Recombinant DNA and
Genetic Engineering
Chapter 12
Goals for this chapter
Have a general understanding of
Genetic Engineering and Biotechnology
Be able to form an opinion that is based
on fact or emotion
And recognize the difference
Focus our attention on
Genetic Improvement of Crop Plants
Other possible topics
Genetic improvement of animals
Genetic improvement of Humans
Stem cell therapy
Forensics
Historical research
And on and on
What is Biotechnology
Definitions
Biotechnology
Genetic Engineering
Recombinant DNA
Transgenic or GMO
Biotechnology
Genetic Improvement of plants and
animals
This would include the activities of Plant
Breeders
And plant breeders are really nice people
Genetic Changes
Humans have been changing the genetics
of other species for thousands of years
Artificial selection of plants and animals
Natural processes also at work
Mutation, crossing over
Traditional plant breeding
Select parents
Cross and generate variable offspring
Select the desired types
Test
-
Test
-
Test
Multiply
Release
7 to 15 years
Norman Borlaug
Nobel Peace Prize
1970
The Green Revolution
http://nobelprize.org/peace/laureates/
1970/borlaug
-
lecture.html
Barbara Mclintock
Transposons
1983 Nobel Prize
in Medicine
Genetic Engineering
Modern Biotechnology
-
which uses the
knowledge of DNA to manipulate the genetic
makeup of an organism
Recombinant DNA
-
take a gene from one
organism and place it into another organism
Transgenic or GMO
-
an organism that
contains DNA from another organism
Would You Eat a
Genetically Engineered
Food?
Most GMO
’
s are Plants
34% of Corn
71% of Cotton
75% of soybeans
Silk is Soy
Why no GMO
Until recently the terms Genetically Modified
Organism (GMO), GMO
-
Free and Non
-
GMO
were used to help identify foods that
contained genetically altered ingredients.
These terms are no longer recognized by the
Food and Drug Administration (FDA) and
therefore cannot be used on food packaging.
What about Tostito
’
s
Or Pepsi
Or Coke
Or CapN Crunch???
How to Manipulate DNA
in the Lab
Examples of Transformation
Natural Systems
Bacteria
Viruses
Bacterium
bacterial
chromosome
plasmid
Transformation with DNA fragment
bacterial
chromosome
DNA
fragments
Virus enters host cell.
2
virus
viral DNA
host cell
host cell DNA
“hybrid virus”
viral proteins
viral DNA
Virus attaches to
susceptible host cell.
1
Virus releases its DNA into
host cell; some viral DNA (red)
may be incorporated into the
host cell’s DNA (blue).
3
Viral genes encode synthesis
Of viral proteins and viral gene
Replication. Some host cell DNA
May attach to replicated viral
DNA (red/blue).
4
New viruses assemble; host
cell DNA is carried by “hybrid
viruses.”
5
Host cell bursts, releasing
newly assembled viruses.
when “hybrid viruses” infect a
second cell, they may transfer
genes from the first cell to the
second cell.
6
GE Tool Box
Restiction Enzymes
Cloning Vectors
cDNA Cloning
Reverse
Transcriptase
PCR
Gene Library
(Isolation)
Transformation of
Plants
Based on the Central Dogma and the fact that in
virtually organisms the CODE is perfectly conserved
almost
Amplifying DNA
Fragments can be inserted into
fast
-
growing microorganisms
Polymerase chain reaction (PCR)
Polymerase Chain Reaction
Sequence to be copied is heated
Primers are added and bind to ends of
single strands
DNA polymerase uses free nucleotides
to create complementary strands
Doubles number of copies of DNA
Polymerase
Chain
Reaction
Double
-
stranded
DNA to copy
DNA heated to
90
°
–
94
°
C
Primers added to
base
-
pair with
ends
Mixture cooled;
base
-
pairing of
primers and ends
of DNA strands
DNA polymerases
assemble new
DNA strands
Fig. 16
-
6, p. 256
Stepped Art
Polymerase
Chain
Reaction
Stepped Art
Mixture heated again;
makes all DNA
fragments unwind
Mixture cooled; base
-
pairing between
primers and ends of
single DNA strands
DNA polymerase
action again
doubles number of
identical DNA
fragments
Fig. 16
-
6, p. 256
Fig. 16
-
7, p.247
DNA Fingerprinting
Guilty or Innocent
8 side
-
by
-
side (tandem) repeats
of the same 4
-
nucleotide sequence,
Nylon paper with DNA is bathed in a solution of labeled DNA probes (red) that
are complementary to specific DNA segments in the original DNA sample.
