Cells: A Primer
- What is a stem cell?
- Introduction to
Why Clone Human
Clone or not to
The Ethical Question
Using cloned human
Cells: A Primer
primer presents background information on stem cells. It includes an
explanation of what stem cells are; what pluripotent stem cells are; how
pluripotent stem cells are derived; why pluripotent stem cells are
important to science; why they hold such great promise for advances in
health care; and what adult stem cells are.
Recent published reports on the
isolation and successful culturing of the first human pluripotent stem
cell lines have generated great excitement and have brought biomedical
research to the edge of a new frontier. The development of these human
pluripotent stem cell lines deserves close scientific examination,
evaluation of the promise for new therapies, and prevention strategies,
and open discussion of the ethical issues.
In order to understand the importance of this discovery as well as the
related scientific, medical, and ethical issues, it is absolutely
essential to first clarify the terms and definitions.
- abbreviation for deoxyribonucleic acid which makes up genes.
- a functional unit of heredity which is a segment of DNA located in a
specific site on a chromosome. A gene directs the formation of an enzyme
or other protein.
- cell of the body other than egg or sperm.
Somatic cell nuclear transfer
- the transfer of a cell nucleus from a somatic cell into an egg from
which the nucleus has been removed.
- cells that have the ability to divide for indefinite periods in
culture and to give rise to specialized cells.
-capable of giving rise to most tissues of an organism.
- having unlimited capability. Totipotent cells have the capacity to
specialize into extraembryonic membranes and tissues, the embryo, and
all postembryonic tissues and organs.
- Transplant of healthy heart
muscle cells could provide new hope for patients with chronic heart
disease whose hearts can no longer pump adequately. The hope is to
develop heart muscle cells from human pluripotent stem cells and
transplant them into the failing heart muscle in order to augment the
function of the failing heart. Preliminary work in mice and other
animals has demonstrated that healthy heart muscle cells transplanted
into the heart successfully repopulate the heart tissue and work
together with the host cells. These experiments show that this type of
transplantation is feasible.
- In the many individuals who
suffer from Type I diabetes, the production of insulin by specialized
pancreatic cells, called islet cells, is disrupted. There is evidence
that transplantation of either the entire pancreas or isolated islet
cells could mitigate the need for insulin injections. Islet cell lines
derived from human pluripotent stem cells could be used for diabetes
research and, ultimately, for transplantation.
While this research shows
extraordinary promise, there is much to be done before we can realize
these innovations. Technological challenges remain before these
discoveries can be incorporated into clinical practice. These
challenges, though significant, are not insurmountable.
First, we must do the basic
research to understand the cellular events that lead to cell
specialization in the human, so that we can direct these pluripotent
stem cells to become the type(s) of tissue needed for transplantation.
Second, before we can use these
cells for transplantation, we must overcome the well-known problem of
immune rejection. Because human pluripotent stem cells derived from
embryos or fetal tissue would be genetically different from the
recipient, future research would need to focus on modifying human
pluripotent stem cells to minimize tissue incompatibility or to create
tissue banks with the most common tissue-type profiles.
The use of somatic cell nuclear
transfer (SCNT) would be another way to overcome the problem of tissue
incompatibility for some patients. For example, consider a person with
progressive heart failure. Using SCNT, the nucleus of virtually any
somatic cell from that patient could be fused with a donor egg cell from
which the nucleus had been removed. With proper stimulation the cell
would develop into a blastocyst: cells from the inner cell mass could be
taken to create a culture of pluripotent cells. These cells could then
be stimulated to develop into heart muscle cells. Because the vast
majority of genetic information is contained in the nucleus, these cells
would be essentially identical genetically to the person with the
failing heart. When these heart muscle cells were transplanted back into
the patient, there would likely be no rejection and no need to expose
the patient to immune-suppressing drugs, which can have toxic effects.
Adult Stem Cells
As noted earlier, multipotent
stem cells can be found in some types of adult tissue. In fact, stem
cells are needed to replenish the supply cells in our body that normally
wear out. An example, which was mentioned previously, is the blood stem
Multipotent stem cells have not
been found for all types of adult tissue, but discoveries in this area
of research are increasing. For example, until recently, it was thought
that stem cells were not present in the adult nervous system, but, in
recent years, neuronal stem cells have been isolated from the rat and
mouse nervous systems. The experience in humans is more limited. In
humans, neuronal stem cells have been isolated from fetal tissue and a
kind of cell that may be a neuronal stem cell has been isolated from
adult brain tissue that was surgically removed for the treatment of
Do adult stem cells have
the same potential as pluripotent stem cells?
Until recently, there was little
evidence in mammals that multipotent cells such as blood stem cells
could change course and produce skin cells, liver cells or any cell
other than a blood stem cell or a specific type of blood cell; however,
research in animals is leading scientists to question this view.
