a. Websites
www.newscientist.com/nsplus/insight/clone/clone.html
A special report from New Scientist
that's supposedly "everything you always wanted to know"
Includes introduction, article index, FAQ, web sightings, bioethics,
and news. Has links to New Scientist articles from March 1997-November
1999. The web sightings list some of the better sites on cloning
and a couple of scifi things.
www.phrma.org/genomics/cloning/
Includes: ° General Information
& News
° Ethical and Legal Issues
° Government Resources
° Research Institutions
° Advisory Committees & Studies
° Scientific Organizations
° Books on this topic
° Comments
° Stem Cell Research
° US State Cloning Legislation
www.humancloning.org/
The "official site" in support
of human cloning
afgen.com/cloning.html
Collection of articles on Bill Clinton's
stance on human cloning, cloned monkeys, legal
battles, and theological questions.
library.thinkquest.org/19037/clone_links.html
Thorough collection of links about
cloning and related ideas including the facts, the future, diagrams,
ethics, transgenics.
gaytoday.badpuppy.com/cloning.htm
Gay Today's series on cloning. Including
"Human Cloning: a Promising Cornucopia" and "Staying
youthful-Curing AIDS-Human Cloning" and "First Cloning
Rights Group Led by Gay Pioneer"
www.pathfinder.com/TIME/cloning/home.html
Time Magazine's special on cloning.
Excellent graphics, simply stated, but well covered.
www.sciam.com/1998/1298issue/1298wilmut.html
A Scientific American article by Ian
Wilmut. Also has other links and suggested further reading
www.ri.bbsrc.ac.uk/library/research/cloning/
The official site of the Roslin Institute.
www.teleport.com/~samc/clone/
Welcome to the clone age! A very thorough
site with lots of links. Including about the recent announcement
of a cloned monkey.
www.purefood.org/patlink.html
CLONING AND PATENTS, Xenotransplantation:
News, Articles and Links. Mostly newspaper articles about cloning
and genetic engineering.
dspace.dial.pipex.com/srtscot/cloning.shtml
The Church of Scotland's page on the
ethics of cloning. Covers both human and animal cloning. There
are also pages on gene therapy and genetic engineering and human
genetics and patents and environment, etc.
Back to top of page
b. Articles
Kluger, Jeffrey. (1999).
"Goodbye Dolly." Time. 153(22): 70.
Abstract: More than 2 years have passed since the announcement
of the successful cloning of a sheep known as Dolly. Scientists
have anxiously awaited signs of aging in Dolly to determine if
theories are correct that clones may grow old sooner due to the
age of the parent cells from which they were cloned. Recent reports
indicate that some clones may indeed age faster and, therefore,
may have a shorter life span than a normal newborn. This aging
appears to involve telomeres, bands at the ends of chromosomes.
Telomeres can be said to cap the chromosome strand like the plastic
sleeves at the ends of shoelaces. As animals age, the telomeres
become shorter. This shortening causes chromosomes to fray and
therganism itself to become frail. Researchers have studied the
telomeres of Dolly and other cloned sheep and have found that
the telomeres are shorter than those of normal sheep of the same
age. They reported that Dolly had the shortest telomeres of all.
Dolly had been cloned from a 6-year-old sheep, while the others
had been cloned from embryos. Age of the donor cell probably plays
a role in the shorter telomeres; however, researchers have discovered
that the time the clone spends in the test tube before transfer
to the womb can also affect the telomeres' length. Cells normally
go through 150 divisions in their lifetimes. Scientists note that
cells in test tube culture can go through as many as 20 divisions,
which is considered to be a significant percentage. The cloned
sheep are not expected to meet their demise because of frayed
telomeres, but rather from natural causes. However, if the much-longer-lived
humans are ever cloned, rapid aging could be a great concern.
Fischman, Josh. (1999). "How
to Build a Body Part." Time. 153: 54, 55.
Abstract: The discovery of stem cells, precursors to tissue and
organ development, and other advancements in cellular biology
have prompted 70 lawmakers to sign a letter petitioning the federal
government to ban research into the growing of extra body organs
for transplanting. By making use of ordinary cells, however, scientists
have circumvented the controversy over using aborted fetuses and
unwanted embryos for organ development. The technology of tissue
engineering has enabled scientists to help patients across the
U.S. A skin patch for healing sores and skin ulcers was the first
engineered organ approved by the the U.S. Food and Drug Administration.
Researchers have discovered how to use polymers to shape molds
into which cells can grow and take shape; at this point the molds
then dissolve. According to Francois Auger, an infectious-disease
specialist and maker of artificial blood vessels at Laval University
in Quebec City, Canada, cells will do the prescribed work if they
are treated properly. Proper treatment of bone cells by anethesiologist
Charles Vacanti, who is also director of the Center for Tissue
Engineering at the University of Massachusetts Medical Center
in Worcester, enables him to grow bone tissue inside the voids
of coral shaped to specifications. Other scientists have used
shaped forms of polymer to mold cell growth into the shapes of
fingers. Vacanti's brother Joseph has used polymer and sheep-muscle
to create blood vessels, which then are attached to a sheep's
pulmonary artery. The muscle cells are then exercised and gain
strength. Anthony Atala, a surgeon at Boston's Children's Hospital,
has used muscle cells from the outside of dog bladders and lining
cells to grow tissue to cover and line the sides of a polymer
sphere and successfully transplanted the artificial bladder into
a dog's urinary system. Although using the patient's cells overcomes
problems with rejection, the organ growth rates require as much
as several weeks. Michael Sefton, who runs the tissue-engineering
center at the University of Toronto, has conceived a ready-made
heart that could be grown with genetically engineered cells that
would block the signals that evoke immune responses of the host.
Healy, Bernadine. (1999). "Ian
Wilmut." Time. 153(12): 116.
Abstract: British embryologist Ian Wilmut set out to improve the
productivity of farm animals and in doing so, he successfully
cloned the sheep known as Dolly. Dolly was reproduced from a single
mammary cell from an adult ewe in 1997. This line of research
had been abandoned by other major scientific research centers.
Wilmut believes that any experimentation with humans should be
kept to the level of cells and proteins and believes it is ethically
unacceptable to use his technique to clone a human. It was, however,
this aspect of his work that attracted the public's attention.
Physicist and self-trained researcher Richard Sneed soon proclaimed
his intentions of cloning a human, and although few scientists
found him credible, this was frightening to many people. Potentially,
cloning could play a variety of roles in medicine: basic research,
new therapies, infertility solutions, even the cloning of a dying
loved one. What is not yet clear is whether clones will die young
because of their older DNA or whether they will suffer environmental
mutations acquired during the life of their adult parent. Dolly
and the strangeness of her background seem remote to many people
and irrelevant to everyday life, but cloning shakes ethical foundations,
social norms, and religious beliefs. It raises questions such
as what the role of clones in society may be; whether clones are
an asexual variant on incest; whether they could become human
slaves or organ donors; who their parents are; who their family
is, and whether they are made in God's image or man's. It is difficult
to discuss cloning in a world where there are widely diverging
ethical values and where it often seems that anything is permitted.
Israel, Australia, China and most European countries have already
prohibited cloning, but the U.S. has not. The question remains
whether cloning will sneak up on society so that one day a human
infant may be produced in secret. Ian Wilmut, the father of cloning,
is passionate about honoring the individuality of the child and
believes that human cloning should be banned.
Stone, Richard. (1999). "Cloning
the Woolly Mammoth." Discover. 20: 56-63.
Abstract: Japanese biologists are leading an attempt to find remnants
of a woolly mammoth that may be preserved well enough to supply
modern technology with viable sperm or oocytes that could be used
in a selective breeding program. Woolly mammoths were most successful
during the Pleistocene Epoch from 1.8 million years ago up to
the end of the last ice age about 11,000 years ago. The last ones
died out about 3,800 years ago. A few proteins and fragmented
genes have been preserved well enough in the Siberian permafrost
for scientists to recover and compare them with those of modern
elephants. Kazufumi Goto, at Kagoshima University in Japan, believes
that the resurrection of the mammoth merely requires well-preserved
tissue. Goto experimented with bull semen and cow eggs and found
that a sperm subjected to repeated freezing and thawing was essentially
dead but still able to promote cell cleavage in an egg. Goto began
a partnership with Akira Iritani, chairman of the department of
genetic engineering at Kinki University in Japan. The researchers
prepared for cloning DNA from a woolly mammoth, if suitable material
could be found. The researchers set out for Duvannyi Yar, a renowned
mammoth site in Russia that contains about 100 mammoth skeletons
per square kilometer. Despite a few unsuccessful attempts at uncovering
frozen sperm, the Japanese researchers plan to return in the summer
of 1999 to known sites of mammoth remnants. Kinki University is
also offering 1 million yen ($9,000) for mammoth tissue that is
preserved sufficiently for tissue-cloning experiments, according
to Iritani. A successful cloning experiment could mean that a
woolly mammoth would be added to Pleistocene Park, a 160-square-kilometer
preserve near Duvannyi Yar where 32 Yakutian horses, moose, reindeer,
and American bison were recently placed.
