Transcript The Ethics of Genomics

The Ethics of Genomics
Are GMOs Bad?
Is Genetic Testing Good?
How Should the Public Be Informed
of New Discoveries?
Should We Clone Humans?
GMOs- Genetically Modified
Organisms
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Is the modification of genomes intrinsically
wrong or enormously beneficial?
Many choose to evaluate this question on a
case-by-case basis
Golden Rice
Biological Plastics
Pharmaceutical Produce
Sterile Fruit
Pest-Resistant Plants
Xenotransplants
Golden Rice
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Rice is the staple food for 124 million people
Many of these same people suffer from a
vitamin A deficiency- which causes blindness
Vitamin pills are not feasible in countries
which lack $ and infrastructure
In Jan 2000, rice was transformed with 3
genes which allow it to make b-carotene
Two of these genes came from daffodil and
one came from bacteria
Testing is being performed in the Philippines,
Africa, China, India, and Latin America
So, What’s the Controversy?
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All commercial rights to Golden Rice has been
transferred to Syngenta, the world’s largest
agribusiness
Syngenta has promised to provide Golden Rice
to all subsistence farmers free of charge
Organizations such as Greenpeace believe this
is a ploy to introduce more GMOs into
developing countries where resistance is limited
Syngenta claims that only strains consumed
within the developing country will be bred, not
ones which could then be sold in the West
Biological Plastics
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Plastic is usually made from petroleum
products
PHA (polyhydroxyalkanoate) is a naturally
occurring form of polyester
It was 1st described in 1925 by Lemoigne
PHA uses renewable resources and is
biodegradable
GMOs have been modified to produce PHA
Metabolix is one company working with
GMOs in this way
Pharmaceutical Produce
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Edible plants have been engineered to
deliver vaccinations
Arntzen and colleagues produced the 1st
prescription potato
Unfortunately, raw potatoes work best to
deliver medicine- cooked ones lose 50% of
their potency
Increased consumption may make up for this
loss
Additional trials are underway with bananas
Sterile Fruit
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In 1997, a patent was granted for “Terminator”
technology
This can render GM seeds sterile so that they
cannot be re-planted by farmers
The technology was designed to protect the
investments of biotech companies
Monsanto has acquired the rights to this
technology
Many farmers, especially subsistence ones, replant the seeds from the previous crop
It is feared that companies may monopolize
the world’s food supply using this technology
Pest-Resistant Plants
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Bacillus subtilis toxin (BT) has been
incorporated into plants
The use of this natural pesticide should
reduce the amount of chemicals used
It is feared that the BT gene could be
transferred to other plants via lateral transfer
Initial claims of BT being transferred to milk
weed and killing monarch butterflies have
been unfounded
Like antibiotic resistance, some insects have
become resistant to BT
Xenotransplants
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Organs are taken from one species and put into
another
In 1984, a baboon’s heart was transplanted into
Baby Fae, who lived 20 days
Pigs are commonly used as sources of adult
organs
Nextran is one company which genetically
engineers pigs to serve as better donors
The plasma membranes of pig cells have been
inserted with human proteins to reduce rejection
Most concerns center on disease transmission
Why Pigs?
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they grow to be the size of a large human and
share certain physiological and anatomical
aspects with humans
they are domesticated and are easy to breed
they have large litters and grow rapidly
The first genetically engineered pig was born
in 1992
By 1994, hundreds of these pigs had been
produced for organ-transplant research
In 2003, it was announced that a pig gene that
contributes to human rejection of porcine
organs had been knocked-out.
Why Not Pigs?
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A number of porcine diseases have the potential to
infect humans
Pigs are known to have PERVs (porcine endogenous
retroviruses)
PERVs have been shown to be able to infect
immunodeficient mice and human cells in culture
It is still unknown whether there are diseases which can
be passed between pigs and humans
As research continues, thousands wait to receive organ
transplants; about 25-30% of patients waiting for heart
or lung transplants die before suitable organs became
available to them
Could human cloning be an answer to this shortage?
Ice-Nucleation Bacteria
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The damage caused by frost injury in this
country has been estimated to exceed $1
billion/year
In nature, the formation of ice crystals on plants
is often triggered by the growth of bacteria on
the outside of these plants
Some bacteria have proteins on their surfaces
that are particularly effective triggers of icenucleation
In the absence of these bacteria, plants can
reach an internal temperature of -5oC without
freezing
How To Keep Plants From Freezing:
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warm the air around them or insulate the crops
spray bactericides on the crops to kill the bacteria
spray the crops with bacteria which inhibit the growth of
ice-nucleation bacteria
The bacteria responsible for ice-nucleation are P. syringae.
