Why do we Genetically Engineer Foods?

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Why do we Genetically Engineer Foods?

• Biotechnology is needed to feed the growing
  population of the world, especially the Third
  World.
• Reduced chemical inputs, which will be good for
  the environment.
• Genetic Engineering creates better yields in
  foods by giving them
• Pest resistance
• Herbicide tolerance
• Disease resistance
• Cold/drought tolerance
• More nutrition
• Ability to replenish the soil they were grown in.

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Engineered food-process

• Biochemical scissors called restriction enzymes
  are used to cut the strings of DNA in different
  places and select the required genes. These genes
  are usually then inserted into circular pieces of
  DNA found in bacteria. The bacteria reproduce
  rapidly and within a short time thousands of
  identical copies can be made of the new gene.

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• There are now two principal methods that can be
  used to force the new gene into the DNA of the
  plant that is to be engineered. A ferry is made
  with a piece of genetic material taken from a
  virus or a bacterium. This is used to infect the
  plant and in doing so smuggle the new gene into
  the plants own DNA.
• Or, the genes are coated onto large numbers of
  tiny gold pellets which are fired with a special
  gun into a layer of cells taken from the
  recipient organism, with any luck finding a hit
  somewhere in the DNA in the nucleus of the cells.
  

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• Genetically engineered animals and fish are
  produced by microinjection. Fertilized eggs are
  injected with new genes which will, in some
  cases, enter the chromosomes and be incorporated
  into the animals own DNA.
• Techniques used to transfer genes have a low
  success rate, so the scientists need to be able
  to find out which of the cells have taken up the
  new DNA. So, before the gene is transferred, a
  marker gene is attached which codes for
  resistance to an antibiotic.

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Genetically Engineered Foods Fears
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"Human health effects can include higher risks of
toxicity, allergenicity, antibiotic resistance,
immune-suppression and cancer. As for
environmental impacts, the use of genetic
engineering in agriculture could lead to
uncontrolled biological pollution, threatening
numerous microbial, plant and animal species with
extinction, and the potential contamination of
non-genetically engineered life forms with novel
and possibly hazardous genetic material."
(http//www.centerforfoodsafety.org/geneticall7.cf
m)
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Other Possible Problems

• Unintended harm to other organisms
• Reduced effectiveness of pesticides
• Gene transfer to non-target species
• Allergies
• Unknown effects

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• Experiment on rats of the same age. Control group
  on the left. Rat on the right was fed GM-soy.

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Case Study Pusztai Potato Data

• Pusztai reportedly fed rats potatoes genetically
  modified to have snowdrop lectin (which is an
  insecticide). The rats had stunted growth
  immune system damage
• Controversy confusion over the lectin was from
  snowdrop (cool) or jackbean (poisonous).
• research republished in October 1999, reviewed by
  6 reviewers. The paper did not mention stunted
  growth or immunity issues, but reported that rats
  fed on potatoes genetically modified with the
  snowdrop lectin had "thickening in the mucosal
  lining of their colon and their jejunum" when
  compared with rats fed non-modified potatoes.
• While the implications of this study are
  alarming, the study had a number of holes and its
  results cannot be taken as a reflection on
  Genetic Engineering.

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Safety

• GM foods are highly regulated and they must pass
  extensive safety testing before reaching market.
• GM foods have been consumed by hundreds of
  millions of people so far with no reported health
  problems to date.
• Still, it is possible that genetic engineering
  can unintentionally transfer allergens between
  foods. Also Genetic Engineering can create new
  allergens.
• Genetic Engineering has only been around for 15
  years. There are worries that long-term problems
  involving GM foods could be in our future.

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Medical uses of Genetic Engineering

• Pigs are often chosen as transgenic animals
  because their physiology and organ size are so
  similar to humans. The hope is that pig organs
  can be used for organ transplantation, known as
  xenotransplantation.
• This will alleviate the shortage of human hearts
  and kidneys, which are in scarce supply.
• Researchers are also exploring the use of cell
  transplantation therapy for patients with spinal
  cord injury or Parkinsons disease. There are
  several drawbacks to xenotransplantation.

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Medical uses of Genetic Engineering (2)

• Additionally, commercial companies seek to derive
  therapeutic proteins, such as monoclonal
  antibodies, from the milk of transgenic cows,
  goats, rabbits, and mice and use them to
  administer drugs in treatment of rheumatoid
  arthritis, cancer, and other autoimmune
  disorders.
• Other uses of this transgenic combination include
  growing tissue on a scaffolding, or supporting
  framework. This then can be used as a temporary
  skin substitute for healing wounds or burns or as
  replacement cartilage, heart valves,
  cerebrospinal shunts, or even collagen tubes to
  guide re-growth of nerves that have been injured.

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Medical uses of Genetic Engineering (3)

• Scientists harvest stem cells that can be used to
  study human development and to treat disease.
• Stem cells are important to biomedical
  researchers because they can be used to generate
  virtually any type of specialized cell in the
  human body.
• The extraction process destroys the embryo, which
  raises a variety of ethical concerns.
• Stem cells are so versatile that they can be
  modified into cardiac tissue, spinal tissue, and
  possibly nerve tissue.
• Stem cells may be the key to curing diseases
  caused by the erosions of nerves such as
  Alzheimers and ALS.

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Ethical problems

• If the blending of nonhuman animal and human DNA
  results, intentionally or not, in trans-species
  entities possessing degrees of intelligence or
  sentience never before seen in nonhuman animals,
  should these entities be given rights and special
  protections?
• It is possible that in blending DNA of different
  species we might be making our subjects
  susceptible to new forms of disease?
• Could we inadvertently create a super-disease?
• Is it right for parents to genetically alter
  their children before birth?