Download Chapter 17 Recombinant DNA and Biotechnology

Chapter 17: Recombinant DNA and Biotechnology
CHAPTER 17
Recombinant DNA and
Biotechnology
Chapter 17: Recombinant DNA and Biotechnology
Chapter 17: Recombinant
DNA and Biotechnology
Cleaving and Rejoining DNA
Cloning Genes
Sources of Genes for Cloning
Some Additional Tools for DNA Manipulation
Biotechnology: Applications of DNA
Manipulation
Chapter 17: Recombinant DNA and Biotechnology
Cleaving and Rejoining DNA
• Knowledge of DNA transcription, translation,
and replication has been used to create
recombinant DNA molecules, made up of
sequences from different organisms.
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Chapter 17: Recombinant DNA and Biotechnology
Cleaving and Rejoining DNA
• Restriction enzymes, which are made by
microbes as a defense mechanism against
viruses, bind to DNA at specific sequences
and cut it.
Review Figure 17.1
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Chapter 17: Recombinant DNA and Biotechnology
17.1
Figure 17.1
figure 17-01.jpg
Chapter 17: Recombinant DNA and Biotechnology
Cleaving and Rejoining DNA
• DNA fragments generated from cleavage by
restriction enzymes can be separated by
size using gel electrophoresis.
• The fragments' sequences can be further
identified by hybridization with a probe.
Review Figures 17.2, 17.3
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Chapter 17: Recombinant DNA and Biotechnology
17.2
Figure 17.2
figure 17-02.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.3
Figure 17.3
figure 17-03.jpg
Chapter 17: Recombinant DNA and Biotechnology
Cleaving and Rejoining DNA
• Many restriction enzymes make staggered
cuts in the two strands of DNA, creating
“sticky ends” with unpaired bases.
• The sticky ends can be used to create
recombinant DNA if DNA molecules from
different species are cut with the same
restriction enzyme.
Review Figure 17.4
Chapter 17: Recombinant DNA and Biotechnology
17.4
Figure 17.4
figure 17-04.jpg
Chapter 17: Recombinant DNA and Biotechnology
Cloning Genes
• Bacteria, yeasts, and cultured plant cells are
commonly used as hosts for recombinant
DNA experiments.
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Chapter 17: Recombinant DNA and Biotechnology
Cloning Genes
• Newly introduced DNA must be part of a
replicon if it is to be propagated in host
cells.
• One way to assure this is to introduce it as
part of a carrier DNA, or vector, that has a
replicon.
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Chapter 17: Recombinant DNA and Biotechnology
Cloning Genes
• Specialized vectors transfect bacteria,
yeasts, and plant cells.
• These must contain a replicon, recognition
sequences for restriction enzymes, and
genetic markers to identify their presence in
host cells.
Review Figure 17.5
Chapter 17: Recombinant DNA and Biotechnology
17.5
Figure 17.5
figure 17-05.jpg
Chapter 17: Recombinant DNA and Biotechnology
Cloning Genes
• Naked DNA may be introduced into a host
cell by chemical or mechanical means.
• In this case, the DNA must integrate into
the host DNA by itself.
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Chapter 17: Recombinant DNA and Biotechnology
Cloning Genes
• When vectors carrying recombinant DNA are
incubated with host cells, nutritional,
antibiotic resistance, or fluorescent markers
can identify which cells contain the vector.
Review Figure 17.6
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Chapter 17: Recombinant DNA and Biotechnology
17.6
Figure 17.6 – Part 1
figure 17-06a.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.6
Figure 17.6 – Part 2
figure 17-06b.jpg
Chapter 17: Recombinant DNA and Biotechnology
Sources of Genes for Cloning
• The cutting of DNA by a restriction enzyme
produces many fragments that can be
individually and randomly combined with a
vector and inserted into a host to create a
gene library.
Review Figure 17.8
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Chapter 17: Recombinant DNA and Biotechnology
17.8
Figure 17.8
figure 17-08.jpg
Chapter 17: Recombinant DNA and Biotechnology
Sources of Genes for Cloning
• The mRNA’s produced in a certain tissue at
a certain time can be extracted and used to
create complementary DNA (cDNA) by
reverse transcription.
• This cDNA is then used to make a library.
Review Figure 17.9
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Chapter 17: Recombinant DNA and Biotechnology
17.9
Figure 17.9
figure 17-09.jpg
Chapter 17: Recombinant DNA and Biotechnology
Sources of Genes for Cloning
• A third source of DNA is synthetic DNA
made in the laboratory.
• The methods of organic chemistry can be
used to create specific, mutated DNA
sequences.
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Chapter 17: Recombinant DNA and Biotechnology
Some Additional Tools for
DNA Manipulation
• Homologous recombination can be used to
“knock out” a gene in an organism.
Review Figure 17.10
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Chapter 17: Recombinant DNA and Biotechnology
17.10
Figure 17.10 – Part 1
figure 17-10a.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.10
Figure 17.10 – Part 2
figure 17-10b.jpg
Chapter 17: Recombinant DNA and Biotechnology
Some Additional Tools for
DNA Manipulation
• DNA chip technology permits the screening
of thousands of sequences at the same
time.
Review Figure 17.11
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Chapter 17: Recombinant DNA and Biotechnology
figure 17-11.jpg
17.11
Figure 17.11
Chapter 17: Recombinant DNA and Biotechnology
Some Additional Tools for
DNA Manipulation
• An antisense RNA complementary to a
specific mRNA can prevent its translation by
hybridizing to the mRNA.
Review Figure 17.12
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Chapter 17: Recombinant DNA and Biotechnology
17.12
Figure 17.12
figure 17-12.jpg
Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• The ability to clone genes has made
possible many new applications of
biotechnology, such as the large-scale
production of eukaryotic gene products.
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Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• For a vector carrying a gene of interest to
be expressed in a host cell, the gene must
be adjacent to appropriate sequences for its
transcription and translation in the host cell.
Review Figure 17.13
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Chapter 17: Recombinant DNA and Biotechnology
17.13
Figure 17.13
figure 17-13.jpg
Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• Recombinant DNA and expression vectors
have been used to make medically useful
proteins that would otherwise have been
difficult to obtain in necessary quantities.
Review Figure 17.14, Table 17.1
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Chapter 17: Recombinant DNA and Biotechnology
17.14
Figure 17.14 – Part 1
figure 17-14a.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.14
Figure 17.14 – Part 2
figure 17-14b.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.1
Table 17.1
table 17-1.jpg
Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• Because plant cells can be cloned to
produce adult plants, introduction of new
genes into plants via vectors has been
advancing rapidly.
• The result is crop plants carrying new,
useful genes.
Review Table 17.2
Chapter 17: Recombinant DNA and Biotechnology
17.2
Table 17.2
table 17-2.jpg
Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• “Pharming” uses transgenic dairy animals
that produce useful products in their milk.
Review Figure 17.15
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Chapter 17: Recombinant DNA and Biotechnology
17.15
Figure 17.15
figure 17-15.jpg
Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• There is public concern about the
applications of biotechnology to food
production.
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Chapter 17: Recombinant DNA and Biotechnology
Biotechnology: Applications
of DNA Manipulation
• Because the DNA of an individual is unique,
the polymerase chain reaction can be used
to identify an organism from a small sample
of its cells, and to create a DNA fingerprint.
Review Figures 17.17, 17.18
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Chapter 17: Recombinant DNA and Biotechnology
17.17
Figure 17.17
figure 17-17.jpg
Chapter 17: Recombinant DNA and Biotechnology
17.18
Figure 17.18
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