These bacteria have been genetically engineered to lack
the protein which causes ice-nucleation and are known as
ice-minus strains.
In 1983, field tests were approved for the ice-minus
bacteria. Jeremy Rifkin complained that ice-nucleation
bacteria could play a role in the climate by triggering icenucleation events in the atmosphere.
Trials of ice-minus bacteria were blocked for many years,
the first test took place in 1987.
Insertion of Modified DNA into Cells
Vectorless:
1) Biolistic delivery uses a particle gun to shoot DNA
into an organism. DNA of interest is mixed with
particles of metal such as tungsten. Widely used in
plants.
2) Microinjection into the nucleus involves the use of a
microscope and a very small needle. This method is
used on animal cells (Xenopus oocytes), and
ensures that a large proportion of cells take up the
DNA.
3) Electroporation uses a strong electric field which
forces the DNA into the cells. Used on plant and
fungal cells
4) Silicon carbide transformation simply mixes DNA with
particles which punch small holes in plant cells.
Retroviruses
Have been used in attempts to insert a copy of a gene into
bone marrow cells, the desired gene is first made into RNA
and then inserted into the retrovirus
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Limitations of this technique are:
1) Retroviruses can only infect dividing cells, certain body
cells (ie. nerves) do not divide
2) Retroviruses insert themselves at random into human
chromosomes- it is not possible to control where they will
be inserted
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gene may not be effective as normal if inserted into the
wrong area
b) gene may be inserted into tumor-suppressor genes and
cause cancer
Adenoviruses
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Do not insert their DNA into host chromosomes
Have been used to attempt gene therapy for CF
Descendents of GM cells do not carry the CF gene
The treatment must be repeated every few months,
but there is no risk of cancer
Agrobacterium
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Causes crown gall in plants, a disease consisting of
tumors on the stalk of a plant
The bacterium enters wounds on plants and inserts
part of a plasmid (Ti) into the host DNA
Scientists can insert a desired gene into the Ti plasmid
and infect plants with this recombinant plasmid
History of Biotech: the early years
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10,000-9,000 B.C. (Mesopotamia & Canaan) D. of dogs
9,000-8,000 B.C. (Iran & Afghanistan) D. of goats and
sheep; (Canaan) D. of emmer wheat and barley
8,000-7,000 B.C. (Peru) D. of potatoes and beans,
(Indonesia) rice and (North America) pumpkins
7,000-6,000 B.C. (East Asia & China) D. of pig and
water buffalo, (South Asia) chicken, (Turkey) cows,
(Syria) einkorn wheat, (Turkey) macaroni, (New Guinea)
sugarcane, (Indonesia) yams, bananas and coconuts,
(Asia) flax, and (Mexico) maize and peppers; (Egypt)
beer first made from yeast
3,000 B.C. (Iran) Breeding records of domesticated
donkeys recorded on stone tablets
2,000 B.C. (Sumaria) 19 brands of beer available
300 B.C. Aristotle: concept of speciation
History of Biotech: the modern era
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1970’s- Restriction enzymes discovered, methods to
determine the sequence of DNA
1975- Conference in Asilomar, CA to set guidelines for
genetic engineering
1983- PCR developed
1995- H. influenzae 1st organism to have its entire
genome sequenced
1996- “Dolly” the sheep becomes first mammal to be
cloned by nuclear transfer
1998- Mice and cows cloned
1999- Monkeys cloned, Jesse Gelsinger becomes 1st
death attributed to gene therapy
2003- The human genome sequenced; Dolly dies at
an early age
Traditional Biotech vs. GMOs
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species which are crossed in traditional
biotechnology are always closely related, this is not
so in genetic engineering
the pace of change in traditional biotechnology is
much slower than that of genetic engineering,
working on a scale of years rather than weeks
traditional biotechnology has been applied on a
relatively small number of species, such as crop
plants, farm animals and yeast. Genetic engineering
is more ambitious in scope and seeks to change
these, as well as other, organisms such as those
involved in sewage disposal, pollution control and
drug production.
Is Genetic Testing Good?
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Life Insurance
Universal Screening
Genomic Diversity Banks
Who Will Benefit the Most?
At the inception of the HGP in 1990, ELSI
was formed to study Ethical Legal and
Social Issues of genomics
ELSI
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Privacy and Fairness in the Use and
Interpretation of Genetic Information
Clinical Integration of New Genetic
Technologies
(examines impact of genetic testing on
individuals, families, and society)
Issues Surrounding Genetics Research
(the design, conduct, participation in, and
reporting of genetics research)
Public and Professional Education
Ethics of Genetic Testing
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When a new disease-associated gene is
discovered, a genetic test may soon follow
Many people in positions of authority
believe in genetic determinism, that all
human traits are encoded in DNA, this is
an oversimplification of the truth
Is genetic testing a new form of eugenics?
