Genetically Modified Organisms: Recombinant DNA
Technology and its Potential Impact on Society
Milana Sapozhnikov, Claudia Zmijewski, Lawrence Markel, Daniel Aksenov
Professor Jennifer Adams
Macaulay Honors Seminar 3: Science and Technology in New York City
Abstract:
The purpose of our Citizen Science project was to teach high school students the basic
facts about genetically modified organisms so that they could take a stance, or at least consider a
side, on the GMO debate. The learning strands that were addressed in our Citizen Science project
were Strands 1, 2, and 3—sparking interest and excitement, understanding scientific content and
knowledge, and engaging in scientific reasoning. Although we included a substantial amount of
scientific background on genetically modified organisms, the main focus of our project was the
controversial GMO debate. Our final digital deliverable was in the form of a documentary, which
was split between the hard science behind what genetically modified organisms are as well as
how they are made and the pros and cons of GMOs. Our Citizen Science project was ultimately
successful because we were able to have a productive discussion on whether or not GMOs
should be considered a serious threat or a viable solution.
Introduction:
Genetic engineering is a dynamic field of biotechnology in which DNA is transferred
from one organism to another organism to produce a genetically modified organism (GMO).
These genetically modified organisms contain recombinant DNA, which is foreign DNA that has
been incorporated into their own genetic information, and they are therefore termed transgenic.
The field of genetic engineering has been rapidly growing because of the extensive uses for
GMOs in our everyday lives.
Genetically modified organisms are used primarily in agriculture to improve pest
resistance, herbicide tolerance, disease resistance, cold tolerance, drought/salinity tolerance, and
improve nutrition in food crops. Animals have also been genetically engineered to increase their
yield and increase their disease tolerance. Salmon is an example of a commonly genetically
modified organism engineered to enhance their size and speed up their process of maturity.
Cattle have also been genetically engineered to promote their resistance to mad cow disease. But
many ethical questions are also raised with the creation of genetically modified organisms.
Potential environmental hazards such as unintended harm to other organisms, reduced
effectiveness of certain pesticides, and accidental gene transfer to non-target species must be
taken into account in the debate. Possible human health risks such as allergenicity and unknown
implications need to be considered as well.
As the field of genetic engineering has been expanding, it is essential to be aware of the
implications and advantages of creating these organisms. As the public becomes more aware of
the issue, they will better be able to formulate decisions what products to purchase and consume.
Labeling of genetically modified foods has come into major question in politics, as the debate as
to whether it is necessary to label these genetically altered foods should be required by law
intensifies. Learning the science behind gene technology can provide insight into the ethics of
the debate, and provide important knowledge about this growing field.
Materials and Methods:
The process of creating a genetically modified organism involves three main
components: a gene of interest, a target species, a vector, and restriction enzymes. A gene of
interest is a DNA sequence that contains the piece of genetic information desired for insertion. A
target species is the organism that this piece of foreign DNA is inserted into. A vector is a way of
carrying the gene of interest into the target species. A common vector that is used in
biotechnology is a plasmid, which is a small extra chromosome of DNA that is found in bacteria.
Restriction enzymes help in cutting out the gene of interest to isolate it from the original
organism and incorporate it into the vector. Restriction enzymes recognize specific DNA
sequences and cut at these specific places, which are termed restriction sites. Genetic engineering
relies on these enzymes to cut the DNA molecules consistently at these precise points. The same
restriction enzyme is used to cut the gene of interest out of the original organism and is also used
to cut open the plasmid into which the gene of interest is to be inserted. Using the same
restriction enzyme, allows for the creation of the same restriction fragments because the
restriction enzyme cuts between the same exact base pairs in all instances. Therefore the
restriction fragments of the DNA from the plasmid and from the gene of interest can be later
joined together. The most useful type of cleavage that restriction enzymes do is the creation of
sticky ends, which are single-stranded ends that are formed by a staggered cut. The short
extensions of these sticky ends can hydrogen bond with other complementary sticky ends that
have been cut with the same restriction enzyme. This is what happens in genetic recombination
as these ends are joined together by hydrogen bonds and then permanently connected together by
the enzyme DNA ligase. The DNA ligase creates covalent bonds that close the sugar-phosphate
DNA backbone that the restriction enzyme previously cut. This connects the genetic information
from the two different sources and therefore the gene of interest is inserted into the plasmid
vector. This vector is then incorporated into the target species. The process of inserting a vector
into a target species is termed transformation for bacteria (or transduction if using a viral vector)
and termed transfection for eukaryotes.
