Download DNA Sequencing

13
The Molecular
Basis of Inheritance
PowerPoint Lectures for
Campbell Biology: Concepts & Connections, Seventh Edition
Reece, Taylor, Simon, and Dickey
© 2012 Pearson Education, Inc.
Lecture by Edward J. Zalisko
What is DNA Technology/genetic engineering?
Process of
– Manipulating genes either across species or within
individuals of the same species
– Produce new traits not already found on the organism
– Change the traits already found to a new variant
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Why DNA Technology/genetic engineering?
– permits the use of gene cloning to produce medical
and industrial products,
– allows for the development of genetically modified
organisms for agriculture,
– has rapidly revolutionized the field of forensics,
– permits the investigation of historical questions about
human family and evolutionary relationships, and
– is invaluable in many areas of biological research.
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Prerequisites for DNA technology/ Genetic
Engineering
Some discoveries that made it possible:
1. Restriction enzymes (1960s) from E. coli by Linn and
Arber (Nobel in 1978)
2. DNA Cloning –Cohen and Boyer created the first
genetically modified organism (1996 Lemelson-MIT Prize for
Invention and Innovation.)
3. Polymerase Chain Reaction (PCR) 1983 by Kary Mullis –
(Nobel in 1993) process by which amount of DNA can be
increased (amplified) by many rounds DNA replication in a
test tube
4. Gel Electrophoresis
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Some terms of Genetic Engineering
 Genetic engineering involves manipulating
genes for practical purposes.
– Gene cloning leads to the production of multiple,
identical copies of a gene-carrying piece of DNA.
– Recombinant DNA is formed by joining nucleotide
sequences from two different sources.
– One source contains the gene that will be cloned.
– Another source is a gene carrier, called a vector.
– Plasmids (small, circular DNA molecules independent of the
bacterial chromosome) are often used as vectors.
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Some terms of Genetic Engineering
 Biotechnology is the manipulation of organisms or
their components to make useful products.
 For thousands of years, humans have
– Selected and used microbes to make wine and cheese
– selectively bred stock, dogs, and other animals.
 DNA technology is the set of modern techniques
used to study and manipulate genetic material.
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Enzymes are used to “cut and paste” DNA
 Restriction enzymes cut DNA at specific
sequences.
– Each enzyme binds to DNA at a different restriction
site.
– Many restriction enzymes make staggered cuts that
produce restriction fragments with single-stranded
ends called “sticky ends.”
– Fragments with complementary sticky ends can
associate with each other, forming recombinant DNA.
 DNA ligase joins DNA fragments together.
Animation: Restriction Enzymes
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Figure 12.2_s1
1
DNA
Restriction enzyme
recognition sequence
A restriction
enzyme cuts
the DNA into
fragments.
2
Sticky
end
Restriction
enzyme
Sticky
end
Figure 12.2_s2
1
DNA
Restriction enzyme
recognition sequence
A restriction
enzyme cuts
the DNA into
fragments.
2
Sticky
end
A DNA fragment
from another
source is added.
Restriction
enzyme
Sticky
end
3
Gene of
interest
Figure 12.2_s3
1
DNA
Restriction enzyme
recognition sequence
A restriction
enzyme cuts
the DNA into
fragments.
2
Sticky
end
A DNA fragment
from another
source is added.
Two (or more)
fragments stick
together by
base pairing.
4
Restriction
enzyme
Sticky
end
3
Gene of
interest
Figure 12.2_s4
1
DNA
Restriction enzyme
recognition sequence
A restriction
enzyme cuts
the DNA into
fragments.
2
Sticky
end
A DNA fragment
from another
source is added.
Restriction
enzyme
Sticky
end
Gene of
interest
3
Two (or more)
fragments stick
together by
base pairing.
4
DNA ligase
pastes the
strands together.
