Biotechnology Lectures (PowerPoints)

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Today’ s Agenda:
Journal Questions:
(1) Describe what you know about DNA.
(2) What is genetic engineering
(Biotechnology)?

*1. Lecture: Genetic Engineering
(Biotechnology) & Recombinant DNA
Technology -slide …. 80
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Genetically Modified (GM) Crops
around the World
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Genetic
Engineering
Dr. Rick Woodward
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Genetic Engineering
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Genetic Engineering
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Genetically Engineered
Boneless Chicken Ranch
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DNA, the Law, and Many Other
Applications –
The Technology of DNA Fingerprinting
A DNA fingerprint used in a murder case.
The defendant stated that the blood
on his clothing was not his.
What are we looking at? How was it produced?
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DNA Fingerprinting Basics
A. Different individuals carry different alleles.
B. Most alleles useful for DNA fingerprinting
differ on the basis of the number of repetitive
DNA sequences they contain.
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DNA Fingerprinting Basics
A DNA fingerprint is made
by analyzing the sizes of
DNA fragments produced
from a number of different
sites in the genome that vary
in length.
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The DNA Fragments Are
Separated on the Basis of Size
The technique is gel electrophoresis.
The pattern of DNA bands is compared between
each sample loaded on the gel.
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Gel Electophoresis
A. Technique used to separate
nucleic acids or proteins by size
and charge.
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California Biology Content Standards:
California Content Standards:
5 b. Students know how to apply base-pairing
rules to explain precise copying of DNA.
5 c. Students know how genetic engineering
(biotechnology) is used to produce novel
biomedical and agricultural products.
5 e. Students know how exogenous DNA can
be inserted into bacterial cells to alter their
genetic makeup and support expression of
new protein products.
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DNA Review:
A. Structure: Double Helix
B. Location: Nucleus of Cell
C. Function: “Blue print of Life” – Creation
of Proteins/Amino Acids –
Transcription.
D. Nitrogen Base: ATCG
E. Nucleotide: Phosphate, Sugar
(Deoxyribose), Nitrogen Base (ATCG).
F. Base Pairing Rules:
A-T
C-G
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Genetically Modified (GM) Food
Genetically Modified Cotton
(contains a bacterial gene for
pest resistance)
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Standard Cotton
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Genetically Modified (GM) Food
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What is Genetic Engineering?
“Genetic engineering is the technology
for modifying the genetic
information in a plant, animal or
human in order to produce some
desired trait or characteristic”
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Genetic Engineering Vocabulary
A. Restriction Enzymes
“molecular scissors” are
enzymes that cut DNA only at
particular sequences.
B. Plasmids are small circles of
DNA found in bacteria.
C. Plasmids are used to replicate
a recombinant DNA.
D. Vector - A vector is a small
piece of DNA used to carry a
gene of interest.
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Genetic Engineering:
Recombinant DNA Technology
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Restriction Enzymes are
Enzymes that Cut DNA Only at
Particular Sequences
The enzyme EcoRI cutting DNA at its recognition sequence
Different restriction enzymes have different
recognition sequences.
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DNA Cut by a Restriction Enzymes
Can be Joined Together in New Ways
These are recombinant DNAs and they often
are made of DNAs from different organisms.
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Plasmids are Used to Replicate a
Recombinant DNA
A. Plasmids are small circles of DNA found in bacteria.
B. Plasmids replicate independently of the bacterial
chromosome.
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Human Insulin Production by Bacteria
1.
2.
3.
4.
5.
6.
Isolate human cells and grow them in tissue culture.
Isolate DNA from the human cells.
Isolate plasmid DNA from a bacterium.
Use the same restriction enzyme to cut the plasmid DNA.
Mix the recombinant plasmid with bacteria.
Allow the new bacteria to incorporate the recombinant
plasmid into the bacterial cell.
7. Grow trillions of new insulin producing bacteria (this is
when cloning takes place).
8. A fermentor is used to grow recombinant bacteria.
9. Collect the bacteria, break open the cells and purify the
insulin protein.
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Harnessing the Power of
Recombinant DNA Technology –
Human Insulin Production by
Bacteria
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Human Insulin Production by Bacteria
and cut with a restriction enzyme
6) join the plasmid and human fragment
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Human Insulin Production by Bacteria
Mix the recombinant
plasmid with bacteria.
Screening bacterial cells to learn which contain
the human insulin gene is the hard part.
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Route to the Production by
Bacteria of Human Insulin
One cell with the
recombinant plasmid
A fermentor used to grow
recombinant bacteria.
This is the step when gene cloning takes place.
The single recombinant plasmid replicates
within a cell.
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Route to the Production by
Bacteria of Human Insulin
The final steps are to collect the bacteria, break
open the cells, and purify the insulin protein
expressed from the recombinant human insulin gene.
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Overview of
gene cloning.
Route to the
Production by
Bacteria of
Human Insulin.