Cohen, Philip. (1999). "Grow-Your-Own
Organs: Adults May Have All the Cells Needed to Regenerate Their
Own Tissues." New Scientist. 161(2171) January 30,
1999,
Abstract: Using a patient's own tissue to grow replacement organs
could be easier than anyone imagined, judging by the ease with
which scientists have turned adult brain cells into blood. An
international team says that simply injecting the brain's neural
stem cells (NSCs) into the bone marrow of mice is enough to promote
this metamorphosis. If the same is true in humans, the technique
could lead to new sources of perfectly matched transplanted tissue--without
the controversial use of human embryonic stem (ES) cells, which
are taken from aborted fetuses or discarded in vitro fertilization
embryos. Until two years ago, the process of specialization, in
which ES cells change to form individual tissues, was considered
irreversible. The creators of the cloned sheep Dolly showed that
the development potential of an adult cell could be recovered.
Angelo Vescovi of the National Neurological Institute in Milan,
Italy, and his team suspected that some reprogramming might happen
without cellular surgery. Vescovi's team injected NSCs from adult
mice into the bone marrow of mice that had been irradiated to
cripple the cells that form blood, hoping that this new environment
might trigger reprogramming. After 5 months, the recipients developed
new blood cells. Genetic analysis confirmed that many of these
cells were direct descendants of the NSCs. Vescovi's latest results
suggest that the new blood cells are functional, since the irradiated
mice that received the NSC transplant lived longer than the irradiated
mice that received no transplanted cells. Vescovi believes that
it may be possible to use stem cells from other tissues such as
skin as the source of new tissue. These cells would be easier
to obtain than the brain stem cells used in his work so far.
Watts, Jonathan and Kelly Morris.
(1999)."Human Cloning Trial Met with Outrage and Scepticism."
The Lancet. 353(9146): 43.
Abstract: Researchers at a Korean university infertility clinic
announced recently that they had fused an adult cell with an enucleated
egg to create an embryo that divided twice to reach the four-cell
stage. The researchers then terminated the experiment to avoid
flouting ethical guidelines, but claim that the next step would
have been to transfer the embryo to a uterus. The researchers
used the Honolulu technique, in which a somatic-cell nucleus is
inserted into an enucleated egg, followed by ovification of the
egg. This technique is a modification of the one used to clone
Dolly the sheep, the first vertebrate cloned from an adult cell.
The Korean researchers' claims were challenged by scientists around
the world. Some noted that the unpublished work of the Korean
team is not part of a major cloning project. A Japanese researcher
who cloned twin calves said he did not believe the report. A scientist
at the Roslin Institute in Scotland where Dolly was cloned states
that taking a putative embryo to the four-cell stage is not that
important, because a human embryo is preprogrammed to divide to
at least the eight-cell stage. He explained that the 100,000 genes
in the somatic cell nucleus just be activated rapidly and perform
perfectly for 9 months to produce a live healthy clone. The low
success rate in animal cloning suggests that a cloned human embryo
would likely be stillborn or die after birth. He stressed that
nuclear transfer is not just a variation on in-vitro fertilization.
In somatic-cell cloning there is also the potential for inheritance
of somatic-cell mutations from the donor, since nuclear transfer
bypasses mechanisms that correct DNA errors in germ cells. There
is also a possibility that DNA in a cloned animal may behave like
that of an animal with the combined ages of donor and offspring,
possibly shortening the clone's life. The concerns expressed by
scientists add to the serious ethical reservations expressed around
the world. In Korea, protesters demonstrated outside the university
where the cloning experiments took place. Korean newspapers expressed
a mixture of dismay and pride. There was a general agreement that
Korea needs laws to curb cloning research.
Wilmut, Ian. (1998). "Cloning
for Medicine." Scientific American. 279: 58-63.
Abstract: Innovations in cloning techniques have opened up a world
of possibilities for biomedical researchers. It may soon be possible
to clone genetically altered animals as organ donors for humans,
so that they will not initiate rejection in the recipient. Animals
may also be bred to produce cells used for replacing damaged human
cells in such diseases as Parkinson's, diabetes, and muscular
dystrophy. Universal stem cells, or cells that are in very early
states of development and may be genetically influenced to develop
into certain tissues, could be another outcome of cloning technology.
Although ethical questions would be raised, it may also be possible
to raise animals affected with human diseases such as cystic fibrosis
for research purposes. Herds of cattle may be cloned that will
not be susceptible to bovine spongiform encephalitis, or mad cow
disease. Early cloning techniques required scientists to genetically
copy cells isolated from early-stage embryos. This process was
tedious and impractical for widespread use. In 1995 lambs born
at the Roslin Institute in Scotland were the successful offspring
of a process that introduced genetic material into cultured embryo
cells. Because cultured cells are relatively easy to work with,
this technique was a breakthrough in practical cloning. The birth
of the sheep Dolly in 1997 was another milestone in cloning techniques,
because the cultured cells were taken from a mature ewe rather
than an embryo. The process of transferring genetic material to
cultured cells is repeatable, but limited in success; only 1-2%
of such embryos survive. Transgenic, or genetically modified,
animals are produced by injecting a constructed DNA sequence with
a desired trait into fertilized eggs. Instead of injecting DNA
into an egg, it has been discovered that eggs can be chemically
induced to take up a DNA construct, making the process more practical
and efficient. Polly, a transgenic sheep born in 1997, carries
the gene for human factor IX, a blood-clotting protein, which
is expressed in her milk. Transgenic animals have the potential
to produce substances that may control or cure many human diseases.
Cohen, Philip. (1998/1999). "Cloning
by Numbers." New Scientist. 160(2165/6/7): 28-29
Abstract: The second group to clone an adult animal was a team
led by Ryuzo Yanagimachi at the University of Hawaii, Honolulu.
Yanagimachi's team produced a clone named Cumulina on October
3, 1997. Since then the group has produced some 80 cloned mice,
giving further credence to the work by the Scottish team that
produced the first adult animal clone, a sheep named Dolly. Media
groups did not predict that Yanagimachi's lab would be the next
to produce a clone because the lab initially focused on mouse
vitro fertilization, not cloning. Cloning a mouse is extremely
difficult, given the small window of opportunity for gene reprogramming.
A post-doctorate student named Teruhito Wakayama explored mice
cloning as a personal project. Wakayama used cumulus cells, cells
present on the egg surface, as donor cells. He removed the cell
nucleus and injected the nucleus into an egg cell with its own
genetic material removed to produce a living embryo. When Yanagimachi
saw this initial success, the entire lab collaborated to produce
a cloned mouse a couples of month later. It turns out both the
novel technique of injecting a nucleus into an egg and the choice
of cumulus cells, of which only some 2% produce clones, were what
was needed for successful mice cloning. Since mice reproduce rapidly,
the clones are useful tools in discovering more about the aging
process in clones, the reasons for cloning success or failure,
and the revitalization of dormant genes. This second attempt at
adult animal cloning has been followed by the cloning of adult
cows by a group in Japan and by a group in New Zealand.
Gearhart, John. (1998). "New
Potential for Human Embryonic Stem Cells." Science.
282(5391): 1061-1063.
Abstract: Stem cells give rise to all of the different tissue
types found in animals. Because these cells, which are present
in the early stages of embryo development, are self-renewing,
a cultured source of human stem cells able to differentiate into
a variety of tissue types would be invaluable in basic medical
research and in transplantation therapies. Now researchers at
the University of Wisconsin at Madison and the Rambam Medical
Center in Haifa, Israel, have succeeded in growing human embryonic
stem (ES) cells in culture. These cells were derived from two
embryonic tissues: inner cell masses of blastocysts and primordial
germ cells. The ES cell lines were continuously cultured over
a 5-6 month period and expressed the high levels of telomerase
activity typical of cells with a high replicative lifespan. Four
cell lines tested produced termatomas (a type of tumor) when grown
in immunocompromised mice. In these tumors, researchers detected
differentiated cells derived from all three embryonic germ layers:
ectoderm; mesoderm; and definitive endoderm. The potential use
of human ES cells is far-reaching. ES cells could prove important
to in vitro studies of normal human embryogenesis, abnormal development,
human gene searches, drug and teratogen testing, and as a renewable
source of cells for tissue transplantation, and cell, replacement,
and gene therapies. Likely targets for tissue transplantation
therapy include neurodegenerative disorders, diabetes, spinal
cord injury, and hematopoietic repopulation. However, because
human embryos are involved in stem cell research, advances in
this area are likely to spark public debate--a debate likely to
center around the source of the cells, the potential for human
cloning, and concerns about germ line modification.
Kaye, Howard L. (1998). "Anxiety
and Genetic Manipulation: A Sociological View."