In animals, it has been shown
that some adult stem cells previously thought to be committed to the
development of one line of specialized cells are able to develop into
other types of specialized cells. For example, recent experiments in
mice suggest that when neural stem cells were placed into the bone
marrow, they appeared to produce a variety of blood cell types. In
addition, studies with rats have indicated that stem cells found in the
bone marrow were able to produce liver cells. These exciting findings
suggest that even after a stem cell has begun to specialize, the stem
cell may, under certain conditions, be more flexible than first thought.
At this time, demonstration of the flexibility of adult stem cells has
been only observed in animals and limited to a few tissue types.
Why not just pursue
research with adult stem cells?
Research on human adult stem
cells suggests that these multipotent cells have great potential for use
in both research and in the development of cell therapies. For example,
there would be many advantages to using adult stem cells for
transplantation. If we could isolate the adult stem cells from a
patient, coax them to divide and direct their specialization and then
transplant them back into the patient, it is unlikely that such cells
would be rejected. The use of adult stem cells for such cell therapies
would certainly reduce or even avoid the practice of using stem cells
that were derived from human embryos or human fetal tissue, sources that
trouble many people on ethical grounds.
While adult stem cells hold real
promise, there are some significant limitations to what we may or may
not be able to accomplish with them. First of all, stem cells from
adults have not been isolated for all tissues of the body. Although many
different kinds of multipotent stem cells have been identified, adult
stem cells for all cell and tissue types have not yet been found in the
adult human. For example, we have not located adult cardiac stem cells
or adult pancreatic islet stem cells in humans.
Secondly, adult stem cells are
often present in only minute quantities, are difficult to isolate and
purify, and their numbers may decrease with age. For example, brain
cells from adults that may be neuronal stem cells have only been
obtained by removing a portion of the brain of epileptics, not a trivial
Any attempt to use stem cells
from a patient's own body for treatment would require that stem cells
would first have to be isolated from the patient and then grown in
culture in sufficient numbers to obtain adequate quantities for
treatment. For some acute disorders, there may not be enough time to
grow enough cells to use for treatment. In other disorders, caused by a
genetic defect, the genetic error would likely be present in the
patient's stem cells. Cells from such a patient may not be appropriate
for transplantation. There is evidence that stem cells from adults may
have not have the same capacity to proliferate as younger cells do. In
addition, adult stem cells may contain more DNA abnormalities, caused by
exposure to daily living, including sunlight, toxins, and by expected
errors made in DNA replication during the course of a lifetime. These
potential weaknesses could limit the usefulness of adult stem cells.
Research on the early stages of
cell specialization may not be possible with adult stem cells since they
appear to be farther along the specialization pathway than pluripotent
stem cells. In addition, one adult stem cell line may be able to form
several, perhaps 3 or 4, tissue types, but there is no clear evidence
that stem cells from adults, human or animal, are pluripotent. In fact,
there is no evidence that adult stem cells have the broad potential
characteristic of pluripotent stem cells. In order to determine the very
best source of many of the specialized cells and tissues of the body for
new treatments and even cures, it will be vitally important to study the
developmental potential of adult stem cells and compare it to that of
pluripotent stem cells.
Given the enormous promise of
stem cells to the development of new therapies for the most devastating
diseases, it is important to simultaneously pursue all lines of
research. Science and scientists need to search for the very best
sources of these cells. When they are identified, regardless of their
sources, researchers will use them to pursue the development of new cell
The development of stem cell
lines, both pluripotent and multipotent, that may produce many tissues
of the human body is an important scientific breakthrough. It is not too
unrealistic to say that this research has the potential to revolutionize
the practice of medicine and improve the quality and length of life.
1 Michael Shamblott, et
al, Derivation of pluripotent stem cells from cultured human
primordial germ cells. PNAS, 95: 13726-13731, Nov. 1998.
James Thomson, et al,
Embryonic stem cell lines derived from human blastocysts. Science,
282: 1145-1147, Nov. 6, 1998.
ขณะนี้การศึกษา DNA ทั้งระบบ
Amina Ali and Owen Wood
CBC News Online, March 2001
March 2001, three scientists gathered in Rome to say they're going ahead
with human cloning, no matter what anyone says.
Dolly, the world's most famous clone
Their intentions seem good
they want to help infertile couples have children.
"Some people say we are
going to clone the world, but this isn't true," Italian Severino
Antinori, one of the doctors, said at a news conference. "We're
talking science, we're not here to create a fuss."
The team plans to combine cells
(from either the man or the woman) with one of the woman's eggs, which
has been stripped of its genetic material. When the cells form an
embryo, the scientists would implant the embryo in the woman's uterus.