Discussion:
While biotechnology has been rapidly expanding, the controversy behind the creation of
genetically modified organisms has been growing as well. Proponents of GMOs stress the
potential gene technology has in ensuring an adequate food supply for the increasing population
of the world. On the other hand, opponents of genetic engineering stress the ethical issues behind
the technology.
One advantage of GMOs is that they can be insecticide and herbicide resistant. Insects
have been a major cause of crop losses in farming recently and many funds are allocated yearly
for chemical pesticides to try to combat the issue. Most people do not wish to consume products
that have been treated with pesticides despite the advantages posed from the reduction in crop
loss due to the extermination of the parasitic insects, especially since these pesticides are
potentially hazardous to the environment. Several foods are also genetically modified to be
tolerant against herbicides, the chemicals that are used to exterminate weeds. Although herbicide
resistance is a key advantage when it comes to agricultural management and production, some
people are still hesitant to consume foods that have been treated with any type of chemical. The
widespread acceptance of GMOs would negate the problems that arise from consuming pesticide
treated food.
Other advantages of GMOs include giving organisms more desirable traits, higher food
quality/taste, and more food production. Organisms can be genetically engineered so that they
display new and better traits; for example, farmers have selectively bred corn over thousands of
years so that corn would have bigger kernels. Introducing a more desirable trait through the
process of genetic engineering can be compared to selective breeding, except that genetic
engineering directly changes an organism’s genome while selective breeding simply alters an
organism’s expressed phenotype. But the ultimate outcome of both processes is the same. Recent
research has also shown that genetically modified organisms taste better than their non-GMO
counterparts, another potential benefit of introducing genetically modified organisms to the food
market. GMOs have also been found to increase crop yield while still using the same amount of
land, and in a world where the global population is expected to rise as high as 9 billion in the
next few years, this could prove to be an extremely useful advantage.
On the other side of the GMO debate are the ethical concerns. If certain GMO containing
foods are meant to kill off pesticides, one can imagine what kind of health affects these
pesticides can cause to humans when they digest the foods. Another ethical concern is this role
of playing god with certain aspects of nature. If certain foods where not meant to grow in nature,
why are modern technologies making crops grow in previously inhospitable environments.
Allergies from these GMO-containing foods also play a huge concern and because no long term
effects of GMO’s have been conclusive due to the relativeness newness of GMO-containing
foods.
Our final digital deliverable was in the form of a 10-minute documentary. We tried to
make our documentary as interactive and fun as possible, so we began our video with a popular
contemporary song (Can’t Hold Us by Macklemore and Ryan Lewis) as well as a few quick
shots of GMO examples (apples, cows, golden rice, etc) that our intended audience might be
familiar with. The purpose of the lively introduction was to entertain the audience and cater to
the first learning strand—sparking interest and excitement. The next portion of our documentary
focused on the basic science behind genetically modified organisms, such as the definition of a
GMO, how GMOs are made, and a little bit of basic biology about the central dogma of biology
(DNARNAprotein). This is where we wanted to incorporate the second learning strand, or
understanding scientific content and knowledge. We tried to include the first learning strand
again in the middle of our video so that we wouldn’t lose our audience’s attention, so we
included a picture of a small kitty that was genetically engineered to glow in the dark through the
modification methods that we had just showed in the video.
Next, we further discussed the exact ways in which the genetic code for a specific
desirable trait was taken out of the cells of one organism and physically inserted into the cells of
another organism. Although we did use scientific vocabulary in our documentary, we tried to
introduce each unfamiliar word along with its definition so that if a member of the general
audience wasn’t familiar with high school biology they would still be able to understand how
GMOs were made. For example, we compared restriction enzymes to scissors and also included
a picture of a strand of DNA being cut by a pair of scissors. We also used words like “promoter,”
“terminator,” and “plasmid,” but each time we used these words we made sure to define them in
simple everyday terms. We were essentially taking our in class presentation that we showed to
Mr. Evangelist’s Regents Chemistry class and making it a bit more explanatory so that anyone
could understand the science behind the making of genetically modified organisms. We included
a picture with every single step so that members of the audience could visualize each step as it
was being described in the documentary.
After the detailed step-by-step description of how genetically modified organisms are
made at the molecular level, we again went back to the first learning strand so that the members
of our intended audience wouldn’t lose interest in our documentary after being exposed to a
significant amount of scientific information. However, this time we showed a picture of Glofish,
a type of pet fish that can glow in the dark in six different colors. We thought the picture of the
Glofish would be perfect to show right after the big block of scientific content because it would
ease the atmosphere. We didn’t want our audience to get bored after watching a big portion of
the documentary that was strictly focused on science learning.
