Bellringer-December 3, 2013

• Is genetic engineering a new technology (last 25 years)? Around when do think genetic engineering started?

• Have you eaten GMOs?

• What crops do you think have the highest likelihood of being GMOs?

Genetic Modification

Two Methods

• Selective Breeding (breeding plants or animals based on selecting desirable characteristics of the parent)

• Recombinant DNA (genetic engineering) GMO• Genetic Engineers can change the DNA code (genes) of

living organisms.

Natural Selection vs. Artificial Selection

• In artificial selection (selective breeding),

• humans modify other species over many generations by selecting and breeding individuals with desired traits

Selective Breeding

• Breed only those plants or animals with desirable traits

• People have been using selective breeding for thousands of years with farm crops and domesticated animals.

Selective Breeding• The evolution of corn or maize

(Zea mays) involved the gradual increase in the size of the grain head (ear) shown here, as well as the development of varieties that would tolerate the prevailing climatic conditions in different areas of the New World.

How does it work?

In cross pollination (think Mendel’s peas), we are combining two traits to get a mixture of results

In genetic engineering, a single gene, a half page recipe in the 52-thousand-page set of recipe books, can direct the plant to make new traits or remove them

Genetic Engineering- Recombinant DNA

• The ability to combine the DNA of one organism with the DNA of another organism. This is where genes from one species can be introduced into an entirely different species through human intervention.

• An organism that is generated through genetic engineering is considered to be a genetically modified organism (GMO).

• Recombinant DNA technology was first used in the 1970’s with bacteria.

History?• The first GMOs were bacteria in 1973; GM mice

were generated in 1974. Insulin-producing bacteria were commercialized in 1982 and genetically modified food has been sold since 1994. Glofish, the first GMO designed as a pet, was first sold in the United States December in 2003.

Recombinant Bacteria1. Remove bacterial DNA (plasmid).

2. Cut the Bacterial DNA with “restriction enzymes”.

3. Cut the DNA from another organism with the SAME “restriction enzymes”.

4. Combine the cut pieces of DNA together with another enzyme and insert them into bacteria.

5. Reproduce the recombinant bacteria.

6. The foreign genes will be expressed in the bacteria.

How to Create a Genetically Modified Plant

1.Create recombinant bacteria with desired gene.

2. Allow the bacteria to “infect" the plant cells.

3. Desired gene is inserted into plant chromosomes.

Figure 20.2

Bacterium

Bacterialchromosome

Plasmid

Cell containing geneof interest

RecombinantDNA (plasmid)

Gene of interest

DNA ofchromosome

Recombinantbacterium

Protein harvested

Basic research on protein

Gene of interest

Copies of gene

Basic research on gene

Gene for pestresistance inserted into plants

Gene used to alterbacteria for cleaningup toxic waste

Protein dissolvesblood clots in heartattack therapy

Human growth hormone treatsstunted growth

Protein expressedby gene of interest

3• Overview of

gene cloning with a bacterial plasmid, showing various uses of cloned genes

Transgenic

• If genetic material from another species is added to the host, the resulting organism is called transgenic.

• Trangenic organisms are a subset of GMOS. They are a subset of GMOs because they are the species in which their DNA is inserted into another species.

Examples

• For example, taking a gene from a jellyfish and inserting into the zebrafish genome created the “glofish” – fish that glow in the dark which are now being sold on the market.

• Another example is genes from a bacteria inserted into food crops so that the crop can create it’s own insecticide. These plants and animals are also known as “transgenic”.

Desired DNA is

added to an egg cell.

How to Create a Transgenic Animal

The DNA of plants and animals is altered for several reasons

PLANTS1. Disease-resistant 2. Insect-resistant crops3. Hardier and bigger fruit 4. Increased vitamin

content5. “Pharming” purposes

(ex. Vaccine)

70-75% of food in supermarket is genetically modified.

What are Genetically

Modified Foods?

(“Frankenfoods”?)

You have already eaten GM foods. Some GM tomatoes, for example, have had their genes altered to stop them from going soft while they are still growing. For several years they were widely sold in tomato paste.

The GM foods we eat have all been tested for safety. But some people worry about the long term effects of eating genetically modified foods!

What Have I Eaten?

Genetically modified (GM) foods possess specific traits such as tolerance to herbicides or resistance to insects or viruses.

Likely GMO Crops Alfalfa (first planting 2011)

Canola (approx. 90% of U.S. crop)

Corn (approx. 88% of U.S. crop in 2011)

Cotton (approx. 90% of U.S. crop in 2011)

Papaya (most of Hawaiian crop; approximately 988 acres)

Soy (approx. 94% of U.S. crop in 2011)

Sugar Beets (approx. 95% of U.S. crop in 2010)

Zucchini and Yellow Summer Squash (approx. 25,000 acres)

ALSO high-risk: animal products (milk, meat, eggs, honey, etc.) because of contamination in feed. http://www.nongmoproject.org/

learn-more/what-is-gmo/

Can We End World Hunger? Malnutrition and vitamin deficiencies?

Golden rice is genetically modified rice that now contains a large amount of A-vitamins. Or more correctly, the rice contains the element beta-carotene which is converted in the body into Vitamin-A. So when you eat golden rice, you get more vitamin A.