The embryo would then take its "natural" course and develop
into a fetus and then a baby a baby that would have only one
idea that we may one day clone a human being
Oregon scientists cloned a monkey
has been a part of science fiction and scientific debate for
However, it wasn't until 1997,
when a team in Scotland announced it had cloned the first adult mammal,
the now-famous Dolly the sheep, that the world really changed the way it
thought about human cloning. Those who were previously asking whether it
could be done were now asking when it would be done.
But there's still the question of
whether it should be done. And the ethical issues that surround
human cloning can be as complicated as the science itself.
On the one side, there are religious
groups and other organizations that say human cloning is wrong. Period.
Sweater knit from cloned Dolly's wool
Some are against cloning for the
same reason they're against abortion and euthenasia because all
human life is valuable and destroying embryos is equal to murder. (Some
scientists want to use embryos in medical research because they contain
what are called "stem cells." Stem cells are cells that
haven't matured to perform specialized functions, which means they still
can be programmed to do anything, perfect for cloning.)
This is just one of the
There are also those anti-cloning
advocates who say we shouldn't allow human cloning because it infringes
on one of the things we value most, our individuality.
There are social implications, too.
What if someone
Einsteins for all?
cloned Albert Einstein or Joan of Arc or even someone they knew, like
their dead child or parent? What kind of life would that person have
trying to live up to the expectation that they will become as
accomplished or do the same things as their genetic counterpart?
And then there are those who say
allowing cloning would make way for the Frankenstein-like eugenics
projects or the vast armies of genetically engineered soldiers that you
see in the movies or read about in comic books.
This is not to say these
arguments should be taken lightly. In fact, the international community
has taken human cloning very seriously. Of those countries that have
adopted laws to deal with reproductive technologies, the majority
France, Germany and Australia for example have chosen to outlaw
human cloning altogether to avoid such disasters.
The United States was one of the
first to react to the Dolly announcement with President Bill Clinton
banning the use of federal funds for human cloning research. The U.S.
still has no national law to prevent private companies from doing such
work, though it is illegal in some states.
Canada has no
cloning laws either.
Pigs have also been succesfully cloned
Cloning laws would fall under the
same act that would cover other reproductive technologies, such as in
vitro fertilization, sperm donation and genetic manipulation.
In 1989, the federal government
created a Royal Commission to look at new reproductive technologies,
which resulted in the government placing a voluntary moratorium on human
embryo cloning. But so far, attempts to pass an anti-cloning law have
That's partly because of who
makes up the other side the argument: the scientists who say we
shouldn't be so quick to dismiss the benefits of human cloning.
Human cloning doesn't necessarily
mean duplicating entire people. It also includes cloning parts of
humans, cells, for example, that would no doubt be a great boost to
People with severe burns could
grow back their own skin. People who need a new organ could get one
that's guaranteed to be genetically compatible. And what about growing
entire new limbs to replace those that have been severed in an accident?
The potential for human cloning
is so great, scientists say it would be premature to stop research now,
especially seeing as the world is just beginning to understand the
possible applications of the technology.
This is why Britain, which had
earlier passed a law banning human cloning, announced in January 2001
that it would now allow scientists to clone human embryos for medical
research. The embryos must be destroyed by the time they are 14 days
old, before the cells begin to change and form specific parts of the
In December 1998, scientists at
the Infertility Clinic at Kyeonghee University in South Korea announced
they had cloned the world's first human embryo. The team allowed the
embryo to divide itself into four cells, the stage when a test tube
embryo is usually placed back in the uterus where it develops into a
fetus, before destroying it. Their goal is to clone genetically
identical organs for human transplant.
matter what governments do to prevent human
Britain destroys human embryos after 14 days
cloning, and no matter what position you take on the issue, it's hard to
ignore the reality that there are already people out there trying to be
the first to clone a human being.
One group working in the field is
the Bahamas-based Clonaid, the self-proclaimed "first human cloning
company," that says it has both the technological and financial
resources to clone a human being, and is already going ahead with
The work is being done under a
veil of secrecy. Clonaid hasn't released the name of the couple who want
to clone their child who died when she was 10 months old and it
also won't say where the cloning will be done other than that it will be
in a U.S. state where cloning is still legal. The group wants to avoid
demonstrations or possible violence by anti-cloning groups.
When Clonaid announced its
intentions in October 2000, Dr. Brigitte Boisselier, a representative of
the group, said they expected to have the first cloned baby within 18
months, which would be some time in the spring of 2002.
How to Clone a Human (Version
This is not a joke procedure,
it's the real thing. I have other pages for humor, but this page is only
for serious cloning info. This page was updated on 2/27/98 (to version
1.1) with new information from Dr. Lee Silver of Princeton University, a
noted expert on cloning. This procedure is based upon the Sheep cloning
procedure. The mouse cloning procedure seems to have worked better, so
I'll be changing this page to Version 1.2 when I get all that
information together. The two procedures are similar, but not identical.