Perspectives in Biology and Medicine. 41: 483-490.
Abstract: While the announcement of the successful cloning of
a sheep caused widespread panic and distrust, little has been
done to understand and respect the nature of these fears. The
public concern has been treated as an emotional response based
in ignorance and superstition. Some scientists say that cloning
offers no greater threat to human autonomy than does twinning,
and no greater threat to the family than does artificial insemination
with donor semen, in vitro fertilization, or surrogacy, and that
identical genes do not make identical people. Those espousing
this view believe that alleviating public anxieties requires better
science education, not a permanent ban on cloning. The National
Bioethics Association agrees, saying that much of the public's
fear is rooted in science fiction and gross misunderstandings
of human biology and psychology. Many scientists think that the
public's moral intuitions are not solid enough to impede scientific
progress and that they will embrace the technology when the first
successful human clonings are achieved. Sociologists disagree.
They say that the almost universal fear that cloning is a threat
to the dignity and sanctity of human life should not be dismissed
lightly. When it comes to taking a moral stand on unresolved issues,
sociology can play a vital role. It can best serve moral life
by helping people see clearly the ultimate meaning of their actions.
It can help the public anticipate the means that might be necessary
to achieve a particular end. It can confront them with consequences
that they might otherwise not foresee by helping them understand
the social and cultural contexts in which particular courses of
action would be followed. Sociology can show the necessity of
choice from among desirable ends and compel people to reexamine
philosophical arguments and utopian aspirations in the light of
lived human experience carefully observed in all its dimensions.
In these ways it can help people make moral judgments on subjects
such as ethics, transplantation, and cloning.
Pennisi, Elizabeth. (1998). "Cloned
Mice Provide Company for Dolly."Science. 281(5376):
495-496.
Abstract: Researchers at John A. Burns School of Medicine at the
University of Hawaii in Honolulu have succeeded in replicating
the cloning of an animal from adult cells-- the same process that
produced the cloned sheep "Dolly" and made international
headlines in 1997. The Hawaii research team reports the cloning
of 50 mice so far. Other researchers who have analyzed Dolly's
DNA have confirmed that she is indeed a clone of the ewe whose
cellular material was used in the experiment. In the Hawaiian
cloning experiment, researchers used the same basic technique
as the Scottish team that produced Dolly. Nuclei from adult cells
were transferred into eggs whose own nuclei had been removed.
But while the Scottish team triggered the fusing of the adult
cells with the eggs by applying an electrical pulse, the Hawaiian
team used a very fine needle to take up the donor cell nucleus
and inject it into an enucleated egg. The Hawaiian team also differed
from the Scottish team in the method used to trigger development
of the eggs. While Dolly's egg was jolted to development using
an electrical pulse, the Hawaiian team put the eggs into a culture
medium containing strontium, which stimulates the release of calcium
from the internal stores, triggering the development of the fertilized
eggs. This strategy proved most effective with cumulus cells,
which surround an egg as it matures. The resulting cloned mice
appear normal. The researchers have cloned some clones and mated
others; all progeny seem normal and healthy.
Lemonick, Michael D. (1998). "Dolly,
You're History." Time. 152: 64-65.
Abstract: Reproductive biologists have concluded, following over
a year's research, that the famous cloned sheep Dolly is indeed,
a bona fide clone. In her wake has come a veritable population
boom of cloned mice, making what recently seemed a miraculous
achievement now appear to be a routine procedure. The primary
difference between a cloned animal and one normally conceived
is that the clone is created from adult, differentiated cells,
while
normally conceived animals are derived initially from fetal, undifferentiated
cells.
A few years back, Japanese postdoctoral student Teruhiko Wakayama,
who had studied cloning as a hobby at the University of Hawaii,
began to work seriously on attempting to clone mice during his
spare time. Although mice had long been considered all but impossible
to clone because of the nature of their egg cells and the rapid
development of their embryos, Wakayama overcame these problems.
Just a few months after Dolly was born, Wakayama succeeded in
cloning the cumulus cells that envelope the egg in the ovary.
Unlike Wilmut, Wakayama did not use electric shocks to trigger
the merging of a host egg with a donor cell. Instead, he injected
just the adult nucleus into a nucleus-free host and let the hybrid
cell "rest" for several hours before stimulating its
division. An astonishing 3% of Wakayama's clones survived, all
of them normal in every way. Their DNA proved so robust that they
themselves could be cloned and their clones cloned. Wakayama's
success has taken the possibility of the routine cloning of larger
animals--including humans--a step closer to reality. While scientists
point out the potential advantages, such as the mass production
of research animals bioengineered to provide human-compatible
transplant organs, ethicists point out that there are many problems
inherent in human cloning.
Cohen, Philip. (1998)."Clone
Alone." New Scientist. 158(2133): 32-35.
Abstract: Soon after Ian Wilmut announced in 1997 that he had
produced a clone of a sheep, whom he named Dolly, some skeptics
were not convinced. The research Wilmut and his group conducted
at the Roslin Institute in Scotland is an amazing discovery, given
the recent unsuccessful history of cloning adult animals. John
Gurdon first attempted cloning frogs in the 1960s and 1970s. He
had success with tadpole cells, but failed whenever he tried to
use an adult frog cell as the donor cell. Cloning seemed to work
as long as cells were not specialized, as is the case with an
adult cell. Then Dolly came along. Researchers did not expect
success so they were not concerned that their donor was dead with
no trace of extra donor tissue. The cloning of an adult animal
has not been repeated. This is one among many criticisms of the
work of Wilmut. Some feel that the udder cells used to produce
Dolly were not tested against adult cells. Norton Zinder and Vittorio
Sgaramella wrote of their criticism of the Dolly experiment. First,
they say that because Wilmut and his group never compared Dolly's
genes with the original adult sheep's, they cannot say for certain
that Dolly is a clone. Dolly has been shown only to be related
to the culture line of cells that the donor genes originated from.
Furthermore, Wilmut's group compared only four regions of DNA
to prove their connection between Dolly and the original cultured
sheep cells. Zinder and Sgaramella also warn that since the original
adult donating Dolly's genes was pregnant, it could mean that
Dolly's cells originated from fetal cells. To counter their critics,
Wilmut and his group will conduct more advanced analyses of Dolly.
First, independent laboratories will carry out a more extensive
analysis of Dolly's DNA with udder tissue to determine the probability
of a random match. Second, collaborators have found no evidence
that fetal cells are present in the blood of pregnant ewes. Third,
an independent lab will measure the length of chromosome ends,
which will give an indication if Dolly has chromosomes similar
to a 6-year-old sheep. The goal of Wilmut's team is to prove that
Dolly is indeed an adult clone until they are able to repeat the
Dolly experiment.
Nash, J. Madeleine. (1998). "The
Case for Cloning." Time. 151: 81.
Abstract: The benefits and risks associated with human cloning
should be thoroughly evaluated before prohibitive legislation
is enacted. However, fears that access to cloning will be easy
and widespread have caused many legislators to hastily pass general
bans against human cloning. In fact, the Clinton administration
supports a proposal with a 5-year moratorium. In addition, House
majority leader Dick Armey is backing a bill for permanently banning
human cloning, while at least 18 states are considering regulations
of their own. The reality that no legislation is sometimes better
than bad legislation should temper this debate. California's poorly
written legislation temporarily bans human cloning, as well as
a promising new infertility treatment. Cloning can have important
medical implications. Biologists can parlay the technique used
to produce Dolly the sheep solely for medical purposes. Biologists
can extract healthy cells from a patient and create embryonic
clones. The infusion of growth factors will ensure that the clone
does not develop into a fetus, but into specialized cells and
tissue for treatment purposes. For instance, cloned cells could
provide a graft of new skin for a burn patient and a bone marrow
infusion for a leukemia patient. The rejection danger is eliminated,
as well as the need for immunosuppressive drugs. The dangers that
exist in cloning advances are not in their identical clones that
many fear will be churned out, but in the application for genetic
engineering to humans. Initially, parents will want genetic diseases
such as Tay-Sachs to be eliminated. Then they may want familial
predispositions to be eliminated. The ultimate danger will be
the desire to enhance normal genetic traits. The issues to be
dealt with are which risks and which potential benefits may be
withheld from our society due to panic driven decisions.
Morell, Virginia. (1998). "A
Clone of One's Own." Discover. 19: 82-89.
Abstract: The birth of the now-renowned sheep Dolly, cloned from
an adult cell, has opened up a maelstrom of public controversy
and generated endless speculation by scientists, philosophers,
doctors, and politicians. It has led to a media circus centered
around eccentrics such as a Chicago physicist-turned-biologist
Richard Seed, who wants to start his own human cloning business,
and French chemist Brigitte Boisselier, who claims aliens had
told her all about cloning years ago. On the purely practical
side, cloning may eventually offer a way to provide an infertile
or homosexual couple with a means to produce a biological child.
