Care Journalists.