This page provided courtesy of:
Tissue: Pure human cells of one tissue type, from the individual who
will be cloned.
- Human Tissue Culture Media:
Media in which these human cells will grow and divide.
- Minimal Human Tissue Culture
Media: Media in which cells will stop dividing, and enter a state of
"quiescence" without dying.
- Laboratory supplies: Incubator,
Sterile Hood, petri dishes, microscopes, and tools capable of removing
and implanting cellular organelles, such as the nucleus, from one cell
- Unfertilized human egg cells.
- Human Egg Cell growth media:
Media where fertilized eggs will grow and divide.
- Grow the human cells to be
cloned until you have a good supply.
- Transfer the cells to minimal
media. [For now, The Sheep Cloning Paper is a good reference for exactly
how long.] This should allow the cells to live, but they should stop
dividing and enter quiescence. This is likely the step in which the
cells lose their differentiation, and revert to a more totipotent state.
- When the cultured cells are in
the quiescent state, get an unfertilized human egg cell. Remove the
nucleus from this egg cell. Try to minimize damage done to this cell and
discard the nucleus.
- Take one of the quiescent cells
in it's entirely, and implant it inside the coat around the egg (known
as the zona pellucida) next to the egg itself.
- Electroshock the egg. [For now,
The Sheep Cloning Paper is probably a good reference for how much and
how long to electroshock.] The electroshock induces the fusion of the
two cells, so you should be able to tell when you've electroshocked
enough just by looking at the cells. The rebooting of the human genetic
program is believed to be initiated by the replacement of donor cell
protien signals by egg cell protien signals, but the electroshock might
assist in moving those protien signals across the nuclear membrane as
well. Electroporation is a common technique for moving DNA molecules
through a cellular membrane.
- Repeat the last three steps as
necessary until you have enough clones. Expect a lot of them not to
survive because of cellular damage and other mishaps. Allow the embryos
to grow and divide a few times in Human Egg Cell growth media.
- Implant the embryos in human
mothers where they will can be carried to term, and born normally.
The content of this page is
solely the responsibility of Arthur
Research in the field of
embryology and genetics has exploded over the past decade. New advances
in in vitro fertilization and genetic screening are leading to new
procedures in which human embryo cloning will be possible in the near
future. Human cloning, however, brings up many new ethical questions
that will need to be addressed by the scientific community and the
public before these advances can reach their full potential. Scientific
advances bring social changes, that many people will not be able to
accept. As with any scientific or technological advance, the most
important question that needs to be asked is whether or not the gains
out weigh the potential losses. Will human cloning become a brave new
step in fighting disease and improving the quality of life, or will it
lead to dehumanization and a new genetic underclass?
HUMAN CLONING TECHNIQUES
The procedures used in cloning
human embryos are very similar to the cloning of animal embryos, except
for the zona pellucida. Several sperm cells and mature egg cells are
gathered from donors at fertility clinics, and are combined in a petri
dish using in vitro fertilization procedures to form an embryo. In an
alternate process, already produced embryos are gathered from fertility
clinics that have embryos left over from prior in vitro clients. The
acquired embryo is placed in a petri dish and is allowed to develop into
a mass of two to eight cells. Next, a chemical solution is added that
dissolves the zona pellucida that covers the embryo. The zona pellucida
is a protective protein and polysaccharide membrane that covers the
internal contents of the embryo, and provides the necessary nutrients
for the first several cell divisions that occur within the embryo. After
the zona pellucida is dissolved the cells within the embryo are freed.
These two to eight cells are then collected by the researchers and
placed in separate petri dishes. These embryonic cells are called
blastomeres, or cells that are a part of the hollow ball of cells know
as the blastula: (Hale 83). The embryonic cells are then each coated
with an artificially produced zona pellucida: (Fackelmann 276). The
individual cells then are considered new embryos, all of which share the
same exact genetic information. In effect at this point the science has
produced multiple copies of life that could have never before existed.
Do we as a society have the moral wisdom to determine the direction or
understand the implications that this science provides our species?
