Download Adult stem cells

Chapter 11
How Genes Are Controlled
PowerPoint® Lectures for
Campbell Essential Biology, Fourth Edition
– Eric Simon, Jane Reece, and Jean Dickey
Campbell Essential Biology with Physiology, Third Edition
– Eric Simon, Jane Reece, and Jean Dickey
Lectures by Chris C. Romero, updated by Edward J. Zalisko
© 2010 Pearson Education, Inc.
Chapter 12
DNA Technology
PowerPoint® Lectures for
Campbell Essential Biology, Fourth Edition
– Eric Simon, Jane Reece, and Jean Dickey
Campbell Essential Biology with Physiology, Third Edition
– Eric Simon, Jane Reece, and Jean Dickey
Lectures by Chris C. Romero, updated by Edward J. Zalisko
© 2010 Pearson Education, Inc.
 How can Mutations affect
different generations?
 1- I take a new experimental pill that changes the
DNA in my skin cells to make me permanently tan.
 2- I go to gym to get huge muscles.
 3- I smoke cigarettes and get lung cancer.
 4- I expose myself to gamma rays to become the
Hulk.
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 The human gene for insulin is inserted
into bacteria
 Because the genetic code is universal,
the human gene can be transcribed
and translated by the bacteria, thereby
creating large amounts of insulin.
Bacteria
l DNA
Insulin producing
Bacteria
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Human Insulin Gene
ENZYME
Transformation
An Example of Selective Breeding
Brahman cattle:
Good resistance to
heat but poor beef.
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English shorthorn
cattle: Good beef but
poor heat resistance.
Santa Gertrudis
cattle: Formed by
crossing Brahman
and English
shorthorns; has good
heat resistance and
beef.
Plant Clones
Single
cell
Root of
carrot plant
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Root cells in
growth medium
Cell division
in culture
Figure 11.12-3
Single
cell
Root of
carrot plant
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Root cells in
growth medium
Cell division
in culture
Young
plant
Figure 11.12-4
Single
cell
Root of
carrot plant
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Root cells in
growth medium
Cell division
in culture
Young
plant
Adult
plant
Figure 11.12-5
• The somatic cells of a single plant can be used to produce
hundreds of thousands of clones.
• Plant cloning
– Demonstrates that cell differentiation in plants does not cause irreversible
changes in the DNA
– Is now used extensively in agriculture
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Reproductive Cloning of Animals
• Nuclear transplantation
– Involves replacing nuclei of egg cells with nuclei from differentiated cells
– Has been used to clone a variety of animals
– Success/Efficiency rate NOT good
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• In 1997, Scottish researchers produced Dolly, a sheep, by
replacing the nucleus of an egg cell with the nucleus of an adult
somatic cell in a procedure called reproductive cloning, because
it results in the birth of a new animal.
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Remove
nucleus
from egg
cell
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Figure 11.13-1
Donor
cell
Remove
nucleus
from egg
cell
Add somatic
cell from
adult donor
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Figure 11.13-2
Donor
cell
Remove
nucleus
from egg
cell
Add somatic
cell from
adult donor
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Nucleus from
donor cell
Grow in culture
to produce an
early embryo
Figure 11.13-3
Reproductive cloning
Donor
cell
Nucleus from
donor cell
Implant embryo
in surrogate
mother
Remove
nucleus
from egg
cell
Add somatic
cell from
adult donor
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Clone of
donor is born
Grow in culture
to produce an
early embryo
Figure 11.13-4
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© 2010 Pearson Education, Inc.
Figure 11.13a
Human Cloning
• Cloning of animals
– Has heightened speculation about human cloning
– Is very difficult and inefficient
• Critics raise practical and ethical objections to human cloning.
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Cloning Pros:
 There is no better way to understand the human
genome
 Ability to produce “superhumans”
 Will all but cease the production of lab animals
 Medicinal methods will be thrusted into a new era
 Further understanding of our past (evolution)
 Organ transplant waiting lists will be no more
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Cloning Cons:
 Humans are sentient beings, they are not made to be
specimens. They are of free will
 Ability to produce “Superhumans”
 Countries could clone armies
 If humans can be cloned, it makes them property,
which can be sold. Inhumane
 If cloning is relied upon for reproduction and we lose
the ability to clone, everyone will have the same
genotype and to reproduce would be a sick twist of
inbreeding.
 If everyone has the same genotype, a disease that is
fatal for that genotype wipes out the human race
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 Cloning does NOT take into account
environmental traits or factors.
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The expression of some genotypes
depends on specific environments.