5
DNA ligase
Recombinant
DNA molecule
Figure 12.1B
E. coli bacterium
Plasmid
Bacterial
chromosome
1
A cell with DNA
containing the gene
of interest
2
A plasmid
is isolated.
The cell’s DNA
is isolated.
Gene of
interest
DNA
Cloning
3
DNA
The plasmid is cut
with an enzyme.
Examples of gene use
4
The cell’s DNA is cut
with the same enzyme.
Gene
of interest
5
6
The targeted fragment
and plasmid DNA
are combined.
DNA ligase is added,
which joins the two
DNA molecules.
Examples of protein use
Recombinant
DNA
plasmid
Gene
of interest
7
The recombinant plasmid
is taken up by a bacterium
through transformation.
Recombinant
bacterium
8
Clone
of cells
Genes may be inserted
into other organisms.
The bacterium
reproduces.
9
Harvested
proteins
may be
used
directly.
Figure 12.1B_s1
E. coli
bacterium
Bacterial
chromosome
A cell with DNA
containing the gene
of interest
Plasmid
1
2
A plasmid
is isolated.
Gene of
interest
The cell’s DNA
is isolated.
DNA
Figure 12.1B_s2
E. coli
bacterium
Bacterial
chromosome
A cell with DNA
containing the gene
of interest
Plasmid
1
2
A plasmid
is isolated.
The cell’s DNA
is isolated.
Gene of
interest
3
DNA
The plasmid is cut
with an enzyme.
4
The cell’s DNA is cut
with the same enzyme.
Gene
of interest
Figure 12.1B_s3
E. coli
bacterium
Bacterial
chromosome
A cell with DNA
containing the gene
of interest
Plasmid
1
2
A plasmid
is isolated.
The cell’s DNA
is isolated.
Gene of
interest
3
DNA
The plasmid is cut
with an enzyme.
4
The cell’s DNA is cut
with the same enzyme.
Gene
of interest
5
The targeted fragment
and plasmid DNA
are combined.
Figure 12.1B_s4
E. coli
bacterium
Bacterial
chromosome
A cell with DNA
containing the gene
of interest
Plasmid
1
2
A plasmid
is isolated.
The cell’s DNA
is isolated.
Gene of
interest
3
DNA
The plasmid is cut
with an enzyme.
4
The cell’s DNA is cut
with the same enzyme.
Gene
of interest
5
6
Recombinant
DNA
plasmid
The targeted fragment
and plasmid DNA
are combined.
DNA ligase is added,
which joins the two
DNA molecules.
Gene
of interest
Figure 12.1B_s5
Recombinant
DNA
plasmid
Gene
of interest
7
Recombinant
bacterium
The recombinant plasmid
is taken up by a bacterium
through transformation.
Figure 12.1B_s6
Recombinant
DNA
plasmid
Gene
of interest
7
The recombinant plasmid
is taken up by a bacterium
through transformation.
8
The bacterium
reproduces.
Recombinant
bacterium
Clone
of cells
Figure 12.1B_s7
Genes may be inserted
into other organisms.
Recombinant
DNA
plasmid
Gene
of interest
7
The recombinant plasmid
is taken up by a bacterium
through transformation.
Recombinant
bacterium
8
Clone
of cells
The bacterium
reproduces.
9
Harvested
proteins
may be
used
directly.
Figure 13.22b
Gene of
interest
Protein expressed
from gene of interest
Copies of gene
Protein harvested
4 Basic
research
and various
applications
Gene for pest resistance
inserted into plants
Human growth hormone
treats stunted growth
Gene used to alter bacteria
for cleaning up toxic waste
Protein dissolves blood clots
in heart attack therapy
DNA Cloning: Making Multiple Copies of a Gene or
Other DNA Segment
Steps in cloning a gene
1. Plasmid DNA is isolated.
2. DNA containing the gene of interest is isolated.
3. Plasmid DNA is treated with a restriction enzyme that
cuts in one place, opening the circle.