These cells will divide and will eventually form a human being, if
allows to develop: (Fackelmann 276). Hall and Stillman's attempt to
produce human embryo clones was only somewhat successful. The embryos
that they used in their experiments were not able to produce human
beings, because they were double fertilized, that is fertilized by more
than one sperm cell. These embryos will eventually die during sometime
in their development because of the extra set of chromosomes donated by
the second sperm cell. The researchers removed two or more embryonic
cells from seventeen different abnormal embryos, and allowed these cells
(blastomeres) to develop into new individual embryos, using the above
stated steps. These new embryos grew and divided at the anticipated
rate, however, all eventually died before reaching the 64 cell stage. As
was stated before, from two to eight embryonic cells may be removed from
the original embryo, depending on the development of the embryo, but the
experiments completed by Hall and Stillman showed that the best results
were obtained from embryos that had divided only twice. These new
embryos reached the 32 cell stage, whereas other original embryos of
four or more cells, barely made it to the 16 cell stage. It is not known
whether these new cloned embryos would have developed further if they
had not been abnormal. Hall believes that the embryos might have
developed even further in the more natural environment of the uterus: (Kolberg
REASONS FOR EMBRYO RESEARCH
Some people may think that
biologists are cloning human embryos only to see how far they can push
the scientific envelope, but there are many legitimate reasons for
investigating cloning. Embryologists believe that research into cloning
could help improve the life of future generations. I believe that this
is the main concern of most scientists. Many biologists believe that
they have a personal duty to the improvement of society, perhaps even a
moral obligation. To this end the techniques of embryonic cloning and
alteration have been offered to society as an option for the improvement
of humanity. Doctors hope that by being able to study the multiple
embryos developed through cloning, they can determine the causes of
spontaneous abortions. Contraceptive specialists believe that if they
can determine how an embryo knows where to implant itself, they can
develop a contraceptive that would prevent embryos from implanting in
the uterus: (Watson 66). Cancer research is possibly the most important
reason for embryo cloning. Oncologists believe that embryonic study will
advance understanding of the rapid cell growth of cancer. Cancer cells
develop at approximately the same phenomenal speed as embryonic cells
do. By studying the embryonic cell growth, scientists may be able to
determine how to stop it, and also stop cancer growth in turn: (Watson
66). Another important area of embryo cloning research is embryonic stem
cell development. Stem cells are undifferentiated cells that can develop
into almost any type of cell in the body. These cells are not attacked
by a persons immune system, because of their fast development and
undifferentiated status. Many doctors believe that these stem cells
could be used in treatments for brain and nervous system damage. In
adult humans, when damage to nerve tissue takes place, the nerve tissue
does not regenerate and replace the lost tissue. However, since the stem
cells are undifferentiated they could theoretically be used to replace
the damaged cells. Human embryo cloning is needed for the implantation
of stem cells, because of the large amount of cells that would be
needed: (Marshall 1026). Genetic screening is a branch of cloning
research that is already being used in hospitals in England. Parents who
have a history of genetically inherited disease, such as cystic
fibrosis, can use embryo screening to determine if their child has
received the defective gene. Several embryos can be developed via in
vitro fertilization procedures, and then be cloned. The DNA from one of
the cloned embryos would then be removed and standard genetic testing,
using riflips, would be used to detect whether or not that embryo
contained the genetic disease. If the cloned embryo does not contain the
defective gene, then one of the other identical embryos can be used for
implantation in the parent. This would almost guarantee that the child
would be free of the genetic disease: (Marshall 1025). Perhaps a more
questionable use of cloned embryos is for spare parts. It is possible
that parents could decide to use one cloned embryo for implantation and
eventual birth of a child, and save any spares by freezing them. If the
child were to become critically sick, and need a bone marrow transplant,
one of the frozen embryos could be thawed and implanted into the uterine
wall for development of another identical child. The bone marrow from
this child could then be used to help save the life of the child,
perhaps even without the necessity of carrying the child to full term:
(Cloning 1117). This again raises the question of what moral status a
fetus should have, if any at all?
FEDERAL GUIDELINES FOR HUMAN EMBRYO
Because human embryo research is
just in its infancy, there has been a rush to decide what guidelines are
going to be instituted for governing cloning experiments. To assist the
National Institutes of Health (NIH) in determining which cloning
experiments to fund, a medical panel was set up to form a preliminary
set of guidelines. Steven Muller, the head of the panel, set out with
the help of several prominent biologists including, Brigid Hogan and
embryology specialist Mark Hughes, to put together a set of guidelines
that would satisfy the concerns of both the scientific and religious
communities. The religious community vigorously opposes all human
cloning procedures. The scientific community sympathizes with the
religious communities concerns, but does not want to lose the enormous
amount of information that may be gained by human embryo cloning.