Researchers say that although such a child may closely resemble
their parent in many ways, the experiential differences from the
womb on will ensure that such a child is completely
unique. However, as most researchers are quick to point out, being
able to safely clone humans--if indeed it ever becomes a viable
possibility--is still a long way off. Some geneticists think that
damage from aging DNA may be passed on to a cloned infant, and
long-term studies of cloned mammals will be the only way to determine
if this is so. Researcher Don Wolf of the Oregon Regional Primate
Research Center has been working to clone rhesus monkeys as a
way to create a supply of genetically controlled animals for medical
research. Wolf observes that the cloning process is highly involved
and far from certain in its results. When Dolly was created, for
example, the adult cells from a sheep's udder were placed in a
growth serum and "starved" for 5 days to render them
inactive. These cells were then fused with 277 different eggs.
Of these 277 efforts, 276 failed. Only one--which became Dolly--was
successful. Researchers still do not know which cell from the
udder worked or why, nor if the serum starvation method will work
on other species. Many scientists consider that it would be highly
unethical at this stage to try cloning in humans. Nonetheless,
cloning is likely being perfected by someone somewhere. And once
that happens, it is only a matter of time before the first human
clones appear.
Wills, Christopher. (1998). "A
Sheep in Clone's Clothing?" Discover. 18: 22-23.
Abstract: Since February 1997 when Dolly, the world's first successful
clone of an adult mammal (a Dorset sheep), took the world by storm,
debates over both the practicality and ethics of cloning have
been ongoing. Previous attempts at cloning from adult animal cells
failed because the cells were too metabolically active, in the
wrong stage of the cell cycle, or had the wrong set of genes turned
on. Ian Wilmut of Edinburg's Roslin Institute, who cloned Dolly,
compensated for these problems by starving the cells he used for
several days before fusing them with enucleated eggs. This caused
the cells' DNA-copying machinery to cease, by stopping the cell
cycle and forcing cells into a suspended metabolic state similar
to that of an unfertilized egg. Nonetheless, Dolly was Wilmut's
only success in 277 tries.
Since then, ABS Global of Wisconsin
has developed a technique that can create cow embryos from the
skin, bladder, and udder cells of adult cows. Once these cells
were fused with enucleated eggs, and the fused cells had begun
to divide, a single cell was extracted and inserted into another
enucleated egg. When an embryo began to form, it was implanted
in a surrogate mother cow. ABS claims that as of this fall, the
pregnancies appeared to be progressing normally. So what happened
to Dolly? Researchers are watching the celebrity sheep to see
what long-term physiological effects her unusual conception may
have on her. Because she began life with a nucleus from an adult
cell, it is possible she may prematurely age. On the other hand,
the milieu of the egg cell may somehow be able to reverse the
genetic damage due to aging--an exciting prospect. Meanwhile,
Britain has already banned human cloning, and the U.S. is following
suit. In June 1997, President Clinton said he feared cloning could
lead to misguided and malevolent attempts to select certain traits,
even to
create certain kinds of children, making our children objects
rather than cherished individuals. One of the main fears of opponents
is that cloning represents total loss of individuality. Researchers
argue that even identical twins are not really identical, because
there is far more to development than genetics. A clone and its
parent would not develop in the same mother, nor in the same uterus
or egg. Although they will share nuclear DNA, clones will actually
have less in common developmentally than twins. Researchers say
that at present, the strongest argument against cloning is its
likelihood of failure. In previous work with cells from embryos,
three out of five lambs died soon after birth and showed developmental
abnormalities. Similar consequences with humans would be totally
unacceptable.
Pennisi, Elizabeth. (1997). "The
Lamb That Roared." Discover. 278(5346): 2038-2039.
Abstract: In February 1997, a 7-month-old lamb named Dolly was
the first animal cloned from an adult cell. Although animals had
been cloned before, creating a sheep from a single cell of a 6-year-old
ewe was a major technological feat that many had thought impossible.
Dolly's creation began when a team of researchers at the Roslin
Institute outside Edinburgh, Scotland, suspected that previous
failures in cloning were caused by donor DNA that was in a different
stage of cell cycle than the recipient egg cell. The researchers
used nuclear transfer to clone sheep from embryonic cells, and
in 1996 announced the birth of two cloned lambs. Next, they cloned
sheep from fetal fibroblast cells. And in partnership with a local
biotechnology company, they attempted what everyone had said was
impossible: to clone a sheep from adult cells. To do this, the
team used cultured udder cells, taken from a 6-year-old ewe, and
then starved them, forcing most of their genes to enter an inactive
phase that the researchers hoped would match the cell-cycle stage
of the recipient eggs. Once the udder-cell nuclei were transferred
into the eggs, still-unknown factors coaxed that inactivated 6-year-old
DNA to go back in time, so to speak, and apparently become totipotent
once
more, directing the eggs to develop into lambs. Out of 277 such
eggs, only one produced a healthy living animal: Dolly. No one,
not even the Roslin team, has made a second animal from an adult
cell. Attention is focused on the handful of labs worldwide working
on cloning in livestock. Most are starting with fetal say they
too have cloned either sheep or cows from fetal cells, whose DNA
can more easily be made totipotent. So far, several firms cells,
and one group has cloned monkeys from embryonic cells. Nuclear
transfer experiments are underway in other species too, ranging
from zebrafish to rabbits. Among basic researchers, the Scottish
group's success has inspired new experiments looking at how DNA
changes as a
cell matures.
Morton, Oliver. (1997). "First
Dolly, Now Headless Tadpoles." Science. 278(5339):
798.
Abstract: Eight months after it was announced that scientists
had successfully cloned an adult sheep by transferring one of
its cell nuclei to an egg, Britain's best-selling broadsheet newspaper,
the Sunday Times, ran a front-page headline about headless frogs.
The researcher who created the tadpoles while studying developmental
genes speculated about their practical use, stating that someday,
organs grown through nuclear transfer, followed by strict control
of developmental pathways, might provide compatible transplant
material for people who otherwise could not get organs. Debate
over the ethics of creating brainless humans for medical purposes
ensued. Ethicists were quoted as saying the whole idea was deplorable,
treating lives as means, and not ends. A developmental biologist
said that there are no interesting moral problems at all raised
by cloning organs: If the donor is never satient to begin with,
what could be the harm? The researcher working on frogs was investigating
the ability of homeobox genes to control development along the
long axis of the animal. He mentioned his work and its possible
long-term applications to a BBC documentary crew preparing a film
about Dolly and the age of cloning. Clones as sources of spare
parts are one of the constant components of the post-Dolly debate.
Whether the technologies that have stirred public fears will ever
become reality is difficult to say. PPL Therapeutics--the company
that has licensed the technique from the Roslin Institute where
Dolly was cloned, to produce transgenic animals--plans to engineer
and clone pigs as donors for xenotransplants (transplants between
species, e.g., animal to human). Cloning to produce just human
organs, not people, might be an alternative, but there is not
yet a real understanding of how this might be accomplished.
Wadman, Meredith. (1997). "U.S.
Biologists Adopt Cloning Moratorium." Nature. 389(6649):
319.
Abstract: The Federation of American Societies for Experimental
Biology (FASEB), one of the leading U.S. professional associations
of biologists, announced in September 1997 a voluntary 5-year
moratorium on the cloning of human beings. FASEB, however, is
also seeking to keep open a window allowing research on human
embryos that might otherwise fall under a wider ban on cloning-
related research. The president of FASEB, which has 14 member
societies representing more than 52,000 scientists, said that
his association would regard cloning a human being as an "unethical
and reprehensible act." The FASEB moratorium defines cloning
human beings as the duplication of an existing or previously existing
human being by transferring the nucleus of a differentiated, somatic
cell into an enucleated human oocyte, and implanting the resulting
product for intrauterine gestation and subsequent birth. The text
accompanying the moratorium makes a point of contrasting cloning
intended for implantation and for in vitro research. In Washington,
a bill was amended in July 1997 by the House of Representatives
Science committee to ban federal funding for the use of cloning
for in vitro research in human embryos as well as for producing
human beings. FASEB officials deny that the moratorium is intended
to respond to the House Science Committee's vote to outlaw the
use of cloning technology for in vitro research on human embryos.
By permitting research on human cells in vitro, scientists would
be able to better understand how adult nuclei are reprogrammed
by cellular cytoplasm, possibly opening avenues to novel ways
of repairing and regenerating human tissues, according to the
FASEB.
Thompson, Dick. (1997). "To
Ban or Not to Ban?" Time. 149(24): 66.
