Cloning

1 Cloning

A clone is, genetically speaking, an exact duplicate. The DNA of clones is identical.

Laboratory Procedure

Extract nucleus (containing DNA) from egg cell.

Replace with DNA from ``source''

Allow egg cell to grow normally

2 Why Clone?

Pro

Excellent ``controls'' for laboratory experiments

Production of organisms with desirable properties.

Con

Hard

DNA used is ``old'' (adult DNA different than infant DNA)

ethical ?

3 Clones are NOT Identical

National Geographic

4 CopyCat Clone Articles

Time Magazine

National Geographic

CBC News (Canada)

Vet Centric

5 Genetically Modified Foods

This short lecture will discuss various factors relating to genetically modified (GM) foods. (Note that these are also called transgenic foods).

Resources

Procedure - Differences from plant breeding

Potential Benefits

Potential Risks

6 Web Resources

Northern Light Special Edition
The best general resource that I have found, containing links to a large number of sites with information on GM Foods.

Scientific American, April 2001
Only one article is available online. Actual issue contained several different articles dealing with this topic.

PBS ``Harvest of Fear'' Web Site
This site is based on the Nova/Frontline show, first aired April 24, 2001.

7 GM Food Usage

Genetically modified foods are already in use in this country.

``In the U.S., an estimated 60 percent of processed foods in supermarkets - from breakfast cereals to soft drinks - contain a GM ingredient, especially soy, corn or canola; some fresh vegetables are genetically altered as well.'' Scientific American, April 2001, p. 60

``GM ingredients, in the form of modified enzymes, are found in virtually all breads, cheeses, sodas, and beers, and farmers have been raising GM food crops such as corn, soybeans, and potatoes since the mid-1990s.'' ``Harvest of Fear'' Web Site

8 Making GM Foods

The following highly-simplified procedure explains how transgenic materials can be made.

Isolate DNA of interest (produces toxins, antibiotic resistant, ...)

Insert into a bacterium, and allow bacteria to reproduce

Transfer DNA from bacteria to target plant (corn, rice, ...) cells

Remove cells that don't contain new gene

Allow plant cells to grow to maturity

See also Colorado State Univ. site - contains a nice animation of the process.

9 Potential Benefits

Proponents of genetically-modified foods commonly cite the following benefits.

Herbicide Tolerance - If plant resists herbicide, then easier to kill weeds

Insect Resistance - Should reduce reliance on insecticides

Improved Yields - May be possible to grow more, higher nutrition food under poorer growing conditions

10 Potential Risks

Opponents of genetically-modified foods commonly cite the following concerns.

Health Hazard - Very few studies to date. Some do indicate risk.

``A review of existing scientific literature reveals that key experiments on both the environmental risks and benefits are lacking.'' Wolfenbarger, L.L.; Phifer, P.R. Science Dec. 15, 2000, 290, 2088.

Superweeds/Superbugs - Weeds and bugs targets by both traditional and GM toxins adapt.

Unnatural Combinations - What is missing or added? Is it safe? Is it beneficial?

11 Current Products

Soybeans

Corn

Cotton

Canola

Current products focus primarily on insect pest resistance and/or herbicide tolerance.

12 Proposed Future Products

Pest resistant corn, grapes, and trees

Vitamin-enriched foods: Tomatoes, canola oil, rice

Plant-based vaccines

Decaffeinated coffee and tea

Nicotine-free tobacco

File translated from T_EX by T_TH, version 3.02.
On 16 Apr 2002, 10:08.