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Chapter 12
DNA Technology and
Genomics
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DNA and Crime Scene Investigations
• Many violent crimes go unsolved
o For lack of enough evidence
• If biological fluids are left at a crime scene
o DNA can be isolated from them
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• DNA fingerprinting is a set of laboratory procedures
o That determines with near certainty whether two
samples of DNA are from the same individual
o That has provided a powerful tool for crime scene
investigators
Investigator at one
of the crime scenes
(above), Narborough,
England (left)
BACTERIAL PLASMIDS AND GENE CLONING0
12.1 Plasmids are used to customize bacteria: An
overview
• Plasmid-a small DNA molecule that is physically
separate from, and can replicate independently of, the
chromosomal DNA within a cell.
• Gene cloning is one application of DNA technology
o Methods for studying and manipulating genetic
material
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• Researchers can insert desired genes into
plasmids, creating recombinant DNA
o And insert those plasmids into bacteria
Bacterium
Cell containing gene
of interest
1 lasmid
P
isolated
2DNA
isolated
Gene
inserted
3
into plasmid
Bacterial Plasmid
chromosome
Recombinant DNA
(plasmid)
DNA
Gene of
P
4 lasmid put into interest
bacterial cell
Recombinant
bacterium
5
Cell
multiplies with
gene of interest
Copies of gene
Gene for pest
resistance
inserted into
plants
Figure 12.1
Copies of protein
Clone of cells
Gene used to alter bacteria
for cleaning up toxic waste
Protein used to
make snow form
at higher
temperature
Protein used to dissolve blood
clots in heart attack therapy
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• If the recombinant bacteria multiply into a clone
o The foreign genes are also copied
CONNECTION
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12.6 Recombinant cells and organisms can massproduce gene products
• Applications of gene cloning include
o The mass production of gene products for medical and
other uses
Table 12.6
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• Different organisms, including bacteria, yeast, and
mammals
o Can be used for this purpose
Figure 12.6
CONNECTION
12.7 DNA technology is changing the
pharmaceutical industry
• DNA technology
o Is widely used to produce medicines and to
diagnose diseases
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Therapeutic hormones
• In 1982, humulin, human insulin produced by
bacteria
o Became the first recombinant drug approved by
the Food and Drug Administration
Figure 12.7A
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Diagnosis and Treatment of Disease
• DNA technology
o Is being used increasingly in disease diagnosis
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Vaccines
• DNA technology
o Is also helping medical researchers develop
vaccines
Figure 12.7B
Vaccine
• Vaccine-a substance containing all or part
of a harmless version of a pathogen that
physicians introduce into the body to
produce immunity to disease.
CONNECTION
12.12 DNA technology is used in courts of law
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• DNA fingerprinting can help solve crimes
Defendant’s
blood
Blood from
defendant’s clothes
Figure 12.12A
Victim’s
blood
Figure 12.12B
CONNECTION
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12.13 Gene therapy may someday help treat a variety of
diseases
• Gene therapy
o Is the alteration of an afflicted individual’s genes
Cloned gene
(normal allele)
1 Insert normal gene
into virus
Viral nucleic
acid
Retrovirus
2 Infect bone marrow
cell with virus
3 Viral DNA inserts
into chromosome
Bone marrow
cell from patient
Bone
marrow
Figure 12.13
4 Inject cells
into patient
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• Gene therapy
o May one day be used to treat both genetic
diseases and nongenetic disorders
• Unfortunately, progress is slow
GENOMICS
CONNECTION
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12.15 The Human Genome Project is an ambitious
application of DNA technology
• The Human Genome Project, begun in 1990 and now
largely completed, involved
o Genetic and physical mapping of chromosomes,
followed by DNA sequencing
Figure 12.15
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• The data are providing insight into
o Development, evolution, and many diseases
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12.16 Most of the human genome does not
consist of genes
• The haploid human genome contains about 25,000
genes
o And a huge amount of noncoding DNA
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• Much of the noncoding DNA consists of repetitive
nucleotide sequences
o And transposons that can move about within the
genome
Differentiation
• Differentiation-a cell becomes specialized
in structure and function.
Cloning
• A clone is an individual created by
asexual reproduction and thus is
genetically identical to a single parent.
Nuclear Transplantation
• Nuclear Transplantation-the introduction
of a nucleus from a body cell into an egg
cell to generate an organism identical to
the nucleus donor
Donor
cell
Nucleus from
donor cell
Implant blastocyst in
surrogate mother
Remove nucleus
from egg cell
Add somatic cell
from adult donor
Clone of donor is born
(reproductive cloning)
Grow in culture to produce an
early embryo (blastocyst)
Remove embryonic
Stem cells from
blastocyst and
grow in culture
Figure 11.10
Induce stem cells to
form specialized cells
(therapeutic cloning)
Reproductive Cloning
• Reproductive cloning-the type of cloning
which results in birth of a new individual.
• Reproductive cloning of nonhuman
mammals is useful in research,
agriculture, and medicine.
Therapeutic Cloning
• Therapeutic cloning-when the major aim
is to produce embryonic stem cells for
therapeutic treatments.
• Embryonic stem cells-give rise to the
different kinds of specialized cells of the
body.
• Embryonic stem cells can perpetuate
themselves in culture and
give rise to differentiated cells.
CONNECTION
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12.17 The science of genomics compares whole
genomes
• The sequencing of many prokaryotic and
eukaryotic genomes
o Has produced data for genomics, the study of
whole genomes
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• Besides being interesting themselves
o Nonhuman genomes can be compared with the
human genome
Table 12.17
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• Proteomics
o Is the study of the full sets of proteins produced
by organisms
GENETICALLY MODIFIED ORGANISMS
CONNECTION
12.18 Genetically modified organisms are
transforming agriculture
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• Recombinant DNA technology
o Can be used to produce new genetic varieties of
plants and animals, genetically modified (GM)
organisms
Agrobacterium tumefaciens
DNA containing
gene for desired trait
Ti
plasmid
1
Insertion of gene
into plasmid using
restriction enzyme
and DNA ligase
T DNA
Plant cell
Recombinant
Ti plasmid
2
3
Introduction
Regeneration
into plant
of plant
cells in
culture
T DNA carrying new
Plant with new trait
gene within plant chromosome
Restriction
site
Figure 12.18A
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• Transgenic organisms
o Are those that have had genes from other
organisms inserted into their genomes
Figure 12.18B
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• A number of important crops and plants
o Are genetically modified
Genetically Modified Organism
• Genetically modified organisms-an organism
that has acquired one or more genes by
artificial means rather than by traditional
breeding methods.
Agricultural Applications
• To feed the planet’s hungry population,
biologists have made crop plants that are
more tolerant to environmental
conditions.
• The plants are protected from serious
damage and yield more food.
CONNECTION
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12.19 Could GM organisms harm human health or
the environment?
• Development of GM organisms
o Requires significant safety measures
Figure 12.19A
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• Genetic engineering involves risks
o Such as ecological damage from GM crops
Figure 12.19B
CONNECTION
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12.20 Genomics researcher Eric Lander discusses
the Human Genome Project
• Genomics pioneer Eric Lander
o Points out that much remains to be learned from
the Human Genome Project
Figure 12.20
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12.17 The science of genomics compares whole
genomes
• The sequencing of many prokaryotic and
eukaryotic genomes
o Has produced data for genomics, the study of
whole genomes