Abstract: In response to President Clinton's request, the National
Bioethics Advisory Commission issued a report that recommends
making the cloning of a human being a criminal offense in the
U.S. Before Dolly had been cloned from the mammary cell of an
adult ewe, scientists thought that the DNA of a mature mammalian
cell was pre- determined to build skin, bones, or soft tissue,
but not an entire organism. Scientists are eager to study how
a differentiated cell was made to behave like an embryo. While
examining the mechanisms by which genes are activated or deactivated,
scientists might even find clues to the origins of cancer and
diseases such as muscular dystrophy and cystic fibrosis. Although
the use of federal funds for research on human embryos has been
prohibited, privately owned labs, including in vitro-fertilization
clinics, grew through the 1980s. Some of the National Bioethics
Advisory Commission members believe that rapid growth in private
research will also occur with human cloning. The commission's
report, "Cloning Human Beings," strongly
recommends continuation of the ban on federally funded human-embryo
research, but only requests that the private sector decide for
itself not to deploy such research. Future hearings on the matter
could beg the question of where to draw the line, much as the
pro-life movement has been asking the question of whether life
begins at conception. John Cavanough-O'Keefe of the American Life
League attacked the commission on grounds that it was leaning
toward allowing human-cloning research as long as cloned embryos
are not implanted in a womb. Cavanough-O'Keefe finds the decision
doubly wrong in creating human embryos and then predetermining
their destruction. The commission members recommended that the
cloning issue be re- evaluated periodically because of the possibility
that society may one day find cloning more acceptable.
"Clinton Seeks to Ban Human
Cloning but Not All Experiments." New York Times.
June 10, 1997: B10.
Abstract: President Clinton said that he wants to ban the cloning
of human beings but allow some cloning research while Americans
debate the moral implications. He stopped short of banning the
cloning of animals and certain human genes for important biomedical
research. The President's proposal is based on the bioethics panel's
conclusion that it is "morally unacceptable" to create
a child through transferring the nucleus of an adult tissue cell
and implanting it into a woman's body. Scottish scientists used
such a process to create the sheep named Dolly, the first mammal
cloned from an adult cell. Before Dolly was born healthy and normal,
the effort had failed 277 times. Some of the lambs were born with
severe and lethal birth defects. After learning of Dolly in March
1997, President Clinton banned federal spending on cloning research
until the ethical and moral issues could be sorted out while urging
the private sector to follow suit.
Pennisi, Elizabeth. (1997). "Transgenic
Lambs from Cloning Lab." Science. 277(5326):
631.
Abstract: Prior to the birth of the lamb named Dolly, cloned from
the cells of an adult, three other lambs were cloned from fetal
cells. The two institutions responsible for cloning the lambs,
the Roslin Institute of Edinburgh, Scotland, and the Scottish
Biotechnology company PPL Therapeutics, have combined the fetal-cell
procedure with genetic engineering, taking cloning a step further
with the possibility of producing domestic animals with designer
genomes. On July 4, 1997, the birth of five lambs cloned from
fetal cells was announced. Different from Dolly and her cohorts,
these animals carry extra genes that researchers introduced into
the cells before they were cloned. A human gene was among the
extra genes, although the biotechnology firm will not disclose
the identity of the gene. This achievement could aid efforts to
develop livestock for producing human proteins, such as blood-
clotting factors. Fetal skin cells called fibroblasts were introduced
to DNA that included both the human transplant gene and the undisclosed
gene marker. After eliminating cells that did not express the
marker gene, the researchers tested to see which of the remaining
cells also took up the human gene. Following the same cloning
strategy used to produce Dolly, they removed the nuclei from mature
egg cells and used a brief electrical pulse to fuse the enucleated
eggs with the engineered fibroblasts, which had been starved of
nutrients. The pulse also jump-started the developmental program,
with the genetic instructions now coming from the fetal-cell DNA.
The eggs were then placed in the ewes to develop. All five of
the new lambs carry the marker gene, and one has already proved
to have the human gene in her cells. The birth of that lamb shows
that the foreign DNA in the fibroblast genome did not disrupt
the genetic instructions that guide the lamb's development. The
technique should facilitate the development of animals with customized
genomes, including those that have had genes removed as well as
added. The procedure could help in improving prospects for xenotransplantation
by removing immunogenic proteins from pigs whose organs would
be used for replacing ailing human ones.
Praded, Joni. (1997). "Cloning:
The Missing Debate." Animals. 130: 21-23.
Abstract: Scottish embryologist Ian Wilmut and his fellow researchers
at the Roslin Institute were the first to clone a mammal from
adult cells. They extracted an egg from an ewe and replaced the
genes of that egg with deoxyribonucleic acid (DNA) from another
adult ewe's mammary gland. Contrary to prior scientific belief,
an embryo developed. Wilmut inserted the embryo into a third ewe
who gave birth 150 days later, in July 1996, to "Dolly,"
an exact replica of the adult whose mammary gland was tapped.
Dolly's creation was first made public in February 1997, causing
a public frenzy over the ethics of cloning humans. Soon after
came the news that the Oregon Regional Primate Center had produced
sibling rhesus monkeys from cloned embryos. In the midst of the
debates over human cloning, concerns about the animals involved
in or created by cloning experiments were hardly mentioned. Some
animal advocates have reservations about creating any genetically
altered animal--clone or not. Animals are being created with serious
threats to their own health and welfare. While many believe the
benefits of research outweigh the cost of animal suffering, a
recent CNN poll reported 66% of the U.S. population opposes cloning
animals. Some scientists argue that eventually cloning technologies
could limit the number of research animals needed.
However, the biotechnology revolution has given rise to two brand-new
industries that will undoubtedly consume great numbers of animals:
one looks to mass-produce animals that can generate pharmaceuticals;
the other, animals whose organs can be humanized for use as spare
parts. The resolution of this debate will hopefully come from
a careful, widespread analysis of the issues at hand, intelligent
regulation, and a greater sense of social responsibility among
scientists and industry.
Coghlan, Andy. (1997). "Cloning
Report Leaves Loophole." New Scientist. June 14, 1997,
154(2086)
Abstract: An ethics panel comprised of scientific experts appointed
by President Bill Clinton delivered its conclusions to the President
in June 1997, stating that human cloning should be banned in the
U.S., but laws to control the practice should be flexible enough
to allow a
rethink in the future. The panel recommendations would allow researchers
in the private sector to make cloned human embryos for experimental
work, provided they are eventually destroyed rather than being
implanted. The National Bioethics Advisory Commission was asked
to review the implications of cloning immediately after researchers
at the Roslin Institute near Edinburgh, Scotland, announced the
creation of Dolly, a lamb cloned from an udder cell from an adult
ewe. Clinton introduced a moratorium on government funding for
human cloning research, and asked the private sector to observe
its own moratorium. The moratoria should be maintained for now,
the commission suggests. Clinton launched a bill to ban the creation
of children by cloning. The commission was unable to agree whether
cloning should be outlawed on moral grounds, but did agree that
safety concerns justify a ban on human cloning for the time being.
One concern of commission members is that cancer-causing mutations
in donor cells from an adult human would be inherited. Cloned
children might also suffer from disruption to a phenomenon called
imprinting, in which genes are normally activated differently
depending on whether they come from the mother or the father.
Another worry is that the clones would grow old prematurely. Advances
in animal cloning should be reviewed every 3 to 5 years, according
to the panel, to take account of medical techniques that might
be used safely in humans. Cloning may bring medical advances such
as the cloning of specific body tissues to repair injuries. The
idea of the creation of human clones merely to serve as organ
banks was termed "repugnant" by the panel.
Marwick, Charles. (1997). "Put
Human Cloning on Hold, Say Bioethicists." Journal of the
American Medical Association. 278: 13-14.
Abstract: According to the National Bioethics Commission, human
cloning should be put on hold temporarily. President Clinton asked
the group in February 1997 to review the legal and ethical issues
surrounding the cloning. The president's request was a response
to the successful cloning in Scotland of Dolly the sheep. The
commission recommends the enactment of federal legislation to
prohibit anyone from attempting to create a child through somatic
cell nuclear transfer cloning. The report called the procedure
morally unacceptable at this time. However, the report continued,
any legislation should be temporary and subject to review within
a 3- to 5-year period, at which time the technological situations
should be reevaluated and the ethical and social issues reviewed.
Transferring the nucleus of a somatic cell into an egg and implanting
it is the technique used by Ian Wilmut and colleagues that resulted
in the sheep Dolly. However, commission members were concerned
that human cloning by any technique, not just the one used by
the Scottish researchers, was unacceptable. The commission concluded
that to create children in this manner is unethical at this time
because of the evidence that such techniques would be neither
effective nor safe. The report noted that it took 277 tries before
the Scottish researchers succeeded in creating Dolly. Even if
safety concerns are resolved, significant concerns remain about
the negative impact of the use of such a technology on both individuals
and society.
Kolata, Gina. "Iconoclastic
Genius of Cloning." New York Times. June 3, 1997:
B7, B12.
