1. Genetic Engineering

2. Selective Breeding: Breeding Plants and Animals for the Benefit of Humans
Selective Breeding: Selecting individuals with desired traits to produce offspring for the next generation
Used to produce most crops (corn, wheat…)
Used to produce all breeds of domestic animals – dogs, horses, cats, sheep, cattle
Also called artificial selection

3. developed over 800 varieties of plants.
All of the different plants produced from wild mustard by selective breeding!
Luther Burbank
( )
developed over 800 varieties of plants.

4. A. Limits of Selective Breeding
It can be a slow process, taking lots of time and many generations to get the traits that you want.
Can not mix traits from two different species
Can result in undesirable offspring or traits
Example: Might want plants that are drought resistant; however, end up with drought resistant plants that don’t produce many seeds!

5. B. Two Types of Selective Breeding:
1. Inbreeding: crossing two individuals with similar traits.
Advantages:
Desired trait is enhanced and preserved through many generations
Disadvantages:
Decreases genetic variation which could lead to vulnerability to disease
Homozygous recessive traits that are unwanted or unhealthy are more likely to show up.

6. This entire crop was wiped out in weeks by one disease!
Disadvantages of Inbreeding
Because of the loss of genetic variation within this crop, all were equally vulnerable to disease.
This entire crop was wiped out in weeks by one disease!

7. 2. Hybridization:
2. Hybridization: crossing 2 dissimilar, but related organisms
Offspring called hybrids
Advantages:
Usually stronger/hardier than parents –
known as hybrid vigor
Disadvantages:
May promote the loss of native species if released into the wild.

8. Hybridization Examples
1. African catfish (left) grows faster than Thai catfish.
2. Thai catfish (middle) has better tasting flesh than African catfish.
3. Hybrid (right) grows fast & has good tasting flesh.
Problem: It has been released into rivers of Thailand and is disrupting food chains.

9. Other hybrids: The horse and donkey are mated to produce a mule
Other hybrids: The horse and donkey are mated to produce a mule. The lion and tiger are bred to produce a Liger or Tigon. The horse and zebra are mated to produce a zorse

10. II. Genetic engineering: Changing an organism’s DNA to make it more beneficial to humans

11. Genetic Engineering, cont.
Recombinant DNA: DNA made from two separate species
A gene from one organism is “recombined” with another organisms DNA.
Transgenic Organism: any organism that contains recombinant DNA.
These new gene combinations could never be possible in nature

12. Researchers isolate a gene from an organism that has the trait they want to give to a plant.
and cells are grown
1.Transgenic Plants

13. Just for Fun?- a glowing tobacco plant

14. What’s Next on Your Plate?
What’s Next on Your Plate?
What genes do we want them to have?
Insect, Herbicide, and Fungal resistance
Drought resistance
Product quality
New vitamins or other nutritional benefits
Longer Shelf Life (Flavr Savr Tomato)

15. Transgenic Organisms: Plants
Example: Rice plants and daffodils can not
cross pollinate with each other in nature.
The rice on the right is called Golden Rice. Its genome contains the gene for producing vitamin A from daffodils.
This rice is healthier for people who do not get enough vitamin A in their diets.

16. Transgenic Organisms: Animals
Animals are now being produced with genes that increase milk production and muscle mass (meat). Problem: unhealthy; legs cannot support weight

17. Transgenic Organisms: Animals
Genetically engineered mice used in cancer research:
Contain gene from glowing jellyfish
Glow when a cancer is growing in them
Mice are given chemotherapy drugs; if the tumor shrinks, they glow less & less
Mice don’t die from the cancer or the chemotherapy drugs
Mice expressing “glow” gene from jellyfish.
Glowing jellyfish

18. 3. Transgenic Organisms: Bacteria
Used to produce important medicines:
Insulin for diabetics
Human growth hormone (HGH) to treat pituitary dwarfism
Anticoagulants for (for treating heart attack patients)
Bacteria cultures
Insulin

19. Other Uses for Transgenic Bacteria
What’s Next?
The artificial sweetener in most diet sodas phenylalanine is already being made by transgenic bacteria.
How about making a transgenic bacteria that when introduced to the mouth, prevents cavities?
What about transgenic bacteria able to clean up oil spills?

20. Dangers of Transgenic Organisms
Ethical problem (should we)
Transgenic bacteria could be used to create biological weapons
Insertion of gene may interfere with workings of other genes causing disease
A superior transgenic organism that escaped into the environment may damage the ecosystem (food chains)

21. Human Genome Project A genome is an organism’s complete set of DNA
Project began in 1990; Completed in 2003
Coordinated by National Institutes of Health (NIH) & U.S. Department of Energy (DOE)

22. What is the Human Genome Project (HGP)?
Goals of HGP
Reading and determining the sequence of the 3 billion base pairs in the human genome.
Locating and identifying all genes in the human genome which there is about 30,000
Storing information into databases that are accessible to the public
Analyzing and addressing ethical, legal, & social issues involved in using this information

23. Benefits of the Human Genome Project
We have located many diseased genes and genetic tests have been created.
Researching bacteria genomes furthered research for fuel & environmental clean-up
Improved technology for DNA forensic science
Other sequences completed for E. coli, yeast, simple round worm, fruit fly, rat & chimpanzee (model organisms for studying how similar genes work in humans.)
Maps of chromosomes # 13 & # 17; show the location of BRCA 2 & BRCA 1 – breast cancer genes.

24. DNA Fingerprinting/Electrophoresis
DNA fingerprinting: tool used by forensics scientists to identify a person using DNA.
How it Works:
A sample of the person’s DNA is taken from blood, semen, bone, or hair.
DNA fragments are cut – Restriction enzymes cut DNA at specific sequences. Useful to divide DNA into manageable fragments.

25. Electrophoresis DNA fragments are separated based on size and charge.
Phosphate groups are negatively charged
DNA is placed into a gel & connected to an electric current
DNA moves through the gel toward + pole; shortest lengths move the fastest & longest lengths move the slowest.
A characteristic banding pattern is produced and a photograph is taken
The banding pattern is unique for each person – thus called a DNA fingerprint

26. Electrophoresis

27. Electrophoresis

28. Was any of the victims blood on the defendants clothing?
DNA Fingerprints
Used as
evidence in
court cases
Was any of the victims blood on the defendants clothing?
Which dog was probably the culprit (dog that bit the person)?

29. How Cloning Occurs in Nature
1. Clone: an organism that is genetically identical to another organism
All of the genes are the same (identical)
2. Examples of cloning that occurs in nature
Reproduction in bacteria & sponges (asexual)
Identical twins are natural clones

30. Bacteria and Plant Cloning is Easy
Cloning of transgenic bacteria creates many “living factories” used to make insulin & other drugs
2. Cloning of transgenic plants to insure genetics are intact for the next generation.
Bacteria that contain genes for digesting oil can be used to clean up oil spills.

31. Animal Cloning is difficult and controversial
Dolly: First cloned animal
Also called Reproductive Cloning

32. First Cloned Cat

33. What are Stem Cells & Why Do Scientists Want Them?
Stem cells: (link) undefined cells that reproduce continuously & can develop into any type of cells or tissues
2. The hope is to be able to produce tissue & organs for transplants
Stem cell technology can help those who wait for organ transplants.

34. Where do we get Stem Cells?
Embryonic Stem cells are most easily obtained from embryos and umbilical cords. (work best) They are pluripotent.
Adult Stem cells are found in bone marrow and skin.