Transcript Human Genome Project, Gene Therapy, and Cloning

Human Genome Project,
Gene Therapy, and Cloning
Adapted from the University of Utah Genetic Science Learning Center
and The National Genome Research Institute, National Institutes of Health
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Human Genome Project Goals:
• To sequence & determine the exact order of the
nucleotides (A,C,T,G) for ALL of the DNA in a human
cell
• To determine which sections of DNA represent the
individual genes
• To store this information in databases for analysis
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How genes influence an
individual’s response to
drugs
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Gene
Therapy
Replacement of an
abnormal protein with a
normal one
Viruses are often used
because of their ability to
enter a cell’s DNA.
1. Isolate the normal sequence for a gene and package it into
a virus (vector).
2. Infect a target cell, usually the one with the illness, such as
a liver or lung cell.
3. The cell uses the normal sequence to produce the missing
protein and is thus repaired.
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Problems with Gene Therapy
• Short lived, so patients have to go through multiple
rounds
• Immune response to foreign invaders
• Problems with the viruses
• Very expensive
• Multigene disorders: disorders like heart disease, high
blood pressure, Alzheimer’s disease, diabetes are
caused by the combined effects of variations in many
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diseases.
Pedigree
• A chart shows the relationships within a
family of how a trait is passed from one
generation to the next.
Symbols used in pedigree charts
In a marriage with five children, two
daughters and three sons. The second
son is affected by the condition.
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Organizing the Pedigree Chart
• To the right is a pedigree
chart of a family showing
four generations. A total
of 20 individuals.
• Generations are identified
by Roman numerals.
Individuals in each
generation are identified
by Arabic numerals
numbered from the left.
Therefore the affected
individuals are II3, IV2
and IV3.
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Genetically Modified Products
• These are materials that the DNA has
been altered within to express different
traits.
Golden Rice
This rice has been
modified to
contain vitamin A
and beta-carotene
which are
nutrients that
many 3rd world
country
inhabitants won’t
normally get from
the foods they eat.
Recombinant Bovine Growth
Hormone
This is a genetically engineered
hormone that forces cows to make
more milk than they normally would.
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Genetically Modified Products
Cont.
Spider Silk
Large scale production of
artificial spider silk could
lead to the development of
stronger fibers for textiles,
bandages for burn victims,
and bulletproof vests.
Insulin
Mass production occurs
with the help of bacteria.
Edible Vaccine
Bt Crops
A naturally occurring soil bacteria
that produces proteins active
against certain insects.
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What is Cloning?
• Cloning is the creation of an organism that is
the EXACT genetic copy of the mother
• Identical twins are natural clones, they share
100% of their DNA
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How do you clone an organism?
1. Remove the nucleus from an egg cell and a
regular cell from a donor.
2. Fuse the enucleated cell with a regular cell (that
still has its nucleus) by electric shock
3. The new fused cell begins dividing, just as a
fertilized egg would.
4. The embryo is placed in the uterus of a surrogate
mother and allowed to develop normally.
5. The surrogate mother gives birth to a genetic
clone of the original egg cell donor donor!
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Why Might We Want to Clone?
• For medical purposes:
– Cloning stem cells for researchstem cells may be used to
repair damaged or diseased
tissues and organs
– Large populations of genetically
engineered cloned animals may
be able to produce drugs or
proteins for medicine-process
called “pharming”
• Revive endangered or extinct
species
– Extinct not likely
– Endangered possible but
no success yet
• Any reason to clone a
human?
– Help infertile couples
have children?
– “Replace” a deceased
child?
– Even if clones start out
alike, there are many
factors that occur after
fertilization that lead to
differences in
appearance.
In December ’01 the first
domestic pet ever to be cloned
was born – kitten named CC,
next to her is her genetic donor.
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