Abstract: Dr. Steen Malte Willadsen is a leader in the field of
embryology. He started out as a veterinarian in his native country,
Denmark, then was a research fellow in England. Recently he was
cloning cattle embryos in Texas and western Canada, and today
he is a freelance innovator in Florida. Fellow scientists describe
Willadsen as a "genius and iconoclast," while some even
rumor he was the first to clone an adult animal. Dr. Willadsen
denies those rumors, though he was the first to clone an animal
from embryo cells. He has even made chimeras animals half
sheep and half goat -- and even a sheep/cow combination. Human
eggs are the subject of Willadsen's current research where he
is again pushing the envelope. At Cambridge in 1973 Willadsen
immersed himself in work on farm animal embryology. In his perfection
of methods for freezing sheep and cow embryos, wild and daring
experiments were not out of the question for Willadsen. He split
embryos in two to create twins and later with Carole Fehily (who
later became his wife), he created chimeras by mixing cells from
embryos of different species. The chimeras were a minor part of
his research, with the main focus always animal breeding, a potentially
lucrative business. In 1986 Dr. Willadsen published his embryo
cloning work on sheep in the journal Nature. Since that time,
he has worked for several genetic companies in the United States
and Canada. As early as 1982 Willadsen began cutting-edge cloning
research using embryos which were developmentally advanced. Rumors
of this work led Dr. Ian Wilmut to question the old dogma that
cloning differentiated and began his research on cloning from
advanced cells. Wilmut cloned the first animal from an adult cell
in 1997. Dr. Willadsen's current work is on methods to freeze
mouse and human embryos and on rejuvenating human embryos that
have failed to develop. He believes that human cloning will happen
in the future if it has not already accidentally occurred in infertility
clinics, though he admits the chances are very small.
Coghlan, Andy. (1997). "Will
Cloned Cows Rise from the Dead?" New Scientist. March
8, 1997, 153(2072)
Abstract: Henrik Callesen and colleagues have been trying to clone
cows using donor cells from cows that have been dead for about
half an hour. To begin the experiment, adult cells and immature,
unfertilized eggs called oocytes are removed from the cows' ovaries.
Next, the
oocyte is emptied of its DNA. Using electricity, this empty cell
is fused with an adult ovary cell and allowed to grow for 1 week.
The researchers are still trying to get the cells to reach a pre-embryonic,
division stage called a blastocyst. When a blastocyst develops,
Callesen will transfer the cloned cell into the womb of a cow
where it is expected to develop normally.
Alan Trounson and an Australian team are also trying to clone
cows. They get their donor either from fetuses or the ovaries
of live cows. Like Callesen's team, they have not achieved a pregnancy
yet. Trounson believes cloned cows could be used to produce drugs
like interferon more cheaply than standard methods. Cloning cows
from dead cells has raised public concern that dead humans might
be cloned. According to Trounson, cloning dead humans is not being
considered by the scientific community. Cloning dead people would
be extremely difficult since the DNA must be perfect and cells
decompose very quickly after death.
Gordon, Meg. (1997). "Suffering
of the Lambs." New Scientist. 154(2079): 16-17.
Abstract: Biotechnology companies like PPL Therapeutics in Scotland
raise livestock that have been genetically engineered to produce
milk with great medicinal value. At PPL, sheep have been manipulated
to secrete in their milk a protein called alpha-1-antitrypsin,
which helps to treat cystic fibrosis. Genetic engineering for
livestock has proven less than efficient, with some animals producing
low yields, and some with high yields. If future generations of
genetically engineered livestock could be cloned from a current
herd's top producer, the technique that recently created Dolly
the sheep, pharmaceutical companies involved in such research
would see their profits increase markedly. Now that cloning has
the potential to turn a rare experimental procedure--the creation
of transgenic animals--into a profitable, industrial process,
ethicists, geneticists, agriculturalists, and animal welfare activists
are warning that the new technology could encourage serious abuses
of animal welfare. Current laws on transgenic animals are nonspecific.
In the U.S., once an animal has been engineered to produce a protein
that is to be tested as a medicine, its welfare is largely regulated
by the Food and Drug Administration (FDA) under the same laws
that would govern a vat of cells. There are no safeguards in the
U.S. to prevent a company from creating large numbers of transgenic
animals before the company is certain that the foreign gene will
not harm the animal or its offspring. Out of 10,000 eggs injected
with foreign DNA, only about three make it to adulthood and produce
the desired protein in sufficiently high quantities. The techniques
used to create Dolly offer two possible shortcuts. One could create
just one transgenic animal by conventional techniques and then
clone it ad infinitum to create flocks for drug testing, or because
Dolly's genetic material came from cultured cells from adult sheep,
the genetic manipulation could be done in these cells. Researchers
concede that they have more work to do before cloning and transgenics
can be combined. Some academics argue that the laws covering the
protection of animals used in these technologies are not comprehensive
enough. Some suggest that the only way to ensure the avoidance
of abuses may be to have transgenic animals monitored constantly.
Wright, Robert. (1997). "Can
Souls Be Xeroxed?: Your Clone Might Be Eerily Like You.
Or Perhaps Eerily Like Someone Else." Time. 149(10):
73.
Abstract: What would the world be like if human cloning becomes
a reality? Most likely people with high self- esteem would be
the only ones using it--people who think the world needs more
people just like them. The assumption is that psyches get copied
along with the
genes. However, although some people may be genetically prone
to high self-esteem, everyone's self-esteem depends greatly on
social feedback. Early in this century an effort at behavioral
genetics divided people into classes such as mesomorphs (physically
robust and psychologically assertive) and ectomorphs (skinny,
nervous, and shy). These generalizations don't necessarily mean
that ectomorphs have genes for shyness. It may just mean skinny
people tend to get pushed around more and their personality adapts.
Another assumption people have is that if they reared their clone
they would experience an uncanny empathy with them. The truth
is if you tried hard enough you could similarly empathize with
people who weren't your clone by relating common experiences.
The cause of this clonal empathy wouldn't be that your inner life
was exactly like your clone's. It would be seeing that familiar
face, reminding you that you and your clone were essentially the
same, driven by the same hopes and fears. You may feel you share
the same soul because, in a sense, you share the same soul with
everyone.
Kahn, Axel. (1997). "Clone
Mammals...Clone Man?" Nature. 386(6621): 119.
Abstract: In 1997 researchers cloned viable sheep from adult cells.
Now, researchers are questioning the possibility of human cloning.
There is no reason why humans should behave very differently from
other mammals where cloning is possible. The cloning of an adult
human could become feasible using the techniques reported. The
topic of human cloning has been greatly debated. Scientists question
the medical and scientific justification for cloning humans. Previous
debates have identified the preparation of immuno-compatible differentiated
cells lines for transplantation, as one potential indication.
Researchers imagine everyone having their own reserve of therapeutic
cells that would increase their chance of being cured of various
disease, such as cancer, degenerative disorders, and viral or
inflammatory diseases. Applying the technique used in sheep directly
to humans would yield a clone of the father and not a shared descendant
of both the father and mother. Nevertheless, for a woman the act
of carrying a fetus can be as important as being its biological
mother. The extraordinary power of such maternal reappropriation
of the embryo can be seen from the strong demand for pregnancies
in post-menopausal women, and for embryo and oocyte donations
to circumvent female sterility. Moreover, if cloning techniques
were ever to be used, the mother would be contributing her mitochondrial
genome.
Anderson, Ian. (1997). "Will
Many Clones Make Light Work." New Scientist. March
15, 1997, 153(2073)
Abstract: Scientists working on the cloning of animals are moving
toward mass production. Australian scientists have created almost
500 genetically identical embryos, but they must still prove that
mass-produced embryos, can result in healthy pregnancies. This
technology could be combined with the technique for cloning adult
animals pioneered in Scotland. This would make possible the creation
of hundreds of copies of an adult animal. The Scottish team succeeded
in cloning a single lamb from 277 sheep udder cells. There are
several groups around the world currently experimenting with cloning.
The Australians are collaborating with a farmer-owned cooperative
interested in new technologies for animal breeding. They are developing
a production process for genetically identical embryos. Embryos
are produced and left for four or five days to divide into a ball
of cells called a blastocyst. The researchers then separate up
to 30 cells and, like the Scottish team, use an electric current
to fuse them with the cytoplasm of an unfertilized egg cell that
has had its own DNA removed. The resulting genetically identical
embryos are grown and separated repeatedly. The egg cells are
taken from cow ovaries obtained at slaughter houses. Previously,
no group had produced more than 100 embryos from a single blastocyst
but the Australians' record is 470. The key factor is thought
to be providing sufficient cytoplasm for each embryo. Most of
the embryos produced by the Australians have not been implanted
in surrogate mothers, but six calves, including one set of twins,
have been born using the new technology. These calves did not
come from the 470 genetically identical embryos. Researchers are
attempting to find a technique for the production of cattle that
is more efficient than artificial insemination (AI). AI allows
farmers to fertilize many cows with the sperm of a bull with desirable
genetic characteristics, but the cows may be of variable genetic
quality. The new technique should permit fertilization of an elite
cow's eggs with sperm from a prize bull and subsequently produce
hundreds of genetically identical calves. A member of the Scottish
group said that the combination of this technique with his group's
adult cloning technique should have some useful applications.
