Transgenic organisms

1. Chapter 13
Genetic Engineering

2. Glow in the Dark, oil eating
bacteria; clones; hybrids…say
what??
• Yes, these things are real and possible.
• If you could manipulate DNA, what would you
do?
• What application would it have for society as a
whole?
• What are some of the moral questions that
might arise from your proposed
manipulation?

3. 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

4. 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

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

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

7. 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

9. 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!)

10. 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

11. 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.

13. Gel Electropheresis

14. Electrophoresis

15. 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

16. 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

18. 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 directly into the nucleus of an egg cell,
foreign DNA is inserted into the chromosome

19. 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

20. Transgenic Animal: Belgian Blue Cattle

21. 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

22. Dolly's Bonnie