1. Chapter 13 Genetic Engineering

2. Changing the Living World
1. Selective Breeding: 
Selective breeding allowing only the organisms with desired traits to breed
Takes advantage of naturally occurring variation
Ex: domestic dogs, cats, farm animals, most crops

3. Cont. Selective Breeding
Hybridization crossing dissimilar individuals & bringing together the best of both organisms
Hybrids usually hardier than either of the parents
Ex: crossing disease resistance with food production
Inbreeding continued breeding of individuals with similar characteristics
Increased risk of genetic defects
Ex: maintaining characteristics in breeds of dogs

4. Ever wondered what a human-dog hybrid would look like?!?!

5. Human-Dog hybrid was a sculpture created by an Australian artist named Patricia Piccinini.

6. Increasing Variation
Breeders increase variation by inducing mutations (*** ultimate source of variation) 
New kinds of bacteria produced by treating them with chemicals and radiation
- Results: bacteria that can digest oil used to clean up oil spills

7. Cont. Increasing Variation
New kinds of plants produced by treating them with drugs that prevent chromosome separation during meiosis
- Results: polyploidy cells plants larger and stronger (LETHAL in animals!)

8. Manipulating DNA
Genetic engineering making changes in the DNA code of an organism
1. The Tools of Molecular Biology
a. DNA extraction open cells and separate DNA from other cell parts
b. Cutting DNA via restriction enzymes cut DNA into smaller pieces at a specific sequence of nucleotides
c. Separating DNA via gel electrophoresis mixture of DNA fragments are put in one end of porous gel and an electric voltage is applied
- DNA is negatively charged so the fragments begin to travel toward the positive end of the gel
- The smaller the fragment, the faster it travels; the larger/slower

9. Cutting DNA
Recombinant DNA is DNA taken from two different sources and fused into a single DNA molecule. Special DNA cutting enzymes, called restriction enzymes, cut the DNA at specific sites. Each restriction enzyme recognizes a different nucleotide sequence. DNA that is cut with a restriction enzyme will have single-stranded ends, called “sticky ends”. Two molecules of DNA cut with the same restriction enzyme will have the same exposed nucleotides and will undergo complementary base pairing.

10. Gel Electropheresis

11. Electrophoresis

12. Cont. Manipulating DNA 2. Using the DNA Sequence
a. Reading the sequence use fluorescent dyes to identify specific bases and DNA sequences
b. Cutting and pasting via recombinant DNA use restriction enzymes to “cut” a gene form one organism and using special enzymes (ligase) “paste” it into the DNA of another organism
c. Making copies via polymerase chain reaction (PCR) produces multiple copies of DNA strand

13. Cell Transformation
1. Transformation process in which bacteria or some other organism takes in DNA from its environment and incorporates it into its own DNA
  a. Transforming Bacteria
Plasmids small circular pieces of DNA useful for DNA transfer for 2 reasons:
1. Bacterial origin of replication
2. Genetic marker a gene that makes it possible to identify the transformed bacteria
Ex: genes for resistance to antibiotics

15. Cont. Transformation b. Transforming Plant Cells
Infect plant cells with recombinant plasmid whose tumor producing gene has been inactivated
c. Transforming Animal Cells
Inject DNA directing into the nucleus of an egg cell, foreign DNA is inserted into the chromosome

16. Applications of Genetic Engineering
 1. Transgenic Organisms contain genes from other organisms
a. Transgenic Microorganisms
Bacteria transformed with human genes for insulin, growth hormone, clotting favors etc. produce human products
b. Transgenic Animals
Mice with human immune systems are used to study effects of disease
Livestock with extra copies of growth hormone to produce faster growth and less fatty meat
c. Transgenic Plants
Genetically modified food (GM) 52% of soy beans and 25% corn
Plants contain genes that produce natural insecticide or weed resistance

17. Transgenic Animal: Belgian Blue Cattle

18. Cloning
1. Clone member of a population of genetically identical cells produced from a single cell  
Steps:
1. Nucleus of egg cell removed
2. Donor nucleus fused with egg cell using an electric shock
3. Fused cell begins to divide
4. Embryo placed in uterus of foster mother

19. Dolly’s Bonnie