However, he added that the Australian group has yet to show that
their mass-produced embryos produce healthy pregnancies and offspring,
since cloned embryos often fail to develop.
Marshall, Eliot. (1997). "Mammalian
Cloning Debate Heats Up." Science. 275(5307): 1733.
Abstract: In response to embryologist Ian Wilmut's cloning of
Dolly, a Scottish mountain sheep, the National Bioethics Advisory
Commission (NBAC) began hearings on the cloning of humans. President
Clinton banned all federally funded research until NBAC provides
an opinion expected by the end of May 1997. Although the cloning
of humans presents ethical questions, Harold Varmus, director
of the National Institutes of Health, is focusing on the technological
benefits of cloning. At a press conference, Varmus suggested that
the technique might provide insight into how cells of the early
embryo regulate gene function. The information could provide keys
to enable scientists to activate good genes or deactivate bad
genes. Varmus also added that the technique might enable researchers
to create custom-designed transgenic animals that can mass produce
human proteins, clotting factor, fibrinogen, or tissue for organ
transplants. Varmus and Wilmut have asked Congress to wait for
the results of the NBAC review before enacting new laws. However,
three bills have already been introduced. One bill would prohibit
federal funding for any research or project that involves the
use of a human somatic cell for the process of producing a human
clone. Another bill outlaws the use of a human somatic cell for
producing a human cell. And a third bill bans the use of federal
spending for research into human cloning.
Stephenson, Joan. (1997). "Threatened
Bans on Human Cloning Research Could Hamper
Advances." Journal of the American Medical Association.
277(13): 1023-1026.
Abstract: The announcement of a cloned sheep from the DNA in a
single udder cell of a 6-year-old ewe has ignited a debate on
ethical implications of cloning and sparked the imaginations of
researchers regarding the scientific implications and potential
of cloning. Several countries, including the U.S., have banned
the cloning of human beings. There is definitely a need to analyze
cloning because of ethical and legal issues related to reproduction,
genetic manipulation, and rights to privacy as well as the public's
initial suspicion concerning any new technology that may play
a role in the area of sexual reproduction. Many researchers feel
that a temporary ban on cloning and an analysis by the National
Bioethics Advisory Commission would reassure the public and forestall
a rush to enact laws that go far beyond banning the cloning of
whole individuals. Some researchers are worried that a broadly
worded ban would block basic and applied research using cloning
techniques on human cells, because this type of research has the
potential to answer important questions in cell regulation and
could pave the way for therapeutic advances.
Kluger, Jeffrey. (1997). "Will
We Follow the Sheep?" Time. 149(10): 66, 70-72.
Abstract: Recently Scottish embryologists announced that they
had succeeded in cloning a sheep from a single adult cell. Even
though this breakthrough took years to accomplish, science seems
to have been the easy part. The social and philosophical implications
are just beginning. One obvious question is how will the new technology
be regulated? President Clinton recently took a step toward answering
this and other questions by charging a federal commission with
the task of investigating the legal and ethical implications of
the new technology and reporting their findings within 90 days.
Also, the House subcommittee on basic research will hold a hearing
to address the same issues. Of all the reasons for using this
new technology, pure ego is the most disturbing. Some argue that
cloning is not very different from genetically engineering an
embryo to eliminate a genetic disease like cystic fibrosis, or
from in vitro fertilization. More palatable than the ego clone
to some bioethicists is the medical clone, a baby created to provide
transplant material, like bone marrow, for the original. If anything
will prevent human cloning from becoming a reality, it is that
science may not be able to clear the ethical high bar that would
allow basic research to get under way. Even if governments ban
cloning outright, it will not be so easy to police what goes on
in private or pirate laboratories. Science needs to get its ethical
house in order quickly.
Nash, J. Madeleine. (1997). "The
Age of Cloning: A Line Has Been Crossed and
Reproductive Biology Will Never Be the Same for People or for
Sheep." Time.
149(10): 62-65.
Abstract: Researchers at the Roslin Institute near Edinburgh,
Scotland, have made possible what seemed like a scientific impossibility.
From a cell in an adult ewe's mammary gland, embryologist Ian
Wilmut and his colleagues created a lamb named Dolly, who is a
carbon copy of her mother. She is in essence her mother's identical
twin. Now that this biological barrier has been crossed, many
exciting possibilities exist, from propagating endangered
animal species to producing replacement organs for transplant
patients. But the possibility of misuse of this technology exists
as well. Cloning mammals by splitting embryos in half is not new,
but cloning mammals from cells that are not embryonic is. To create
Dolly, the Roslin team took cells from the udder of a Finn Dorset
ewe. To stop them from dividing, the researchers starved the cells
of nutrients for a week. An unfertilized egg cell was taken from
a Scottish Blackface ewe. The nucleus, with its DNA, was sucked
out, leaving an empty egg cell containing all the cellular machinery
necessary to produce an embryo. The two cells were placed next
to each other and an electric pulse caused them to fuse together.
A second pulse mimicked the burst of energy at natural fertilization,
jump-starting cell division. About one week later, the resulting
embryo was implanted in the uterus of another Blackface ewe. After
a gestation period, the pregnant Blackface ewe gave birth to Dolly,
who is genetically identical to the original donor. Undoubtedly,
this breakthrough has raised more questions than it has answered.
So far, there is no talk of cloning humans, but policymakers will
need to find ways to prevent abuses without blocking scientific
progress.
Cohen, John. (1997). "Can
Cloning Help Save Beleaguered Species?" Science. 276(5317):
1329-1330.
Abstract: Since the successful cloning of a sheep ("Dolly")
in Scotland, conservation biologists are beginning to seriously
explore the possibilities--and ramifications-- of cloning endangered
species. Since 1975, the San Diego Zoo's Center for Reproduction
of Endangered Species (CRES) has been storing fibroblasts frozen
in liquid nitrogen from several endangered species. The cells,
originally destined for genetic study, could realistically be
used one day to clone live animals. Kurt Benirschke, who launched
the cell storage program, would like to see as many cells from
endangered species around the world saved as possible. CRES geneticist
Oliver Ryder believes that mixing genetic material from long-dead
animals (through cloned creatures) with that of surviving members
of a species could insure otherwise lost genetic diversity within
a species. This practice could enable zoos to retain smaller herds
while retaining genetic diversity. For animals that don't breed
well in captivity, cloning offers a needed resource. Some biologists
fear that cloning as a way to preserve species could divert funds
and efforts from other vital wildlife conservation efforts such
as habitat preservation. Others point out the high rate of failure
in assisted breeding efforts even in familiar domestic species
(Dolly required 277 attempts) and the exorbitant cost to a branch
of research already struggling with limited funding makes cloning
undesirable as well as unrealistic. But most agree that cloning
may prove to be the only remaining "window of opportunity"
for some species on the brink of extinction.
Fackelmann, K. A. (1994). "Embryo
Research Panel Ignites Debate." Science News. 146(14):
212.
Abstract: A National Institutes of Health (NIH) advisory panel
has released its proposed guidelines for federally funded research
on very early human embryos. In general, the panel would allow
experiments on embryos up to the 4th day after fertilization,
a time when the nervous system and various organs start to develop.
The U.S. has had a de facto ban on federal funding of any research
involving human embryos since 1980. However, in 1993 Congress
passed a law that paved the way for federal review and funding
of such projects. Currently, embryo research in the U.S. is funded
privately. The 19-member panel also recommended federal support
for research on "spare" embryos, those that go unused
at in vitro fertilization clinics. The panel also approved an
experimental technique called preimplantation diagnosis, which
involves drawing off one or two cells from a very young embryo
in order to diagnose certain genetic diseases, such as cystic
fibrosis. The panel okayed the practice of determining the gender
of embryos in order to avoid a sex-linked genetic disease, such
as hemophilia. The group advised against the sexing of embryos
for any other purpose. Another procedure the panel approved was
the creation of "parthenotes," or human eggs that have
been stimulated with chemicals or an electric shock to divide.
These dividing cells are not fertilized with a sperm and are grossly
abnormal. However, researchers believe studies of such eggs may
lead to a better understanding of the paternal role in fertilization.
The panel came out against the transfer of human embryos to the
wombs of animals for further development and urged a prohibition
on crossing human and animal sex cells. The panel also recommended
against providing federal money for twinning, or cloning human
embryos, which could result in the birth of identical twins or
triplets. Now the report gets passed on to another NIH advisory
committee, which will consider the initial panel's recommendations
as well as public comments. It will then send its recommendations
NIH director Harold Varmus who will make the final decision.
Voelker, Rebecca. (1994). "A
Clone by Any Other Name Is Still an Ethical Concern."
Journal of the American Medical Association. 271: 331-332.
