Genetic Engineering

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Genetic Engineering

• Bioethics

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What is Genetic Engineering?

• basic definition genetic engineering is the
  direct manipulation of an organism's genes. 
• Genetic Engineering is useful in many fields
  including food production and medicine.
• While it seems promising, there is still a lot
  that we do not know about Genetic Engineering.

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Gregor Mendel

• Gregor Mendel lived from 1822-1884 in Brunn,
  Austria.
• He was an Augustinian Monk who taught natural
  science to high school students.

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The Father of Genetics

• Mendel was the first person to trace the
  characteristics of successive generations of
  living things.
• Mendel wondered how plants acquired atypical
  characteristics.
• Mendel performed experiments on pea plants, mice
  and ornamental plants.

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Dominance and segregation of traits

• Mendel crossed peas and mice of different
  varieties.
• Through this experiment Mendel discovered the
  phenomena of dominance and segregation.
• Dominance decides which characteristic most often
  surfaces the dominant characteristic overrides
  the recessive gene and appears in the organism.
• Segregation of genes decides which genes are
  inherited from the parents.

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Laws of Heredity

• Heredity factors do not combine they are passed
  intact
• Ex A child of parents with black and red hair
  would inherit one of the two colors not a mix of
  the two.
• Each member of the parental generation transmits
  half of its hereditary factors to each offspring
• Different sets of offspring from the same parents
  receive different sets of hereditary factors
• Ex siblings are not identical, their differences
  come from the inheritance of different genes from
  their parents.

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DNA

• Discovered in 1869
• James Watson and Francis Crick discovered that
  DNA had a double Helix form.
• Our DNA or genes decide who we are, they decide
  everything from our eye color to our shoe size.

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DNA Engineering

• We use recombinant DNA to manipulate genes.
• Recombinant DNA is taking DNA from one source and
  inserting into another organisms DNA giving that
  being those characteristics.
• Ex. Inserting salmons anti-freezing genes into
  corn to allow it to survive frost.

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Process of DNA Engineering

• 1. Restriction enzymes cut DNA at their base
  parts causing sticky ends to form.
• 2. DNA ligase (linker sequences of DNA) are
  placed on the sticky ends of the DNA.
• 3. A Plasmid holding foreign DNA is inserted into
  the DNA and is connected by the ligase. (sticky
  end to sticky end)
• 4. The recombinant DNA is inserted into a
  bacterium which carries out its function inside
  the larger organism.
• 5. When the DNA becomes active it directs the
  body to construct distinct proteins which carry
  out the genes function.

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Examples of Genetic Engineering
Spider Silk

• Creation of artificial spider silk by Nexia, a
  biotech company
• Spider silk protein created by goats in their
  milk, then spun into silk
• However, still not comparable to actual
  spidersilk

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Insulin

• Insulinoriginally isolated from cows and pigs
• 1982 Humulin, a biosynthetic human insulin
• Attempting to optimize insulin production by
  expressing them in different things
• Insert human insulin gene into bacteria

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Penicillin

• Directed evolution of penicillin strains
• Inserted genes to make erythromycin (penicillin
  substitute) into E Coli, which totally worked

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Why do weGenetically 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.
• 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.
• 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. Because the techniques
  used to transfer genes have a low success rate,
  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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Genetic Engineered Foods Fears

• "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)
• 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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Genetic Engineer Foods
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 on non modified potatoes
• While the implications of this study are
  alarming, the study had a number of holes and its
  results cannot be taken to reflect for Genetic
  Engineering.

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Genetic Engineered Foods
Official Word on 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 alleviating 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.
• 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.9

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Medical uses of Genetic Engineering 2

• 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.
• Ex Stem cells since they are so versatile they
  can be created into cardiac tissue, spinal tissue
  and maybe even 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?

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What is Synthetic Biology

• Foundational Ideas
• Automated DNA Construction
• Standards of Abstraction
• Goals
• Organization of genetic information
• Registry of Standard Parts
• Built up through iGEM
• Open-source biological programming language
• Scalable engineering framework

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Abstraction
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Banana Biobrick
Transcription terminator for the E.coli RNA
polymerase
Ribosome binding site
Promoter (lacI regulated)
T1 from E. coli rrnB
alcohol acetyltransferase I converts isoamyl
alcohol to isoamyl acetate (banana odor)
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Past projects

• Synthetic blood
• Banana E. coli
• Arsenic biosensor
• HIV Virotrap
• Self-organized pattern formation