1. Genetic Engineering II

2. Do Now: What was Griffith’s experiment? What was his conclusion?

3. Transformation
Scientists now know the following about Griffith’s experiment:
The heat-killed bacteria must have contained DNA fragments
When he mixed those fragments with live bacteria, a few of them actually took up the DNA molecules
Conclusion: bacteria can be transformed simply by placing them in a solution containing DNA molecules
During transformation, a cell takes in DNA from outside the cell: This external DNA becomes a part of the cell’s DNA

4. Do Now: What is Transformation

5. Transforming Bacteria
Bacteria can be transformed using recombinant DNA: a form of artificial DNA that is created by combining 2 or more sequences that would not normally occur together
Most recombinant DNA involves a small, circular DNA called plasmid
Combine the 2 DNA strands with ligase

6. Plasmid
Plasmids are found naturally in some bacteria and have been very useful for DNA transfer:
Small extra circles of DNA located in the cytoplasm of the bacterial cell
Carry extra genes that bacteria can use
Can be swapped between bacteria
Can be picked up from the environment

7. How can plasmids help us?
It is a way to get genes into bacteria easily:
Insert new gene into plasmid
Insert plasmid into bacteria = vector
Let the bacteria make proteins for that new gene

8. Applications of recombinant DNA and transformation
Copies of Gene
Copies of Protein
Genes for pest resistance
Produce human growth hormones
Basic protein research
Basic gene research
Gene used to alter bacteria to clean up for oil spill
Protein dissolves blood clots in heart attack

9. Application of Genetic Engineering
Transgenic Organisms: Organisms that contain genes from other organism
Transgenic microorganisms: Because they reproduce rapidly and are easy to grow, transgenic bacteria now produce a host of important substances useful for health and industry
e.g. the human forms of proteins such as insulin, growth hormone and clotting factor

10. Application of Genetic Engineering
Transgenic animals: They have been used to study genes and to improve the food supply
e.g. spider goat, glow fish
Transgenic plants: They are now an important part of our food supply
e.g. Many of these plants contain genes that produce a natural insecticide, others have genes that enable then to resist weed killing chemicals

11. Herbicide, pest, and disease resistance: help minimize the invasion of weed species and improve resistance to pests and disease. Improve stress tolerance: enhance tolerance to heat, cold, and drought. Improve product characteristics: bring to market new colors of flowers, long-lasting plants, and low mow grass.

13. Application of Genetic Engineering
Cloning: A clone is a member of a population of genetically identical cells produced from a single cell
Cloned bacteria and other microorganism are easy to grow, but this is not true for animals
In 1997, Scottish scientist Ian Wilmut cloned a sheep named Dolly

14. Dolly News Clip

15. Clone A donor cell is taken from a sheep’s udder
These 2 cells are fused
The nucleus of the egg cell is removed
An egg cell is taken from an adult female sheep
The fused cell begins dividing normally
The embryo is placed in the uterus of a foster mother