Abstract: Public and private groups were to convene in February
1994 to lay the groundwork for future policy recommendations on
how human embryo research should proceed and the types of clinical
applications that may be considered appropriate. Much of the current
controversy over such research has been fueled by intense media
speculation and concerns surrounding laboratory efforts to duplicate
polyploid embryos. Federally sponsored research on in vitro fertilization
(IVF) has been held in abeyance since 1980 until last year, when
Congress and the Clinton administration allowed such research
to again receive federal support. Also in February, the National
Institutes of Health (NIH) human embryo research panel was scheduled
to recommend appropriate directions for government-sponsored research
and guidelines for carrying it out. The group was not to consider
research on or the ethics of human germ-line gene modification.
Two weeks after the NIH has concluded its initial discussions,
the private group National Advisory Board on Ethics in Reproduction
(NABER) will meet to debate the scientific and ethical questions
arising from research on the cloning of polyploid embryos done
at George Washington University Medical Center in Washington,
DC. Specifically, NABER wants to know more about how the university
review board decided to allow the experiment to proceed. Much
scientific debate has focused on what a clone really is. Some
scientists use a fairly broad definition: A clone is an identical
replication, a duplicate copy. Others define cloning as taking
the nucleus of a cell from the body of an adult and tranferring
it to an unfertilized egg, destroying the genome of the oocyte
of the egg, and letting it develop. This process is different
from that done at George Washington, which has also been referred
to as twinning. The process is also different from nuclear transportation--taking
a nucleus from a 50- to 80-cell embryo and transplanting it to
an unfertilized egg from which the nuclear material has been removed.
Critics of the George Washington research argue that the duplicates
produced could not have been identical because, among other factors,
the chromosomes in daughter cells are not identical. The university
researchers admit that they did not perform a genetic analysis
of embryos produced in their laboratory to confirm whether they
were identical copies. The researchers say they will not proceed
with their research until the ethical debate matures and possibly
provides some guidelines. They also note that their research has
provided a unique opportunity for ethicists, scientists, physicians,
and patients: The procedure can be debated well in advance of
being used in a clinical setting.
Fackelmann, K.A. (1993). "Researchers
'Clone' Human Embryos." Science News. 144(18):
276.
Abstract: For the first time, scientists have "cloned"
human embryos, a step that has raised a host of ethical and scientific
issues regarding the brave new world of reproductive research.
Although it is not unusual for researchers to clone animal embryos,
this marks the first known attempt to split a human embryo into
individual cells, a technique more accurately described as "twinning."
Twinning could have the practical application of increasing the
chances of pregnancy among women who have undergone in vitro fertilization.
The scientists, from George Washington University in Washington,
DC, conducted their experiment with 17 very young, abnormal human
embryos which could not be viable. They stripped the embryos of
their tough coating called the zona pellucida then separated the
individual cells which ranged from two to eight cells per embryo.
The 48 resulting cells were coated with artificial shells and
allowed to grow. The cells split from a two-cell embryo appeared
best able to divide, with some reaching the 32- cell stage of
development. These results suggest that this process could be
used to create viable embryos if used with normal starting embryos.
The question which must be answered now is whether or not the
technique should be used.
Miller, S.K. and Gail Vines. (1993).
"Human Clones Split Fertility Experts." New Scientist.
October 30, 1993, 140(1897)
Abstract: American researchers have cloned human embryos in an
experiment aimed at adding new options to the armory of the fertility
clinic. Researchers from the George Washington University Medical
Center performed the experiment on embryos obtained from women
undergoing IVF (in vitro fertilization) treatment. These embryos
had the fatal defect of having been fertilized by more than one
sperm, giving them three or more sets of chromosomes. The researchers
split 17 embryos, each containing two to eight cells, then coated
the individual cells with a gel-like substance to form an artificial
zona pellucida, the protective membrane around an embryo. The
most successful clones, which reached the 32-cell stage before
dying, developed from embryos which had been split at the two-cell
stage. The ultimate goal of the work is to increase the odds of
pregnancy in women of low fertility. The IVF current practice
is to give women hormones which induce them to produce multiple
eggs which are then removed, fertilized externally and then implanted.
Cloning would replace the need for hormone treatment. The U.S.
has no national policy or agency regulating embryo research, although
a long-standing ban on federal funding for such research was lifted
by President Clinton when he took office. All parties involved
realize the ethical implications of this type of research. If
viable cloned embryos were frozen, parents could give birth to
a twin at a later date, perhaps to replace a dead child, or to
provide bone marrow or other organs for a sick child. Embryo splitting
is considered unethical and is illegal in Britain.
Elmer-Dewitt, Philip. (1993). "Cloning:
Where Do We Draw the Line?" Time. 142(19): 64-70.
Abstract: In a landmark experiment at George Washington University,
researchers Robert Stillman and Jerry Hall duplicated a human
embryo. As part of a fertility treatment, eggs were removed from
a woman and fertilized in a Petri dish. Some of these eggs were
fertilized by more than one sperm--an abnormal condition. One
such abnormal cell divided in two as the first step in development.
The coating was removed with an enzyme, and the two cells were
separated. Using a novel technique, artificial zona coatings were
added, allowing development to proceed. The cells continued to
divide, forming genetically identical embryos. Development stopped
after six d, partly because the embryo was abnormal. To Hall and
Stillman, human cloning is simply the next step in the logical
progression that started with in- vitro fertilization and is driven
by a desire to relieve human suffering--in this case, the suffering
of infertile couples. But it was the start of the fiercest scientific
debate about medical ethics since the birth of the first test-tube
baby 15 yr. ago. Many of the uses envisioned for cloning are not
particularly farfetched compared with things that are already
happening. A few years ago, faced with the news that their daughter
was dying of leukemia, the father braved a vasectomy reversal
and the mother a pregnancy at 43 to have a child born for the
purpose of providing the bone-marrow transplant that saved the
older child's life. Husband and wives who have been through in-vitro
fertilization with some embryos left over have had to wrestle
with the fact that they have a potential human being stored on
ice. When the profit motive enters into the equations, ethical
considerations tend to be forgotten. And private profit drives
the infertility business in the U.S. There are already catalogs
that list the characteristics of sperm donors--including one made
up of Nobel prizewinners. Most people seem to respond to the idea
of human cloning at a fundamental level. In a TIME/CNN poll, 58%
said they thought cloning was morally wrong, while 63% said they
believed it was against God's will. On an international front,
France, Germany and Japan expressed disapproval. More than 25
countries have commissions that set policy on reproductive technology.
In October, a report by the Congressional Office of Technology
recommended that the government step in. Under President Carter,
a presidential commission was established that developed broad
policy guidelines in some of the most controversial issues in
medicine, such as deciding when brain death has occurred or when
it is ethically correct for a doctor to withhold treatment. The
commission was disbanded in 1983. It is now likely that some kind
of national board will be established during President Clinton's
watch.
Nash, J. Madeleine. (1993). "They
Clone Cattle, Don't They?" Time. 142(19): 68.
Abstract: To see the future of cloning, one could look at the
livestock industry, the proving ground for reproductive technology.
More than a decade has passed since the first calves, lambs, and
piglets were cloned, and yet there are no dairy herds composed
of carbon-copy cows, no pigpens filled with identical sows. While
copying particular strains of valuable plants such as corn and
canola has become an indispensable tool of modern agriculture,
cloning farm animals, feasible as it may be, has never become
widespread. Even simple embryo splitting, the technique used by
the George Washington University researchers on human cells, is
too expensive and complicated to take off commercially. But people
have tried to turn livestock cloning into a booming branch of
agribusiness. Wisconsin -based American Breeders Service, a subsidiary
of W.R. Grace & Co., now owns the rights to cattle-cloning
technology developed by Granada Biosciences, a once high-flying
biotech firm that went out of business in 1992. The process calls
for single cells to be separated from a growing calf embryo. Each
cell is then injected into an unfertilized egg and implanted in
the womb of a surrogate cow. Because the nucleus of the unfertilized
egg is removed beforehand, it contains no genetic material that
might interfere with the development of the embryo. In theory,
then, it ought to be possible to extract a 32- cell embryo from
a prize dairy cow and use it to produce 32 identical calves, each
brought to term by a less valuable member of the herd. In practice,
however, only 20% of the cloned embryos survive, meaning that
instead of 32 calves, researchers generally end up with only five
or six. While the success rate may improve, at present this method
of cloning does not seem much better than embryo splitting, which
typically produces twins and sometimes triplets. There have been
other problems as well. Some of the calves produced have weighed
so much at birth that they have had to be delivered through caesarean
section. When cattle cloning is perfected, it may not be welcomed
down on the farm. Using cloning to create large numbers of identical
calves runs counter to what breeders strive to do. Breeders want
to create cows better than even their prizewinners, and the only
way to do that is by constantly reshuffling the genetic deck with
a fresh supply of genes.
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