1. Biotechnology
Genetic Engineering

2. Techniques of the Past
How do you get a plant or animal with certain desirable characteristics?
Selective Breeding: where certain animals or plants are bred in hopes of developing certain traits in offspring
Has been done by farmers for centuries
May not always be successful, could take generations

3. Genetic Engineering
Defined: changing an organism’s DNA to give the organism new traits
Recombinant DNA: DNA made from two or more different organisms
Produces a Genetically Modified Organism (GMO) or transgenic organism

4. Steps in Genetic Engineering
Cutting DNA
Gene of interest is cut by restriction enzymes: bacterial enzymes that recognize and bind to specific short sequences on DNA and cut the DNA between specific nucleotides

5. DNA of a vector is also cut
vector: an agent used to carry the gene of interest into another
cell
:could be a virus, yeast, plasmid (circular DNA from bacteria
that can replicate independently of the main chromosome of
a bacteria)
Restriction Enzyme Animation

6. 2. Making Recombinant DNA
DNA from gene of interest is combined with DNA from the vector (gene splicing)
Recombinant DNA is then
placed in host cell

7. Many copies of the gene are made each time the host cell reproduces
3. Cloning
Many copies of the gene are made each time the host cell reproduces
Produces an identical copy
of the gene as the cell
reproduces
Cell will now produce the
protein coded for by the
introduced gene

8. Genetic Engineering in the Medical Field
Drugs: pharmaceutical companies use bacteria to produce human proteins to help treat certain disease where the body does not produce the required proteins
- ex. Insulin for diabetics, blood clotting factor for hemophiliacs
Vaccines: gene for the disease’s surface protein is inserted into the DNA of a harmless virus. Immune system reacts to the surface protein without any danger of disease infecting the person.
Gene Therapy: inserting healthy genes to replace faulty ones to cure a genetic disorder

9. Genetic Engineering In Agriculture
Genetically Modified Crops: take genes from one organism and splice them into a crop, done to:
- improve resistance of plant to drought, pests, herbicides
(tomato)
- improve nutritional value (rice)
- improve yields (corn, wheat)
- could be used to provide a human vaccine against certain
bacteria (bananas used to vaccinate against dysentery)

10. Genetically Modified Animals:
- use growth hormone produced by bacteria as a supplement to increase milk production
growth hormone has been used to increase the size and weight of pigs and cows
Transgenic animals: insert human genes into the genes of farm animals to get them to produce human proteins in their milk. Proteins are extracted from the milk and sold for pharmaceutical purposes.

11. Concerns Over Genetically Modified Crops
Allergic reactions to gene spliced into a different food
More pesticide resistant weeds if keep spraying same pesticide because it does not affect the crop
Could introduced genes pass from GM crops to their wild relatives?

12. Cloning
Taking the DNA from an adult cell, inserting it into an embryo without a nuclei, implant embryo into mother, gives birth to an organism genetically identical to original adult
Difficult to do successfully because genes are not turned “on” or “off” at the right times during development (process usually takes months in sperm and years in eggs), leads to critical errors in development
Very few cloned offspring survive for very long

13. Genetic Engineering in Forensics
DNA Fingerprint: pattern of dark bands on photographic film, made when DNA is cut by restriction enzymes, stained and separated by size using gel electrophoresis
Is unique for each person
Can be used to establish paternity,
place a person at a crime scene
(DNA is taken from blood, semen,
hair, bone, skin)