4. DNA with the target gene is treated with the same
enzyme and many fragments are produced.
5. Plasmid and target DNA are mixed and associate with
each other.
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12.1 Genes can be cloned in recombinant plasmids
6. Recombinant DNA molecules are produced when
DNA ligase joins plasmid and target segments
together.
7. The recombinant plasmid containing the target gene
is taken up by a bacterial cell.
8. The bacterial cell reproduces to form a clone, a group
of genetically identical cells descended from a single
ancestral cell.
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Concept Check
Restriction enzymes are useful tools for cutting DNA
fragments. What is the function of restriction enzymes in
their normal bacterial environment?
a)
Restriction enzymes remove and recycle old mRNAs.
b)
Restriction enzymes cut up DNA taken from the
environment and used as a nutrient source.
c)
Restriction enzymes remove the excess DNA that
results from DNA replication.
d)
Restriction enzymes cut DNA from viruses or other
species at specific sequences disrupting these genes.
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Answer

Restriction enzymes are useful tools for cutting DNA
fragments. What is the function of restriction
enzymes in their normal bacterial environment?
d)
Restriction enzymes cut DNA from viruses or other
species at specific sequences disrupting these genes.
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Cloned genes can be stored in libraries
 A genomic library is a collection of all of the
cloned DNA fragments from a target genome.
 Genomic libraries can be constructed with
different types of vectors:
– plasmid library: genomic DNA is carried by plasmids,
– bacteriophage (phage) library: genomic DNA is
incorporated into bacteriophage DNA,
– bacterial artificial chromosome (BAC) library:
specialized plasmids that can carry large DNA
sequences.
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Figure 12.3
A genome is cut up with
a restriction enzyme
or
Recombinant
plasmid
Recombinant
phage DNA
Bacterial
clone
Phage
clone
Plasmid library
Phage library
Reverse transcriptase can help make genes for
cDNA library
 Complementary DNA (cDNA) can be used to
clone eukaryotic genes.
– In this process, mRNA from a specific cell type is the
template.
– Reverse transcriptase produces a DNA strand from
mRNA.
– DNA polymerase produces the second DNA strand.
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Figure 12.4_1
How Reverse Transcriptase works
CELL NUCLEUS
Exon Intron
DNA of a
eukaryotic
gene
Exon
Intron Exon
1 Transcription
RNA
transcript
2 RNA splicing (removes
introns and joins exons)
mRNA
Figure 12.4_2
How Reverse Transcriptase works
3 Isolation of mRNA from
TEST TUBE
Reverse transcriptase
cDNA strand
being synthesized
the cell and the addition
of reverse transcriptase;
synthesis of a DNA strand
4 Breakdown of RNA
Direction
of synthesis
5 Synthesis of second
DNA strand
cDNA of gene
(no introns)
Reverse transcriptase can help make genes for
cloning
 Advantages of cloning with cDNA include the
ability to
– study genes responsible for specialized characteristics
of a particular cell type and
– obtain gene sequences
– that are smaller in size,
– easier to handle, and
– do not have introns.
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The PCR method is used to amplify DNA
sequences
 Polymerase chain reaction (PCR) is a method of
amplifying a specific segment of a DNA molecule.
 PCR relies upon a pair of primers that are
– short,
– chemically synthesized, single-stranded DNA
molecules, and
– complementary to sequences at each end of the target
sequence.
 PCR
– is a three-step cycle that
– doubles the amount of DNA in each turn of the cycle.
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Figure 12.12_1
Cycle 1
yields two molecules
Genomic
DNA
3
5
1 Heat
3
5
5
3
separates
DNA
strands.
3
5
5
2 Primers bond
with ends
of target
sequences.
Target
sequence
3
5
3
3 DNA
polymerase
adds
nucleotides.
