Laurie MetsMolecular Genetics and

Cell BiologyThe University of ChicagoFermi Lab, March 16, 2002

Genetic Engineering and

FoodHow can we understand the impact of science on

what we eat?

Good Food at a Good Price

• Nutritional– Energy (calories)

– Essential nutrients

• Appealing– Flavor

– Appearance

• Not harmful

• Highly productive agriculture

Genetic Engineeringimpacts each of theseproperties of plants

(and animals)

What is “Genetic Engineering?”• “Genetic engineering focuses on the manipulation

(blocking, adding, or scrambling) of the genetic material (the DNA) inside the cells of living organisms to block or add desired traits.” www.wholefoodsmarket.com

• Modification of the genetic makeup of organisms by man– Cross-breeding and progeny selection

• Plant A fertilized with pollen from plant B

– Molecular genetic engineering

• Enabling technology - not intrinsically harmful; not intrinsically beneficial

Genetic Engineering is an Ancient Art

• Darwin – variation is much higher in domesticated species than in wild species

• Braidwood – time and place of domestication can be traced to location of increased variation

• Bruce D. Smith – times and sites of domestication correspond to the origins of organized civilizations

• Variations under domestication represent changes in the genetic composition of the organisms associated with man’s activities

Best Invention of the Millenium - NY Times Magazine, 4/19/99

“How the bean saved civilization”

- Umberto Eco

Prof of Semiotics, Univ. of Bologna

Examples of engineered species

• Wheat (Triticum aestivum) - a man-made species

• Corn (Zea mays) - derived from teosinte• Soybeans (Glycine max) - from G. soja• Potatoes (Solanum tuberosum) - wild

varieties are toxic

None of the food varieties can grow without help from man

The Development of Genetic Engineering Techniques

• Darwin - models for understanding the role of selection

• Mendel - mathematical models for predicting the outcome of cross-breeding

• Beadle (et al) - how genes determine the chemical composition of organisms

• Watson & Crick - general model for DNA structure

• Cohen & Boyer – DNA splicing leads to artificial “transgenic” organisms

Agrobacterium

• A soil bacterium that generates transgenic plants• Transfers some of its genes to the plant• Causes “gall” growths and forces the plant to make

nutrients for it• Use by human molecular genetic engineers:

– genes that the bacterium transfers are replaced by others– e.g. BT toxin for pest resistance; herbicide degrading

enzymes for herbicide resistance; enzymes to alter fatty acid composition or add nutrients (Golden rice)

– Host range has been modified for engineering monocot crops like rice and corn

Virtual Engineering Projects

• What property of an organism would you like to change?

• How might that property be controlled by genes?

• What specific steps must be taken to accomplish the engineering?

• Assessment: what are the social impacts – both intended and unintended?

Molecular anatomy of a gene

Unicellular organism

Multicellular organism

“From Alchemy to Algeny”

“The very thought of recombining living material into an infinite number of new combinations is so extraordinary that the human mind is barely able to grasp the immensity of the transition at hand”Jeremy Rifkin, The Biotech Century

Like the theories underlying alchemy, this analysis is based upon a faulty scientific model.

What can be engineered is limited by physical and genetic realities.

Science provides tools and models

Valuation requires social and political

processes

• What should be genetically engineered?

• Why should it be engineered?

• Who should be involved in the discussion?

• How should the discussion be conducted?

Problem:The pace of change enabled by modern genetic engineering is

outstripping the ability of cultural traditions and institutions to

assist in the evaluation of foods

“Public aceptance of foods [from transgenic plants] ultimately depends on the credibility of the testing and

regulatory process…”

Dr. Perry Adkisson

April 5, 2000

in introducing public release of the National Research Council report on “Genetically Modified Pest-Protected

Plants: Science and Regulation”

How does genetic engineering affect agricultural practice?

• Traditional cross-breeding for commodity markets is a numbers game that will always be dominated by the largest players

• Engineering of added value traits should create specialty niche products, subdividing commodity markets and creating opportunities for smaller scale players

Why is the organic farming industry opposed to “Genetic Engineering?”

• Organic farming accesses a niche market of consumers who want to avoid potential exposure to agricultural chemicals

• Genetic methods that could obviate the use of chemicals in traditional agriculture represent a threat to that niche

From www.wholefoodsmarket.com

“Unintended Consequences of Agricultural Biotechnology”

Antibiotic resistance. The use of antibiotic resistant “marker” genes risks the transfer of antibiotic resistance into humans and the environment, diminishing the effectiveness of the antibiotics.

Antibiotics in common use for marker selection:

G418; Kanamycin

From www.wholefoodsmarket.com

“Unintended Consequences of Agricultural Biotechnology”

Allergies. The effect known as antiidiotope allergen. Cummins in “Genetic Engineered Foods and Allergenicity” states that “When an antibody is made against an antigen (allergen) there is an antibody made against the antibody (antiidiotope antibody). Most genetically engineered crops have genes for antibiotic tolerance, which produce enzymes that match an allergenic antibiotic. The enzymes will produce antibodies that are allergens. Thus most genetically engineered crops are likely to be allergenic to people sensitive to antibiotics.”

Antibiotics in common use for marker selection:

G418; Kanamycin

What lies in the future?

• Modern gene transfer engineering makes smaller, more defined changes than traditional cross-breeding methods

• Genomic approaches to marker-assisted breeding promise to make engineering by cross-breeding more efficient and precise

Direct Physical Mapping ofSingle DNA Molecules

5kb;1700nmLaurie Mets

MGCB

Ed KibblewhiteAstronomy & Astrophysics

David GrierPhilippe Guyot-Sionnest

Heinrich JaegerPhysics

Stu KurtzRidg Scott

Computer Science

Mary Sara McPeekDan Nicolae

Statistics

Norbert SchererChemistry

Raj SinhaBiology, Chicago State

The Biomics Project

Jean GreenbergSusan Lindqust

MGCB

Matthew LeiboldEcology & Evolution

Janet RowleyMedicine

Tag

Tag

Hairpin clamp probes boundto double stranded DNA

Comparative Physical Mapping

Microbial Community Assessmentwith Raj Sinha, Chicago State Univ.

Vancomycin resistant enterococci from produce - lateral transfer or selected strains?

Civilization itself depends upon

genetic engineering

Techniques are becoming more

powerful and technical outcomes more

predictable

Use of engineering requires thought