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Genetic Engineering:
Insulin Production Overview
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Monday (March 12, 2012)
Genetic Engineering

Journal Question: What is a plasmid?
*1. Lecture II: Genetic Engineering
2. Comprehensive Exam next Monday.
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Reviewing Genetic Engineering
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Banking Genes
A. The massive Svalbard Global
Seed Vault is built into the
permafrost deep in a mountain on
a remote arctic island in Norway
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Banking on Genes
B. Built in 2008
After receiving its first deposits, a
“doomsday” seed vault on an
Arctic island has amassed half a
million seed samples, making it the
world’s most diverse repository of
crop seeds.
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Most Widely Used Genetically
Modified Crops are…
1. Cotton plants with a built-in
resistance to insects.
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Most Widely Used Genetically
Modified Crops are…
2. Corn and Soybeans resistant to
the herbicide Roundup.
a. Allowing Farmers to employ no-till
techniques to farming.
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Which country is the leader in
plant biotechnology?
Answer: China
A. They have recently sequenced
the rice genome.
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Problems with Genetic
Engineering Technology
1. Environmental Problems
2. Food Safety
3. Access to the New Techniques
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Environmental Problems
A. Pest –resistant properties of transgenic crops.
B. If pests have a broad exposure to the toxin or
some other resistance incorporated into the plant, it
is possible that they will develop resistance to the
toxin and thus render it ineffective as an
independent pesticide.
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Food Safety
A. Food safety issues arise because
transgenic crops contain proteins
from different organisms and could
trigger an unexpected allergic
response to people who consume the
food.
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Access to the New Techniques
A. Relates to the developing world.
B. Farmers in the developing countries
are unable to afford the higher
cost of the new genetically altered
seeds.
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Other Types of Genetic Engineering:
1. Transgenic Engineering
a. Putting genetic information from one
type of plant or animal into another.
2. Cloning
a. Making exact genetic copies of an
existing plant or animal.
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Transgenic Organisms
A. An organism is called “transgenic”
if it has genetic information
added to it from a different type
of organism.
B. Viruses do something of this sort
when they infect plants, animals
or humans.
C. Humans have begun to do this
with plants and animals.
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Transgenic Organisms
D. This is the work that is furthest
along:
(1) Corn with its own insecticide.
(2) Soybeans & cotton resistant to
herbicides.
(3) Papayas resistant to viruses
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Transgenic Organisms
F. Human genes have been
inserted into:
(1) Bacteria (Prokaryotes)
(2) Mice
G. To produce various
human proteins for treating
diseases.
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Making Transgenic Mice
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Advantages of Transgenic Organisms
A. Plants:
(1) More disease-resistant.
(2) Larger yields.
(3) More transportable.
B. Animals:
(1) Make proteins for medicinal
purposes.
(2) Make organs for transplant
to humans.
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Cloning: “Exact Copies”
A. A “clone” is an exact copy.
B. In genetics, a clone is a genetic copy of another organism.
C. Clones occur naturally:
 Asexual breeding in plants & lower animals
 Identical twins (triplets) in higher animals
D. For centuries it has been known that simple animals –
worms & starfish – can be cloned by cutting them in half.
E. This doesn’t work for higher animals!
F. Part of the problem is cell specialization:
 Nerve, Bone, Muscle, etc.
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Cloning in the
th
20
Century
A. We now realize that each specialized
cell has all the genetic information,
but much of it is turned off.
B. Problem – how to reset the “program”
so this information is usable?
C. Cloning of frogs successful in 1950s
D. Cloning of livestock from fetal cells
in 1970s.
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Cloning in the 20th Century
E. The human genome (an
organism’s genetic material)
consists of 3 billion base pairs of
DNA and about 30,000 genes.
(1) 97% of our DNA does not
code for protein product.
-mostly consisting of repetitive
sequences that never get
transcribed.
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Cloning in the 20th Century: Hello Dolly
F. Clone from an adult sheep cell by
Scots researchers under Ian Wilmut.
G. Had only one success in 300
attempts.
H. Dolly grew to maturity, and
successfully
had a lamb by natural means in 1998.
I. But Dolly seems to be prematurely old.
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Cloning
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Cloning
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Genetic Engineering
Genetic engineering (also known
as genetic manipulation or GM)
is not the same as cloning.
-Though cloning techniques are
used in genetic engineering, the
two processes should not be
confused.
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Genetic Engineering
versus Cloning
A. Cloning:
1. Produces exact copies
2. Genes replicated within the
same species.
B. Genetic Engineering:
1. Produces a totally unique
set of genes.
2. Genes can be swapped
across species.
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Selective Breeding versus Genetic Engineering
A. In the past, humans have brought
about change in the genetic make-up
of organisms by means of selective
breeding (artificial selection) i.e.
Purebreds
B. Genetic engineering brings about
such change by scientifically altering
an organism's genetic code.
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Genetic Engineering Overview
1. In genetic engineering enzymes are used to
cut up and join together parts of the DNA of
one organism, and insert them into the DNA
of another organism.