3
5
5
3
5
3
Primer
5
5
5
New DNA
3
Figure 13.25a
5
3
Target sequence
Genomic DNA
3
5
Figure 13.25b-1
1 Denaturation
5
3
3
5
Use heat to break H bonds
Cycle 1
yields 2
molecules
Figure 13.25b-2
1 Denaturation
5
3
3
5
2 Annealing
Cycle 1
yields 2
molecules
Primers
Cool down to allow H bonds to form with Primers
Why do the two DNA molecules not re-anneal instead?
Figure 13.25b-3
1 Denaturation
5
3
3
5
2 Annealing
Cycle 1
yields 2
molecules
Primers
3 Extension
What is needed here?
New
nucleotides
Figure 13.25
Technique
5
3
Target sequence
Genomic DNA 3
1 Denaturation
5
5
3
3
5
2 Annealing
Cycle 1
yields 2 molecules
Primers
3 Extension
New
nucleotides
Cycle 2
yields 4 molecules
Cycle 3
yields 8 molecules;
2 molecules
(in white boxes)
match target sequence
The PCR method is used to amplify DNA
sequences
 The advantages of PCR include
– the ability to amplify DNA from a small sample,
– obtaining results rapidly, and
– a reaction that is highly sensitive, copying only the
target sequence.
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Figure 12.11
Application of PCR
to Forensics
Crime scene Suspect 1
1
DNA is
isolated.
2 The DNA of
selected
markers is
amplified.
3
The amplified
DNA is
compared.
Suspect 2
Concept Check
Polymerase chain reaction (PCR) amplifies target DNA fragments.
This technique takes place outside of a cell and uses heat to separate
the double-stranded DNA along with which of the following?
a)
Restriction enzymes from E. coli bacteria
b)
DNA polymerase isolated from bacteria from hot springs
c)
Radioactive probes
d)
Plasmids from E. coli or other bacteria
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Answer
Polymerase chain reaction (PCR) amplifies target DNA fragments.
This technique takes place outside of a cell and uses heat to separate
the double-stranded DNA along with which of the following?
b)
DNA polymerase isolated from bacteria from hot springs
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How to identify clones carrying specific sequences
Southern Blotting
 If the DNA sequence is known use Nucleic acid
probes.
 Noncoding regions – RFLP analysis
– Chromosomes are fragmented with specific restriction
enzymes
– Probes can be DNA or RNA sequences
complementary to a portion of the gene of interest.
– A probe binds to DNA by base pairing.
– Detected by Southern blotting
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How to identify clones carrying specific sequences
SOUTHERN BLOTTING
Screen a gene library for a particular gene 1. Cells are broken apart and the DNA is separated into
single strands/fragmented by specific restriction
enzymes
2. Gel electrophoresis separates all the fragments
(thousands generated from one genome)
3. The DNA is denatured and transferred on filter paper
(nitrocellulose)
4. Filter soaked with radioactive probe which anneals to
complementary parts of the DNA
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Figure 12.5
Radioactive
nucleic acid probe
(single-stranded DNA)
The probe is mixed with
single-stranded DNA
from a genomic library.
Single-stranded
DNA
Base pairing
highlights the
gene of interest.
Nucleic acid probes identify clones carrying
specific genes
 5. Bands show up
when photographic film
shows bands where
radioactivity probe
annealed to DNA
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Gel electrophoresis sorts DNA molecules by size
 Gel electrophoresis - separate DNA molecules
based on size as follows:
1. A DNA sample is placed at one end of a porous gel.
2. Current is applied and DNA molecules move from the
negative electrode toward the positive electrode.
3. Shorter DNA fragments move through the gel matrix
more quickly and travel farther through the gel.
4. DNA fragments appear as bands, visualized through
staining or detecting radioactivity or fluorescence.
5. Each band is a collection of DNA molecules of the
same length.
