1. Genetic Engineering, Stem Cells, and Cloning

2. Genetic Engineering
Involves changing an organism’s DNA to give it new traits.
Uses recombinant DNA.

3. Recombinant DNA Foreign DNA is inserted Enzymes are used to
(bacterial DNA)
Foreign DNA is inserted
Enzymes are used to
cut a segment of DNA from one organism
Join DNA to a DNA strand in another organism (often bacteria)
Vectors
Viruses
Scientists insert DNA to virus
virus “infects” bacteria with new DNA

4. Transgenic Organisms
Have one or more genes from another organism inserted into the genome.
Transgenic bacteria can be used to produce human proteins (ex: insulin).
Transgenic plants are common in agriculture (ex: fish gene in tomatoes).

5. How gene therapy works: http://www.youtube.com/watch?v=bLI1Gfb0ynw
Replaces defective or missing genes, or adds new genes, to treat a disease.
How it’s done:
genetically engineered viruses with desirable genes
Virus is used to “infect” patient’s cells with genes that carry needed information
Ex: Insert gene to make missing enzyme
insert “suicide” genes into cancer cells

6. Gene Therapy Challenges
Viruses may not insert gene in correct cells
Virus may insert gene in the wrong location
Inserted gene may not be expressed
May trigger uncontrolled cell growth (cancer)

8. Stem Cells Unspecialized cells, can become any type of cell. Types:
Embryonic:
From embryo, controversial
Somatic (adult):
From somatic cells, no controversy
Uses:
Test new drugs
Treat disease
Transplant tissues/organs
Ex: spinal cord injury, stroke, burns, diabetes, arthritis, heart disease
(embryonic)
(somatic)

9. Cloning
A genetically identical copy of a gene or any portion of an organism

10. Cloning in Nature bacteria (binary fission) some plants (from roots)
some simple animals (budding, regeneration)
Twins
(hydra)

11. Somatic Cell Nuclear Transfer
Nucleus is removed from an egg cell
Nucleus of a somatic cell from the animal to be cloned is implanted in the egg.
Used to produce whole organism or stem cells
SCNT:

12. Reproductive Cloning
Produces an animal that has identical DNA to another animal.
Uses
Mass produce animals with special qualities
Repopulate endangered or extinct animals
Controversy
Decreased biodiversity
Very low success rate
clones “imperfect”, often have significant health problems.
(cloning)

13. Therapeutic Cloning
Uses embryonic stem cells to study human development and (someday) treat disease.
Uses
Create cells, tissues, or organs for transplant
Controversy
Use of embryonic cells (when does life begin?)