Muller's panel announced a set of guidelines that they hope would be
acceptable to both communities. They recommended research be permitted
on preexisting embryos. These embryos would be allowed to develop up to
and including the fourteenth day. Researchers would also be allowed to
produce new embryos only for what the NIH considers "compelling
research." Researchers would also be permitted to remove some of
the embryonic cells from embryos that are destined for in vitro
fertilization at a later time: (Marshall 1024). The panel did not come
to a decision in several other areas of research funding. Research on
fetal oocytes and research on embryos whose donator is unavailable to
give consent were left undecided. This brings up a question as to
whether or not a person who aborts a fetus still has parental rights
pertaining to that fetus. Legally the aborted fetus is not a person and
has no legal status. Society needs to decide whether or not the fetus
has a moral status. The panel suggested that research might be permitted
after the fourteenth day of development depending on the circumstances,
but definitely not after the eighteenth day, when neural tube closure
begins. The neural tube is the beginning of the nervous system,
including the brain, in adult humans: (Marshall 1024). Thus the
scientific community seems to be giving more moral consideration to an
embryo then a majority of society gives to a more developed fetus. The
experiments that the panel recommended be banned include impregnating
human embryos in other animal species, impregnating cloned embryos into
humans, the use of embryos for sex selection, or the transfer of one
nucleus from one embryo to another. These are but a few of the
procedures that the panel felt were inappropriate for federal funding:
(Marshall 1024). I want to be clear on this fact: the above limitations
only apply to federally funded experiments. Currently there are no laws
directly prohibiting any of the above procedures in private research
settings. It should also be stated that all of the above procedures have
or can be carried out with current technology.
Lets Wrap it Up!
Human embryo cloning obviously is
a great source for human advancement, and will more than likely help
millions of people world wide, but we must never overlook the possible
harm that it could cause as well. The United States will probably never
allow many of the more radical uses of human embryo clones, especially
for screening superficial traits, but there are countries in the world
that might not think twice about the ethical concerns. Ethnic cleansing
is occurring in many places around the world today, and embryo screening
and cloning maybe just another tool in their arsenal. Robert Stillman
probably did the best thing any scientist could ever do by shocking the
world to what lies ahead. As with any scientific or technological
advance the most important question that needs to be asked, is whether
or not the gains out weigh the potential losses?
April 7, 2000
A couple that
had been married for only two years was in a terrible car accident.
The wife walked away with a few cuts and bruises. The
husband, however was unconscious when the paramedics arrived. He
went into a coma shortly after arriving at the nearby hospital. He came
out of the coma but was never to be the same again. It turns out
that when he was in the accident he had severe head trauma, and would be
a vegetable the rest of his life. He could not take part in the
reproduction of children. The wife is now distraught because they
will never have children together. She heard about the possibility
of cloning and believes that it is the only way that she will ever have
children. Is it so?
The ethics of human cloning has become a great
issue in the past few years. The advocates for both sides of the
issue have many reasons to clone or not to clone. This is an
attempt to explore the pros and cons of human cloning and to provide
enough information of both sides of the arguments in order for the
reader to make their own informed decision on whether human cloning is
ethical or not. Cloning will first be defined. Then a brief
explanation of why questions concerning cloning humans have arisen will
be presented. Some things cannot be known for sure unless it is
tested, i.e., human cloning is allowed. Followed by that, a discussion
of the facts and opinions that support cloning will be presented and
then the same against cloning. Please remember that not all of
this has proven true nor is able to be proven yet, but has simply been
argued as a scientific hypothesis. Finally, my own personal
opinion will be stated.
Defining Human Cloning
When speaking of human cloning, what is meant?
Different groups and organizations define it differently. To
use a specific definition, the American Medical Association (AMA)
defined cloning as the production of genetically identical organisms
via somatic cell nuclear transfer. Somatic cell nuclear
transfer refers to the process which the nucleus of a somatic cell of
an existing organism is transferred into an oocyte from which the
nucleus has been removed (Council on Ethical and Judicial Affairs 1).
In other words, cloning is the method of produce a baby that has
the same genes as its parent. You take an egg and remove its
nucleus, which contains the DNA/genes. Then you take the DNA from
an adult cell and insert it into the egg, either by fusing the adult
cell with the enucleated egg, or by a sophisticated nuclear transfer.
You then stimulate the reconstructed egg electrically or
chemically and try to make it start to divide and become an embryo.
You then use the same process to implant the egg into a surrogate
mother that you would use with artificial insemination. (Eibert)
However, many groups have used a broader
definition of cloning. They include the production of tissues and
organs through growing cells or tissues in cultures along with the
actual producing of embryos to be born. This is done with the use
of stem cells. When an egg is fertilized and begins to divide, the
cells are all alike. As the cells divide, certain cells
differentiate and become the stem cells that produce certain tissue and
then organs. Research in this very active. There is still
much for scientists to learn about cell differentiation and how it
works. To a clone an organ, a stem cell must be produced and then
used to a clone that specific organ. For the sake of this paper,
both definitions will be used in order to cover all opinions.
One must understand that cloning does not produce
an exact copy of the person being cloned. What cloning does, is
that it copies the DNA/genes of the person and creates a duplicate
genetically. The person will not be a Xerox copy. He or she
will grow up in a different environment than the clone, with different
experiences and different opportunities. Genetics does not wholly
define a person and the personality.
How It All Started
In February 1997, when embryologist Ian Wilmut and
his colleagues at Roslin Institute in Scotland were able to clone a
lamb, named Dolly, the world was introduced to a new possibility and
will never be the same again (Nash). Before this, cloning was
thought to be impossible, but now there is living proof that the
technology and knowledge to clone animals exist. Questions began
to arise within governments and scientific organizations and they began
to respond. Are humans next? Is it possible to use this
procedure to clone humans also? Would anyone actually try?