Who has the right to know the results of
your test?
Who has the right to obtain your DNA for
genetic testing?
Screening for G6PD Deficiency
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In addition to sensitivity to fava beans, deficiency in
G6PD puts employees exposed to certain oxidizing
agents at higher risk
A simple and inexpensive test can detect G6PD
deficiency
A number of companies have screened workers for
this deficiency as part of their hiring process when th
work entails exposure to oxidizing agents
It could be argued that this practice provides a type o
discrimination, but companies argue that they are
simply fulfilling their legal and moral obligation to
prevent injuries and damage to worker health
Life Insurance and
Genetic Testing
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British life insurance companies can use
data from 8 genetic tests, including breast
cancer, colon cancer, Alzheimer’s, and (as
of 2000) Huntington’s disease
In the latter case, people who test positive
can be denied insurance (with the
exception of the basic life insurance
needed to buy a house in the U.K.)
Shouldn’t those who are free of a disease
pay lower rates than those who test
positive?
U.S. Insurance Providers
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Some have recommended legislation be passed that
would prevent insurance companies from
discriminating on the basis of genetic information.
Some of the main stipulations of this proposal are:
IPs should be prohibited from using genetic
information to deny or limit any coverage
IPs should be prohibited from establishing differential
rates or premium payments based on genetic
information
IPs should be prohibited from requesting or requiring
collection or disclosure of genetic information
IPs and other holders of genetic information should
be prohibited from releasing genetic information
without prior consent of the individual
Utility of Genetic Tests
A number of factors must be considered to decide
whether an individual test is beneficial to the
patient
Universal Screening for a Disease
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Every pregnant woman in America is informed
of the availability of a test for Cystic Fibrosis
This is the 1st of nearly 400 genetic tests to be
implemented nationally
CF is the most common genetic disease for
Caucasians but not other populations
CF occurs in 1 out of 2,500 Caucasian births
but only 1 out of 17,000 African American ones
Moreover, the efficiency of detection is 85% in
Caucasians but ranges between 30-69% for
non-Caucasian populations
Screening for Cystic Fibrosis
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Most experts agree that a universal test for CF
does not make sense
Nevertheless, the HMO Kaiser Permanente
conducted a pilot test
They offered the test to all Caucasian patients
1st, both parents were tested- if they were
heterozygous- the fetus could be tested
About 18,000 women have been screened to
date- 90% of these have terminated their
pregnancy if the fetus was homozygous for CF
Genomic Diversity Banks
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In 1996, Kari Stefansson started a company
called deCODE
Their goal is to create genomic fingerprints for
the entire population of Iceland- 275,000
people!
Iceland is ideal for such a venture since the
majority of the population is descended from a
few European explorers and the people have
kept detailed family trees
Differences which lead to medical conditions
should be easier to find in such a population
Icelander’s Right to Privacy?
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Iceland has a single medical provider, all
records are kept in the same database
deCODE purchased the medical records and
has correlated family relationships with medical
records
Every citizen will give blood to determine a
genetic fingerprint unless they opt out
Some physicians worry that patient-physician
trust has been broken and that patients may be
less forth-coming with medical information
Estonia has expressed interest in forming
similar program
How Should the Public Be
Informed of New Discoveries?
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News media outlets tend to over-simplify
findings, but most Americans do not
understand the scientific literature
The media has recently reported on the
discovery of a: “gay gene”, “smart gene”, “fat
gene”, “worry gene”, “Alzheimer’s gene”,
“cancer gene”, and “fountain-of-youth” gene
Most of the time, the fact that these are just
one of many genes affecting a given condition
or that environmental factors exist is buried in
the story of left out completely
Should We Clone Humans?
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In 2001, a number of groups announced
that they would clone a human by 2003
However, these groups have little
credibility within the scientific community
and include the Raelian cult (who believe
life was produced by extra-terrestrials)
In Jan. of 2003 it was claimed that a clone
had been born but this is now thought to
have been a hoax
Despite this, it is likely that some group will
attempt to clone a human in the future
Arguments Against Human Cloning
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In 2001, Rudolf Jaenisch (an epigeneticist) and
Ian Wilmut (Dolly’s cloner) published a paper
called “Don’t Clone Humans!”
In it they described a number of failed attempted
to clone animals and health problems associated
with clones
In 2003, Dolly died at half the expected age
Epigenetic factors which may be altered in clones
include CpG methylation, chromatin structure,
and telomere length
Most have denounced human cloning at this time