Complementary DNA segments are labeled by probes
(red bands).
nylon paper
solution of DNA probes (red)
gel
gel
power supply
DNA bands
(not yet visible)
�
�
wells
pipetter
nylon
paper
DNA samples are pipetted into wells
(shallow slots) in the gel. Electrical current
is sent through the gel (negative at end
with wells, positive at opposite end).
Electrical current moves DNA
segments through the gel. Smaller
pieces of DNA move farther toward the
positive electrode.
Gel is placed on special nylon
paper. Electrical current drives
DNA out of gel onto nylon.
�
�
gel
power supply
�
�
wells
pipetter
DNA samples are pipetted into wells
(shallow slots) in the gel. Electrical current
is sent through the gel (negative at end
with wells, positive at opposite end).
�
�
DNA bands
(not yet visible)
�
�
Electrical current moves DNA
segments through the gel. Smaller
pieces of DNA move farther toward the
positive electrode.
�
�
gel
�
�
nylon
paper
Gel is placed on special nylon
paper. Electrical current drives
DNA out of gel onto nylon.
�
�
Nylon paper with DNA is bathed in a solution of labeled DNA probes (red) that
are complementary to specific DNA segments in the original DNA sample.
nylon paper
solution of DNA probes (red)
�
�
�
�
Complementary DNA segments are labeled by probes
(red bands).
�
�
�
�
STR name
Penta D
CSF
D16
D7
D13
D5
D16: an STR on chromosome 16
DNA samples from
13 different people
Number of repeats
STR name
Penta D
CSF
D16
D7
D13
D5
Number of repeats
D16: an STR on chromosome 16
DNA samples from
13 different people
Number of repeats
Genetic Engineering
Transformation of Plants
Genes are isolated, modified, and
inserted into an organism
Made possible by recombinant
technology
Cut DNA up and recombine pieces
Amplify modified pieces
Process
Board Diagram
Corn Transformation with RR gene
From a bacteria or petunia
Hypothetical Situation
Corn Cotton and Alfalfa
Roughly 400 million people in the world today are at risk of Vitamin A
deficiency, which already affects 100
-
200 million children. Vitamin A
deficiency causes various health problems, including blindness. Because
rice is an important crop, eaten by almost half of the people in the world,
the Rockefeller Foundation and the European Union funded research
into varieties that might offer global health benefits.
It may now be possible, thanks to agricultural biotechnology, to make rice
and other crops into additional sources of Pro
-
Vitamin A. With
Monsanto's help, the developers of "Golden Rice" and mustard with more
Pro
-
Vitamin A should one day be able to deliver their gift of better
nutrition to the developing nations of the world through staple crops
readily available to poor and vulnerable populations
Imagine sharing science to help others develop crops that could help
reduce Vitamin A deficiency, a leading cause of blindness and infection
among the young.
Imagine innovative agriculture that creates incredible things.
Discussion
Debate the Merits or Dangers of Golden
Rice.
Group One
-
Make your case in front of
Congress to obtain money to distribute
this rice (as rice seed) to the farmers of
Southeast Asia and Africa
Group Two
-
Argue against this.
You be the judge
With your pocket book
Or your advocacy
Ethical Issues
Who decides what should be “corrected”
through genetic engineering?
Should animals be modified to provide
organs for human transplants?
Should humans be cloned?
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