What can we learn if we clone humans? How will this affect
the world? These are only a few of the questions that have
surfaced and need answered. A whole new concept in ethics was
created when the birth of Dolly was announced.
There are a great number of possible medical
benefits and disadvantages to cloning and its technology. They include
Potential Medical Benefits
possibility that through cloning technology we will learn to renew
activity of damaged cells by growing new cells and replacing them.
capability to create humans with identical genetic makeup to act as
organ donors for each other, i.e., kidney and bone marrow transplants.
benefit of studying cell differentiation at the same time that cloning
is studied and developed.
couples will be able to have offspring will have either the mothers
or fathers genetic pattern.
Potential Harms and Disadvantages
possibility of compromising individualities.
of genetic variation.
black market of fetuses may arise from desirable donors that will
want to be able to clone themselves, i.e., movie stars, athletes, and
is not well developed. It has a low fertility rate. In
cloning Dolly, 277 eggs were used, 30 started to divide, nine induced
pregnancy, and only one survived to term (Nash).
may be treated as second-class citizens.
psychosocial harms with impacts on the family and society.
The Governments Make a Move
The governments went to work shortly after the
cloning of Dolly. They wanted to take control and make laws before
anything drastic could ever happen. Several ethics committees were
asked to decide whether scientists should be allowed to try to clone
humans. Many of the committees found the data displayed above.
In the United States, the National Bioethics Advisory Commission
recommended a five-year moratorium on cloning a child through somatic
cell nuclear transfer (Council on Ethical and Judicial Affairs 1).
In the state of Michigan, Governor Engler signed a law last year
making human cloning illegal with harsh penalties if it is attempted
(Governor Engler...). In the United Kingdom, the Human
Fertilisation and Embryology Authority (HFEA) and the Human Genetics
Advisory Commission (HGEC) have approved human cloning for therapeutic
purposes, but not to clone children (HFEA supports Human Cloning in
U.K.). Many organizations have come out and stated their
opinions also. Amongst all this ethical defining, many people are
being ignored by the governments. People are speaking out about
what they want done.
Let Us Clone
After a couple has had their first child, to their
disappointment they become infertile and cannot have more children.
Cloning would enable such a couple to have a second child, perhaps
a younger twin to the child they already have. This example has a
very good argument. Many couples have difficulties having
children, and sometimes it is impossible for couples to have children
because they are infertile. Cloning would allow these couples to
have children. Also, occasionally a woman is born without a uterus
or has other complications and cannot produce eggs, then with the help
of a surrogate mother, she can have a child of her own using her own DNA
or her husbands.
This and the example at the beginning are both
arguments that some have made in promoting cloning. It is hard to
tell someone that they cannot use cloning to have children when no other
possible ways to produce offspring are available. This is one
reason why it is difficult to decide if cloning is ethical or not.
The following are some of the reasons why cloning should be
As just discussed, cloning can be used to help
benefit those that are sterile and cannot have children through the
normal, natural way. It is the desire of most couples to have
children and when it is impossible to bare children of your own, some
are willing to do anything to have a child. Cloning will allow
them to have a child or many children that have the genetic pattern of
one of the parents.
Through cloning, research can progress. It
is hard to say what we can learn from cloning if cloning is not allowed.
We possibly can learn more about cell differentiation. We
can learn enough to produce human organs without having to produce human
beings. We may develop technology to allow easier genetic testing
and fixing problems such as spinal cord injuries, cancer, Tay-Sachs
disease, and many more.
Cloning organs for organ transplants is one of the
major practical reasons that cloning should be allowed. There is
always a high demand for organs. Some argue for the cloning of
humans to create spare body parts. Others talk of just wanting to
clone an organ to replace a defective organ.
Rejuvenation is also a key argument for advocates
of cloning. Human cloning may one day reverse heart attacks.
Some scientists believe that by injecting cloned healthy heart
cells into damaged heart tissue will lead to healing of the heart (Human
Cloning Foundation). By combining the technology for cloning and
the technology for growing human stem cells, conditions like Alzheimer=s
disease, Parkinson=s disease, and degenerative joint disease may be
curable. The possibilities are endless and may be left
undiscovered if human cloning is banned.
