GMOD: Identifying Genetically

Modified Organisms in Food

Are we eating genetically altered foods?

Objectives

• To identify the presence of genetically modified organisms (GMOS) in foods purchased from the shelves of local grocery stores.

• To discuss ethical issues associated with GMOs and their use in food.

What are GMOs?• GMOGMO= Genetically Modified Organism

• GMOs contain genetic material (DNA) that has been alteredaltered or modifiedmodified through a method that does not occur in nature.

• Often the modification is designed to introduce a new or altered characteristic to the modified organism.

• GMOs are becoming increasingly common among agriculturally important plantsagriculturally important plants.

Why have GMOs been developed?

• With the current technology of incorporating DNA from one organism into another organism, new breeds can be developed faster with new, advantageous traits, such as insect insect resistanceresistance, drought tolerancedrought tolerance or the ability to produce fruit in colder ability to produce fruit in colder climatesclimates.

Examples of GMOsBt Cotton

• Bt cotton planted from 1996 to 1998 is estimated to have yielded 5% more.

• Bt cotton requires less foliar spray than acres with no Bt cotton

• Use of Bt cotton has significantly decreased the cost of insecticides

Examples of GMOsRoundup® Ready Crops

• Yield increases in some crops, due to a better crop safety and less weed competition.

• Efficient control of tough weeds

• Competitive, cost-effective weed control programs

Supporters of GMO

• Supporters of genetic modification argue that the genetic changes improve the nutrient contentnutrient content, handling conditionshandling conditions or hardiness of the foodhardiness of the food and will result in higher yieldshigher yields to increase the availability of food to meet the demands of growing world population.

Controversy over GMOs

A number of concerns

have been raised

regarding genetically

modified foods. These

include worries about

the safety of humanhuman

healthhealth and the health ofhealth of

the environmentthe environment.

Controversial Topics with GMOs

• Some fear that consuming genetically modified foods may expose an individual to proteins that the immune system may not recognize, triggering an allergic reaction.

Could GMOs be responsible for the increase in allergies & automimmune disorders?LOOK AT THESE STATISTICS:

• In the last 20 years, there has been an epidemic increase in allergies, asthma, auto-immune disorders, ADHD, and autism. Today, it is estimated that 20% of American children have allergies, and that there has been a:

• 400% increase in FOOD ALLERGIES

• 300% increase in ASTHMAASTHMA, with a 56% increase in asthma deaths

• 400%400% increase in ADHDADHD

• 1,500 and 6,000% increase in AUTISMAUTISM.

More Controversy• GMOs are present in many products

available on supermarket shelves and produce bins today.

• Yet, many people do not realize they are eating GMOs.

• This is partially because, in the United States, products containing GMOs do not do not need to be labeledneed to be labeled, and those which are made from less than 5% GMOs can be labeled “GMO-free.”

More Controversy continued• Genetically modified crops

become the standard in food production, then developing nations may become heavily dependent upon industrialized nations to supply the majority of the seeds.

• Others question the ethics of consuming animal genes in plant materials and the effect of foreign DNA on animal stress and health.

How are GM plants made?

1. The gene of interest is first placed within a small carrier fragment of DNA called a vector.

2. The vector is introduced into a single plant cell. In the laboratory, the cell is allowed to develop into a fully-grown plant.

3. Under the appropriate conditions, the new gene begins to function, leading to the appearance of the modified trait within the plant.

How are GM plants made?

• Many different genetically modified crops use an identical type of vectoridentical type of vector.

• In our lab activity, we will test different foods to see if they have been genetically modified foods based on detecting this common vector.

• This detection method will be able to identify most forms of GM corn and soybean.

Why test for the presence of GMOs

• The United States and Europe have different policies on labels required for food products containing GMOs.

As mentioned, in the United States, food products containing GMOs are not required to be labeled.

• In Europe, they will not acceptwill not accept an imported crop unless it is 0.9% GM or less.

Why test for the presence of GMOs

In other countries, such as Mexico, GMOs are prohibited as a means of protecting the country’s agricultural heritage. As such, it is important to the farmer, the importer and the exporter to be able to test crops to determine whether they do or do not contain GMOs.

How will we test for the presence of GMOs?

• There are 2 common ways in which the presence of GM crops is currently detected.

• ELISA (Enzyme Linked ImmunoSorbent Assay).

• The other is based on a process called PCR (Polymerase Chain Reaction)

This is what we will use in LAB!!This is what we will use in LAB!!

PCRPCR- Polymerase Chain Rxn• PCR is laboratory version

of DNA replicationDNA replication.

• A special machine called a thermal cyclerthermal cycler makes this technology possible.

• PCR is often referred to

as a “molecular copy molecular copy machinemachine.”

What are we looking for?• After isolating DNA from samples of food,

you will use PCR to amplify two genesamplify two genes.

• The first gene, known as NPTIINPTII, is part of the vector used to create many GMOs.

• The second gene is a 16S16S ribosomal gene associated with plant chloroplast DNA. Because this gene is present in all plants, it serves as a control to see if your DNA extraction and PCR processes were successful.

How do we determine if our food is a GMO?• The amplified PCR

products will be separated and visualized through gel gel electrophoresis. electrophoresis.

• Analyze the gel for the presence of the NPTII NPTII genegene and the 16S 16S ribosomal marker.ribosomal marker. If both show up, then your product does in fact contain GM food crops.