The second half of our documentary introduced the pros and cons of genetically modified
organisms. This is where the third learning strand came in—engaging in scientific reasoning. We
wanted our intended audience to take in what they had just learned about genetically modified
organisms and consider it when thinking about the good side and the bad side of the GMO
debate. The documentary showed that the pros of genetically modified organisms included
resistance against disease, resistant against insects, resistance against herbicides, more desirable
traits, higher food quality/taste, and higher food production. It also showed that the cons of
GMOs included the loss of biodiversity, health risks and allergies, as well as the contamination
of other organisms.
The next portion of the second half of our GMO documentary shifted to the video we
took of our presentation at Brooklyn Technical High School in Mr. Evangelist’s Regents
Chemistry class. We recorded a total of 15 minutes when we were presenting to the sophomores,
but we only incorporated about 5 minutes of video into our final documentary. The 5 minutes
that we included were of us talking about the pros and cons of GMOs, with Milana leading the
discussion. We were careful not to take any specific stand on the GMO debate so that our
audience of sophomores could make their own educated decisions and take a stance on the
controversial debate.
Results:
Our citizen science project was held at Brooklyn Technical High School in a Regents
Chemistry class. We decided to bring our PowerPoint and documentary to a class filled with
students that understood the field of GMO and biomedical engineering to a degree so it would be
easier to explain the more difficult points of bioengineering that perhaps the general public
would not easily understand at first.
Our old high school science teacher, Mr. Evangelist, let us take over his class for 15
minutes so that we could present to the classroom and also gave considerable amounts of insight
and information during the class discussion about the pros and cons of GMO’s in foods and
animals. They seemed interested from the beginning that there was a group of college students
who had previously attended the high school coming back to teach something learned from
college.
In the first few slides of our presentation the first learning strand was used to spark
interest by including a catchy song during the slideshow and by using a glow in the dark cat and
mentioning that GMO’s can make this happen. The students seem to enjoy that fact particularly
and began to open their eyes more to the information that was to come. We started off with the
mechanism on how to derive a genetically modified organism from DNA and how the process of
inserting desirable genes into DNA results in a desirable trait being expressed once DNA
replication and translation occurs. Then we broke down the negatives and the positives of
GMO’s and the classroom began taking sides and students started contributing their own
thoughts and opinions. We asked them some possible negative consequences of GMO’s in the
agricultural world and one student brilliantly argued that if GMO’s in corn, for example, offer
pesticide resistance and kill off the bugs that try to eat the crop, wouldn’t it be harmful for
humans to eat the corn as well. This is a very legitimate concern in the field of GMO’s because
the long-term effects are unknown due to this relatively new biotechnological process.
However, we also had comments that ranged into the positive aspect of GMOs such as
possibly ending world hunger because of the ability of genetically modified crops to grow in
conditions that are virtually inhospitable to organically or naturally growing crops. Another
positive effect of GMO’s that was mentioned by another classmate was the fact that nutritional
malnutrition is a serious problem in developing countries and more often than not, nutritionally
rich foods are not available to these communities in adequate quantities. What current
bioengineering technology has allowed us to do is enrich vitamins and minerals to certain foods
such as rice in order to alleviate the nutritional deficiencies in the rice. After looking more into
the student’s classmate, our group found out that scientists at the Swiss Federal Institute of
Technology Institution for Plant Science have created a strain of “golden” rice that contains very
high vitamin A content. We were surprised to see so many people with their own formulated
opinions of the topic before we started to get into the pros and cons that we listed out to present
to the class after the discussion. We did not think that high school students would be so
interested in science, especially when they are exposed to science every day in school. We were
proud with the discussion and the feedback was excellent. Mr. Evangelist emailed us the day
after and told us that after we left, the class still kept talking about GMO’s and that a even bigger
discussion broke out. That is very pleasing to hear because it means that we not only taught them
something but that we sparked interest effectively. Our goals to offer an unbiased lecture on
genetically modified organism were completed beyond expectations. Even we learned some new
and interesting facts from the teacher and from the students. Our presentation in the Macaulay
building will hopefully captivate all the listeners and spark an even bigger discussion. Let’s go,
GMO!
Conclusion:
Our final project presentation was a success. Each member of our group was able to
educate themselves about genetically modified organisms, how they are made, and how they
affect us, as well as use this new information to teach others about genetically modified
organisms. We were able to maintain an unbiased stance on GMOs, so that our intended
audience could make their own informed decision about genetically modified organisms based
on the information they learned from our presentation.