Himalayan Rabbit
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Gel Electrophoresis
 Gel electrophoresis is a technique used to
separate DNA into genes based on physical
characteristics such as size.
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Restriction Enzyme
 Cuts DNA at specific sites—depending on enzyme.
 EcoR1 cuts DNA GAATTC
 PovII cuts DNA CAGCTG
 SmaI cuts DNA CCCGGG
 StuI
cuts DNA
AGGCCT
 Alul
cuts DNA
AGCT
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Use Enzyme Fournier1 which cuts CCGG
ATCGTCGAACTGGGATCCGGTAAAGCTTTAAGGCCTTA
CGTTCCGGGAAGGTTCCGGATTAAGGCCTTAAGGTT
TCCGATCGATCGATTCGATCCGGATATCGGTAATTCG
AATTCGTGTCATCGTTACGCTTGCCGGAATTTCCGTA
TCGCCGGTTAATCTGAGACTACGGAGCATCGTAGTC
Segments are 18, 26, 11, 40, 41, 17 and 31.
So, in order, you get banding at:
11, 17, 18, 26, 31, 40, 41
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Mixture of DNA
fragments of
different sizes
Band of
longest
(slowest)
fragments
Power
source
Gel
Completed gel
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Band of
shortest
(fastest)
fragments
Figure 12.17-3
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© 2010 Pearson Education, Inc.
GMO- genetically modified organism
Organisms altered by genetic
engineering.
-genetic material changed by other than
random natural breeding.
-gene transfer-moving a gene from one
organism to another.
-these require skill and knowledge to be
carried out properly
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Agriculture
-food processors affected by genetic
engineering.
-shelf-life, storage, food-handling;
extended and simplified.
-help resist spoilage.
-plants transformed-insect,disease, and
herbicide resistant.
-animals treated engineered hormonesproduce more milk, leaner meat.
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© 2010 Pearson Education, Inc.
© 2010 Pearson Education, Inc.
• Advocates of a cautious approach are concerned that:
– Crops carrying genes from other species might harm the environment
– GM foods could be hazardous to human health
– Transgenic plants might pass their genes to close relatives in nearby wild
areas
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• In 2000, negotiators from 130 countries (including the United
States) agreed on a Biosafety Protocol that:
– Requires exporters to identify GM organisms present in bulk food
shipments
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Genetic Ethics
 Solving Crimes
 Increase/Make better crops & food
 Increased info : health, admittance
 Cloning
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Medicinal Studies
 Control Group
 Comparative results
 Cost
 Ethics
 Help 1 now or Save all later?
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• SCID is a fatal inherited disease caused by a single defective gene
that prevents the development of the immune system.
• SCID patients quickly die unless treated with:
– A bone marrow transplant or
– Gene therapy
• Since the year 2000, gene therapy has:
– Cured 22 children with inborn SCID but
– Unfortunately, caused four of the patients to develop leukemia, killing
one of these children
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Ethical Questions Raised by DNA Technology
• DNA technology raises legal and ethical questions—few of which
have clear answers.
– Should genetically engineered human growth hormone be used to
stimulate growth in HGH-deficient children?
– Do we have any right to alter an organism’s genes—or to create new
organisms?
– Should we try to eliminate genetic defects in our children and their
descendants?
– Should people use mail-in kits that can tell healthy people their relative
risk of developing various diseases?
© 2010 Pearson Education, Inc.
Reproductive cloning
Donor
cell
Nucleus from
donor cell
Implant embryo
in surrogate
mother
Clone of
donor is born
Therapeutic cloning
Remove
nucleus
from egg
cell
Add somatic
cell from
adult donor
© 2010 Pearson Education, Inc.
Grow in culture
to produce an
early embryo
Remove
embryonic
stem cells from
embryo and
grow in culture
Induce stem
cells to form
specialized
cells for
therapeutic use
Figure 11.13-5
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© 2010 Pearson Education, Inc.
Embryonic Stem Cells
• Embryonic stem cells (ES cells)
– Are derived from blastocysts
– Can give rise to specific types of differentiated cells
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Adult Stem Cells
• Adult stem cells
– Are cells in adult tissues
– Generate replacements for nondividing differentiated cells
• Unlike embryonic ES cells, adult stem cells
– Are partway along the road to differentiation
– Usually give rise to only a few related types of specialized cells
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Adult stem
cells in
bone marrow
Blood cells
Nerve cells
Cultured
embryonic
stem cells
Heart muscle cells
Different culture
conditions
Different types of
differentiated cells
Figure 11.15