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STR analysis is commonly used for DNA
profiling
 Short tandem repeats (STRs) are short nucleotide
sequences (2-6 bases) repeated in tandem,
– composed of different numbers of repeating units in
individuals Ex. GATAGATAGATAGATA
– Once determined in an individual, it is put in the
database CODIS (Combined DNA Index System) like a
fingerprint
– 15 CODIS are used for DNA profiling
– Each person inherits these from each parent according
to Mendelian inheritance pattern and are co-dominant
– Ex, One STR locus contains 8 alleles numbered 13-20
but each person can have only two of the 8
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STR analysis is commonly used for DNA profiling
 Used in Paternity cases,
criminal investigations
 Ex: Alleged Dad has
[13,15] combination
 Mom has [14,14]
 Child has [14,15]
 Is he the Father?
CONNECTION: DNA profiling has provided
evidence in many forensic investigations
 DNA profiling is used to
– determine guilt or innocence in a crime,
– settle questions of paternity,
– identify victims of accidents, and
– probe the origin of nonhuman materials.
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RFLPs can be used to detect differences in DNA
sequences
 A single nucleotide polymorphism (SNP) is a
variation at a single base pair within a genome.
 Restriction fragment length polymorphism
(RFLP) is a change in the length of restriction
fragments due to a SNP that alters a restriction
site.
 RFLP analysis involves
– producing DNA fragments by restriction enzymes and
– sorting these fragments by gel electrophoresis.
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DNA Sequencing
 DNA replication that is
terminated in specific
locations
 Use DNA primer that is
complementary to a
section of the genome
to be sequenced
 Regular
deoxyribonucleotides
DNA Sequencing
 Use
dideoxyribonucleotides
tagged (radioactive or
fluorescent) to terminate
reactions
DNA Sequencing
 Nowadays an automoatic scanner reads the
sequences – each base has a different color
 Before that radioactive probes run on a gel was read
manually
GENETICALLY MODIFIED
ORGANISMS
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Recombinant cells and organisms can
mass-produce gene products
 Recombinant cells and organisms constructed by
DNA technologies are used to manufacture many
useful products, chiefly proteins.
 Bacteria are often the best organisms for
manufacturing a protein product because bacteria
– have plasmids and phages available for use as genecloning vectors,
– can be grown rapidly and cheaply,
– can be engineered to produce large amounts of a
particular protein, and
– often secrete the proteins directly into their growth
medium.
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Recombinant cells and organisms can
mass-produce gene products
 Yeast cells
– are eukaryotes,
– have long been used to make bread and beer,
– can take up foreign DNA and integrate it into their
genomes,
– have plasmids that can be used as gene vectors, and
– are often better than bacteria at synthesizing and
secreting eukaryotic proteins.
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12.6 Recombinant cells and organisms can
mass-produce gene products
 Mammalian cells must be used to produce
proteins with chains of sugars. Examples include
– human erythropoietin (EPO), which stimulates the
production of red blood cells,
– factor VIII to treat hemophilia, and
– tissue plasminogen activator (TPA) used to treat heart
attacks and strokes.
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Table 12.6_1
Table 12.6_2
Recombinant cells and organisms can
mass-produce gene products
 Pharmaceutical researchers are currently exploring
the mass production of gene products by
– whole animals or
– plants.
 Recombinant animals
– are difficult and costly to produce and
– must be cloned to produce more animals with the same
traits.
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CONNECTION: DNA technology has changed
the pharmaceutical industry and medicine
 Products of DNA technology are already in use.
– Therapeutic hormones produced by DNA technology
include
– insulin to treat diabetes and
– human growth hormone to treat dwarfism.
– DNA technology is used to
– test for inherited diseases,
– detect infectious agents such as HIV, and
– produce vaccines, harmless variants (mutants) or derivatives
of a pathogen that stimulate the immune system.
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Figure 12.7B
CONNECTION: Genetically modified organisms
are transforming agriculture
 Genetically modified (GM) organisms contain
one or more genes introduced by artificial means.
 Transgenic organisms contain at least one gene
from another species.