2. In the resulting new organism the inserted
genes will code for one or more new
characteristics - for example producing a new
substance, or performing a new function. The
organism has been genetically reengineered
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Other names for Genetic Engineering:
A. This technique is also known as
gene splicing or recombinant
DNA technology (because the
DNA is recombined in the vector
molecule.
B. Vector - A vector is a small
piece of DNA used to carry a
gene of interest. Besides the gene
being studied, a vector may contain
elements which are used to help
the gene integrate into a genome.
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Why does genetic
engineering work?
A. Genetic engineering works
because there is only one code
for life. The set of instructions for
which a gene is responsible work
whichever organism the gene is
in, and whatever instructions that
gene gives are carried out within
the cells of the recipient.
B. Theoretically the possibilities are
limitless, although this sort of
manipulation gives rise to strong
feelings for and against.
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Applications of Genetic Engineering
A. One field in which genetic engineering
has had a huge impact is the mass
production of insulin to help
diabetics. Scientists have isolated the
gene responsible for making human
proteins, including the insulin hormone.
This gene is inserted into the bacterial
DNA, and the microbes then clone
themselves rapidly, making identical
copies of themselves, all with the new
gene and all capable of making human
insulin.
B. This is a cheap way of producing
sufficient quantities of exactly the right
hormone, for everyone who needs it.
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Other Applications of Genetic Engineering
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C. Producing interferon, a human
protein which stops viruses
multiplying inside the body.
D. Producing human growth hormone
to treat growth abnormalities
E. Blood clotting factor to treat
hemophiliacs.
F. Used in industry to produce
enzymes for use in biological
washing powder.
G. Producing pest resistant crop
varieties.
H. Producing tomatoes and other
produce that stay fresh much
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longer.
Introduction to Genetic Engineering
1. With genetic engineering
scientists directly manipulate
genes.
a. It frequently involves the use
of recombinant DNA, which is
composed of DNA segments
from at least two different
organisms.
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Commercial Applications
1. An example is the use of
recombinant DNA technology
to make interferon, a virusdestroying protein naturally
produced by the human body.
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Production of Synthetic Interferon Involves:
1. Isolating the human gene that codes
for the interferon production.
2. Splicing this gene into a strand of
bacterial DNA.
3. Inserting recombinant DNA into a
bacterium.
4. Cloning the bacterium and collecting
the product: Interferon.
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Isolation of a Gene
A. The first step in the process is
isolating the human interferon
gene.
B. Genetic engineers use
restriction enzymes, proteins
that cut a DNA molecule into
pieces.
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Isolation of a Gene
C. The restriction enzyme EcoRI
cuts DNA wherever the sequence
C-T-T-A-A-G occurs.
D. Other restriction enzymes cut
DNA at different nucleotide
sequences.
E. By using the proper restriction
enzymes scientists can cut the
human interferon gene out of its
chromosome.
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Gene Splicing
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Isolation of a Gene
F. Once the gene for
interferon is removed,
it is separated from
the rest of the DNA
and then inserted
into a strand of
bacterial DNA.
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Gene Splicing
A. Gene splicing is the process by
which a gene from one organism
is placed into the DNA of
another organism.
B. The human interferon gene is
placed into the DNA of E. coli,
the common bacterium of the
human intestine.
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Gene Splicing
C. In addition to a single, circular
chromosome, E. coli contains a
single, small ring of DNA called a
plasmid.
(Plasmid = a single ring of DNA in
bacteria)
D. Human DNA is inserted into this
plasmid.
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Gene Splicing
E. The plasmid ring is removed
from the bacterium and the
opened with a restriction
enzyme.
F. The human interferon gene and
the bacterial plasmid have
“sticky ends” –unpaired bases
at each end of the DNA
segment, where they were
cleaved by restriction
enzymes.
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Gene Splicing
G. As the human DNA is spliced
into the plasmid DNA, the
unpaired bases of each bond
readily.
H. Consequently, a newly formed
plasmid contains both human
and bacterial DNA.
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Insertion, Cloning, and Collecting
A. Once a DNA fragment is
incorporated into a plasmid, the
plasmid is inserted into another
bacterium, which is then placed in a
culture medium, where it divides and
replicates.
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Insertion, Cloning, and Collecting
B. Each time a bacterium divides a
new copy of the plasmid DNA,
which includes the human DNA
gene, is created.
C. This process by which the human
gene is replicated is called gene
cloning
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Insertion, Cloning, and Collecting
D. Because E. coli can divide every
20 minutes, gene cloning is an
efficient way to produce many
copies of a specific genetic
sequence.
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Insertion, Cloning, and Collecting
E. The gene for human interferon is
thus expressed in bacterial cultures
and the resulting interferon protein
is collected and eventually used by
physicians.
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Genetically Modified (GM) Crops

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The ear of genetically engineered
corn at top contains a toxin that
kills worms.
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