Thou Shalt Not Clone
One of the main goals of the government is to
protect human life. Some people want the government to regulate
cloning and not allow it. Michigan=s government believes this and
became the first government to place a ban on cloning. As
mentioned before, the governor signed laws that prohibit engaging or
attempting to engage in human cloning. A Michigan state senator,
Mr. Bennett said, This legislation boils down to one thing:
Prohibiting the creation of human life for scientific research. Human
cloning is wrong; it will be five years from now; and wrong 100 years
from now! (Governor Engler...) Producing clones for
research or to use their parts is unethical. It would be against
the code of ethics of a doctor to harm a clone (i.e., use it for an
organ transplant). The clone would be a human being and deserve
all the rights and privileges that a non-cloned human has. A clone
should not be a second-class citizen. It is speculated that they
would be considered as such.
The American Medical Association holds four points
of reason why cloning should not take place. They are: 1) there
are unknown physical harms introduced by cloning, 2) unknown
psychosocial harms introduced by cloning, including violations of
autonomy and privacy, 3) impacts on familial and societal relations, and
4) potential effects on the human gene pool (Council on Ethical and
Judicial Affairs 4-6). We just simply do not know the harms that
will come from cloning.
Cloning would lead to the loss of individuality
because one=s genetic predispositions and conditions would be known.
If raised by a clone-parent or as a sibling to the cloned, one may
have great expectations to live up to. However, the human clones
could differ greatly in personality and even grow up with different
conditions than the cloned. Even monozygotic twins differ. This
could be a great stress to the clone and possibly even the loss of
ability to chose for itself (Council on Ethical and Judicial Affairs 5).
The long term genetic effects of cloning may cause
more problems than can be imagined. The question of what can go
wrong in cloning needs to be discussed. In an evolutionary
standpoint, cloning is not good. Evolution relies on a continual
mixing and matching of genes to keep the gene pool alive (McCormack).
With cloning, the natural process of selection of genes would be
bypassed and evolution would be impaired. The Council of
Ethical and Judicial Affairs for the AMA stated the following concerning
possible problems with mutations and clones:
the somatic cell from which clones originate likely will have acquired
mutations, serial cloning would compound the accumulation that occurs in
somatic cells. Although these mutations might not be apparent at
the time of cloning, genetics problems could become exacerbated in
future generations. (Council on Ethical and Judicial Affairs 6)
We can see that cloning can possibly change the
gene pool from how we now know it. Most likely, it would not be a
Technology as we presently know it will not
effectively support the cloning of humans. As mentioned before,
the success rate was quite low when cloning Dolly. Only one of the
277 tries succeeded, see chart 1. The same problems of the
difficulty of having the fertilized egg implant parallels with that in in
vitro fertilization. Technology has not yet been able to
provide an answer to this problem.
The fear that clones will be treated as
second-class citizens is also present. If a clone is created
to act as bone marrow or kidney donor, the question arises if they would
be treated like the first child? Would the parents even love this
child the same? If not, this would lead to negative self-esteem and/or
other physiological problems.
There is also the fear that some would want to
clone people to create large armies of the same soldier or even produce
large amounts of workers. This would also lead to the creation of
a second and lower class for clones.
From a Latter-day Saint point of view, the
Proclamation on the Family clearly does not agree with cloning. The
Proclamation states: We . . . declare that God has commanded that the
sacred powers of procreation are to be employed only between
man and woman, lawfully wedded as husband and wife. We declare
the means by which mortal life is created to be divinely
appointed. We affirm the sanctity of life and of its importance in
Gods plan. (Italics added) In other words, the power
to create humans is only to be used in a marriage between husband and
wife. Cloning only involves one parent, therefore it is not
following Gods plan in which a mans sperm and a womans egg are
needed to create life.
My Personal Recommendation
As a student studying biology, I have tried to
approach both sides and approach them with an unbiased opinion. I
personally think that the world of genetics is fascinating, but after
learning of what is now possible through technology, I changed my mind
about pursuing a career in the field. I see cloning as a wonderful
advancement in technology and knowledge. I do not think it should
be used to reproduce humans though. I do not believe that we
should try to develop other ways beside the natural way to bring life
into this world. I strongly believe that God created us and that
we are subjected to His laws and must obey. The laws of God that
have the worst punishment deal with bringing life into the world and
taking life out of the world. I believe that cloning people would
fall under these laws also.
Cloning tissues and organs falls under a different
category that cloning human beings. I think it would be
advantageous to science and medicine to clone tissues and organs. However,
the research in this involves fetal tissue which is a completely
different ethical discussion. I do not know enough about the
procedure be against it. So, with my present understanding I would
allow cloning for tissues and organs.
Cloning can revolutionize the world and the way we
live or it may be so minimal that it would not affect us at all if it is
allowed. The first human to be cloned was reported in Korea by Dr.
Kim Seung Bo and Dr. Lee Bo-Yeon. The clone was born and then
killed just days into life (Alton). Before we knew it, the first
clone was created and then destroyed. Is this the world you want
to live in? Each person individually must decide for himself or
herself if they believe that cloning should be allowed or if the
governments should intervene with it.
Ó 7 Apr 2000, Joseph Farnsworth