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CONNECTION: Genetically modified organisms
are transforming agriculture
 The most common vector used to introduce new
genes into plant cells is
– a plasmid from the soil bacterium Agrobacterium
tumefaciens and
– called the Ti plasmid.
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Figure 12.8A_s1
Agrobacterium
tumefaciens
DNA containing the
gene for a desired trait
Ti
plasmid
Restriction
site
1
The gene is
inserted into
the plasmid.
Recombinant
Ti plasmid
Figure 12.8A_s2
Agrobacterium
tumefaciens
DNA containing the
gene for a desired trait
Ti
plasmid
Restriction
site
1
The gene is
inserted into
the plasmid.
Plant cell
2
Recombinant
Ti plasmid
The recombinant
plasmid is
introduced into
a plant cell.
DNA carrying
the new gene
Figure 12.8A_s3
Agrobacterium
tumefaciens
DNA containing the
gene for a desired trait
Ti
plasmid
Restriction
site
1
The gene is
inserted into
the plasmid.
Plant cell
2
Recombinant
Ti plasmid
The recombinant
plasmid is
introduced into
a plant cell.
DNA carrying
the new gene
3
The plant cell
grows into
a plant.
A plant
with the
new trait
CONNECTION: Genetically modified organisms
are transforming agriculture
 GM plants are being produced that
– are more resistant to herbicides and pests and
– provide nutrients that help address malnutrition.
 GM animals are being produced with improved
nutritional or other qualities.
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Figure 12.8B
Genetically modified organisms raise concerns
about human and environmental health
 Scientists use safety measures to guard against
production and release of new pathogens.
 Concerns related to GM organisms include the
potential
– introduction of allergens into the food supply and
– spread of genes to closely related organisms.
 Regulatory agencies are trying to address the
– safety of GM products,
– labeling of GM produced foods, and
– safe use of biotechnology.
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CONNECTION: Gene therapy may someday
help treat a variety of diseases
 Gene therapy aims to treat a disease by
supplying a functional allele.
 One possible procedure is the following:
1. Clone the functional allele and insert it in a retroviral
vector.
2. Use the virus to deliver the gene to an affected cell
type from the patient, such as a bone marrow cell.
3. Viral DNA and the functional allele will insert into the
patient’s chromosome.
4. Return the cells to the patient for growth and division.
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CONNECTION: Gene therapy may someday
help treat a variety of diseases
 Gene therapy is an
– alteration of an afflicted individual’s genes and
– attempt to treat disease.
 Gene therapy may be best used to treat disorders
traceable to a single defective gene.
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Figure 12.10
Cloned gene
(normal allele)
1 An RNA version of
a normal human
gene is inserted
into a retrovirus.
RNA genome of virus
Retrovirus
2 Bone marrow cells
are infected with
the virus.
3 Viral DNA carrying the
human gene inserts into
the cell’s chromosome.
Bone marrow
cell from the patient
4 The engineered
cells are injected
into the patient.
Bone
marrow
Figure 12.10_1
Cloned gene
(normal allele)
1 An RNA version of
a normal human
gene is inserted
into a retrovirus.
RNA genome of virus
Retrovirus
Figure 12.10_2
2 Bone marrow cells
are infected with
the virus.
3 Viral DNA carrying the
human gene inserts into
the cell’s chromosome.
Bone marrow
cell from the patient
4 The engineered
cells are injected
into the patient.
Bone
marrow
CONNECTION: Gene therapy may someday
help treat a variety of diseases
 The first successful human gene therapy trial in
2000
– tried to treat ten children with SCID (severe combined
immune deficiency),
– helped nine of these patients, but
– caused leukemia in three of the patients, and
– resulted in one death.
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CONNECTION: Gene therapy may someday
help treat a variety of diseases
 The use of gene therapy raises many questions.
– How can we build in gene control mechanisms that
make appropriate amounts of the product at the right
time and place?