Advantages: •The rice can be considered a particular advantage to poor people in underdeveloped countries. They eat only an extremely limited diet lacking in the essential bodily vitamins. The consequences of this restricted diet causes many people to die or become blind. This is particularly true in areas of Asia, where most of the population live on rice from morning to evening.

Going Bananas? According to recent reports, the world may soon be out of bananas.

Bananas are propagated through asexual cloning, so all bananas are genetically identical

Banana plantations in Africa, Asia and Central America are uniquely susceptible to fungi, viruses and pests.

Unless scientists can find a way to genetically enhance the banana’s ability to ward off parasites, we could be bananaless in ten years.

http://gslc.genetics.utah.edu/features/gmfoods/

Genetically modified organisms are called transgenic organisms.

TRANSGENIC ANIMALS

1. Fish – grow faster than normal aquaculture salmon

2. Chickens – more resistant to infections

3. Cows – increase milk supply and leaner meat

4. Goats, sheep and pigs –

produce human proteins in their milk

Human DNA in a Goat Cell

This goat contains a human gene that codes for a blood clotting agent. The blood clotting agent can be harvested in the goat’s milk..

Transgenic Goat

Transgenic Fish

• AquAdvantage salmon grow twice as fast as wild Atlantic salmon.

• Food and Drug Administration (FDA) is in the final stages of deciding whether to allow GM salmon on to the market.

• Aldi and Whole Foods among retailers refusing to sell product

http://www.nature.com/news/transgenic-fish-wins-us-regulatory-backing-1.12130

Researchers are also working to bring GM cows, chickens and pigs to market.

Are they Safe?

• The GM products that are currently on the international market have all passed risk assessments conducted by national authorities.

• These different assessments include an assessment of environmental and human health risk.

• These assessments are thorough, they have not indicated any risk to human health.

http://www.who.int/foodsafety/publications/biotech/20questions/en/

Is it safe to eat? Why isn't it labeled

in the U.S.? • The U.S. government's position: Genetically engineered crops are safe,

resist disease better, and can provide much-needed food in starving nations.

• The EU position: Keep it out. We prefer organic, which is much healthier. The risk of genetically modified foods to health and the environment outweigh the benefits. Only the multinational biotech companies will benefit, dominating the world food supply and squeezing out traditional farmers.

• The U.S. is the largest producer of genetically modified crops.

'Frankenfood' FearsExperts say this science, like any other, has no

guarantees. Risks include:• Introducing allergens and toxins to food

• Accidental contamination between genetically modified and non-genetically modified foods

• Antibiotic resistance

• Adversely changing the nutrient content of a crop

• Creation of "super" weeds and other environmental risks

Benefits include:• Increased pest and disease resistance

• Drought tolerance

• Increased food supply

 

 

Monsanto• Monsanto Company is a publicly traded American multinational chemical,

and agricultural biotechnology corporation headquartered in Creve Coeur, Missouri.

• It is a leading producer of genetically engineered (GE) seed and of the herbicide glyphosate, which it markets under the Roundup brand.

• Monsanto was among the first to genetically modify a plant cell, along with three academic teams, which was announced in 1983, and was among the first to conduct field trials of genetically modified crops, which it did in 1987

Consumer Attitudes

• Many consumers more readily accept biotechnology as beneficial for their health (e.g. medicines with improved treatment potential).

• In the case of the first GM foods introduced onto the European market, consumers felt the products were of no apparent direct benefit to (not cheaper, no increased shelf-life, no better taste).

• Consumers have questioned the validity of risk assessments, both with regard to consumer health and environmental risks, focusing in particular on long-term effects.

• Other topics for debate by consumer organizations have included allergenicity and antimicrobial resistance.

• Consumer concerns have triggered a discussion on the desirability of labelling GM foods, allowing an informed choice. At the same time, it has proved difficult to detect traces of GMOs in foods: this means that very low concentrations often cannot be detected.

Pros and ConsCrops • Better taste and quality • Less time to ripen.• More nutrients, more food, and stress

tolerance • Improved resistance to disease, pests, and

herbicides • New products and growing techniques Animals • Increased resistance, productivity, hardiness,

and feed efficiency • Better yields of meat, eggs, and milk • Improved animal health and diagnostic

methods Environment • "Friendly" bioherbicides and bioinsecticides • Conservation of soil, water, and energy • Better natural waste management • More efficient processing Society • More food for growing populations

Safety

• Potential human health impact: allergens, transfer of antibiotic resistance markers, unknown effects

• Potential environmental impact: unintended transfer of transgenes through cross-pollination, loss of flora and fauna biodiversity

Access and Intellectual Property

• Domination of world food production by a few companies

• Increasing dependence on Industralized nations by developing countries

Ethics

• Violation of natural organisms' intrinsic values

• Tampering with nature by mixing genes among species

• Objections to consuming animal genes in plants and vice versa

• Stress for animal

Labeling

• Not mandatory in some countries (e.g., U. States)

• Mixing GM crops with non-GM confounds labeling attempts

Bizarre examples

Glow in the darkcats

Venomous Cabbage (scorpion poison)

Exit Slip

1. What the two methods of genetic modification?

2. What are two reasons GMOs are engineered?

3. Name and explain one example of the positive effects of GMOs.

4. Name at least two likely GMO crops.

5. What two areas of risk do the risk assessment assess?