– How can gene insertion be performed without harming
other cell functions?
– Will gene therapy lead to efforts to control the genetic
makeup of human populations?
– Should we try to eliminate genetic defects in our
children and descendants when genetic variety is a
necessary ingredient for the survival of a species?
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CONNECTION: DNA profiling has provided
evidence in many forensic investigations
 DNA profiling is used to
– determine guilt or innocence in a crime,
– settle questions of paternity,
– identify victims of accidents, and
– probe the origin of nonhuman materials.
© 2012 Pearson Education, Inc.
CONNECTION: The Human Genome Project
revealed that most of the human genome
does not consist of genes
 The goals of the Human Genome Project (HGP)
included
– determining the nucleotide sequence of all DNA in the
human genome and
– identifying the location and sequence of every human
gene.
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CONNECTION: The Human Genome Project
revealed that most of the human genome
does not consist of genes
 Results of the Human Genome Project indicate that
– humans have about 20,000 genes in 3.2 billion
nucleotide pairs,
– only 1.5% of the DNA codes for proteins, tRNAs, or
rRNAs, and
– the remaining 98.5% of the DNA is noncoding DNA
including
– telomeres, stretches of noncoding DNA at the ends of
chromosomes, and
– transposable elements, DNA segments that can move or be
copied from one location to another within or between
chromosomes.
© 2012 Pearson Education, Inc.
Figure 12.18
Exons (regions of genes coding for protein
or giving rise to rRNA or tRNA) (1.5%)
Repetitive
DNA that
includes
transposable
elements
and related
sequences
(44%)
Introns and
regulatory
sequences
(24%)
Unique
noncoding
DNA (15%)
Repetitive
DNA
unrelated to
transposable
elements
(15%)
Proteomics is the scientific study of the full set of
proteins encoded by a genome
 Proteomics
– is the study of the full protein sets encoded by
genomes and
– investigates protein functions and interactions.
 The human proteome includes about 100,000
proteins.
 Genomics and proteomics are helping biologists
study life from an increasingly holistic approach.
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You should now be able to
1. Explain how plasmids are used in gene cloning.
2. Explain how restriction enzymes are used to “cut
and paste” DNA into plasmids.
3. Explain how plasmids, phages, and BACs are used
to construct genomic libraries.
4. Explain how a cDNA library is constructed and how
it is different from genomic libraries constructed
using plasmids or phages.
5. Explain how a nucleic acid probe can be used to
identify a specific gene.
© 2012 Pearson Education, Inc.
You should now be able to
6. Explain how different organisms are used to massproduce proteins of human interest.
7. Explain how DNA technology has helped to
produce insulin, growth hormone, and vaccines.
8. Explain how genetically modified (GM) organisms
are transforming agriculture.
9. Describe the risks posed by the creation and
culturing of GM organisms and the safeguards that
have been developed to minimize these risks.
© 2012 Pearson Education, Inc.
You should now be able to
10. Describe the benefits and risks of gene therapy in
humans. Discuss the ethical issues that these
techniques present.
11. Describe the basic steps of DNA profiling.
12. Explain how PCR is used to amplify DNA
sequences.
13. Explain how gel electrophoresis is used to sort
DNA and proteins.
14. Explain how short tandem repeats are used in
DNA profiling.
© 2012 Pearson Education, Inc.
You should now be able to
15. Describe the diverse applications of DNA
profiling.
16. Explain how restriction fragment analysis is
used to detect differences in DNA sequences.
17. Explain why it is important to sequence the
genomes of humans and other organisms.
18. Describe the structure and possible functions of
the noncoding sections of the human genome.
19. Explain how the human genome was mapped.
© 2012 Pearson Education, Inc.
You should now be able to
21. Compare the fields of genomics and proteomics.
22. Describe the significance of genomics to the
study of evolutionary relationships and our
understanding of the special characteristics of
humans.
© 2012 Pearson Education, Inc.