a.k.a. cell nuclear replacement
Adult DNA cloning topics covered:
Cloning is the production of one or more individual plants or animals that are
genetically identical to another plant or animal.
Adult DNA cloning involves removing the DNA from an embryo and
replacing it with the DNA from an adult animal. Then, the embryo is
allowed to develop into a new animal with the same DNA as the donor.
It has been used to clone a sheep and other animals. It has not been tried on humans.
With the exception of the sperm and egg, every cell in the body contains all of the
genetic material in its DNA to theoretically create an exact clone of the original body.
But cells have been "biochemically programmed to perform limited functions."
1 The other functions are turned off. Most scientists had
believed that such differentiated cells could not be reprogrammed to be capable of
behaving as a fertilized egg.
In the case of the sheep "Dolly" (described below), a cell was taken from
the mammary tissue of a mature 6 year old sheep while its DNA was in a dormant state. It was
fused with a sheep ovum which had had its nucleus removed. The "fertilized" cell
was then stimulated with an electric pulse. Out of 277 attempts at cell fusion, only 29
began to divide. These were all implanted in ewes. Thirteen became pregnant but only one lamb,
Dolly, was born.
Similar experiments to clone mice were initially unsuccessful. One speculation
was that the
DNA in sheep may not be used by the cells until after three or four cell divisions have
completed. This would give the ovum "sufficient time to reprogram the DNA from
[its original] mammary cell functions to egg cell functions."
Both human and mouse use the DNA after the second cell division. So, some researchers had
predicted that humans as well as mice may not be "clonable". However,
mice were successfully cloned later. Thus, cloning of humans might also be
Scientists wondered whether "Dolly" would be fertile. Some cloned frogs are
infertile. Also, cells seem to have an internal clock that causes them to die off after a
normal life. Since Dolly was conceived from a 6 year old cell, her life expectancy may be
reduced from about 11 to only 5 years. This did not take place. Dolly, currently
4.5 years of age, continues to live a normal life.
This essay continues below.
This was assumed to be impossible in all mammals, until it was achieved in 1996-JUL by a
scientist from the UK, Dr. Ian Wilmut of the Roslin Institute in Roslin, Scotland.
News of the experiment was communicated to the press on 1997-FEB-23. "Dolly," a
seven-month old sheep, was displayed to the media; she is the first large cloned animal
using DNA from another adult. Since Dolly's conception, the Institute has successfully
cloned seven sheep of three breeds. The technique that they developed can probably be applied
to other domesticated mammals, perhaps including humans.
On 1997-MAR-4, apparently in reaction to "Dolly", President Clinton ordered a
widespread ban on the federal funding of human cloning in the US. Research continues in
On 1998-JUL-22, Dr. Ryuzo Yanagimachi of the University of Hawaii announced the cloning of
mice. The team had produced 22 mice; seven of them are clones of clones from the cells of a
Japanese researchers from Kinki University in Nara, Japan cloned 8 calves from a single
adult cow's DNA. They used techniques similar to that which produced "Dolly."
Four died shortly after birth due to what the researchers called "environmental
factors." Their study was published in the issue of Science magazine published
On 1998-DEC-14, researchers at the Infertility Clinic at Kyeonghee University in Korea
announced that they had successfully cloned a human. 2
Kim Seung-bo and Lee Bo-yeon took an ovum from a woman, removed its DNA and inserted a
somatic cell from the same 30 year old woman. Their report states: "We were able
to confirm division up to the fourth cell stage, the stage of embryo development when a
test tube embryo is usually placed back in the uterus, where it then further develops into
a fetus." The goal of their research was not to clone humans, but to clone
specific, genetically identical organs for human transplant. They did not implant the
morula into a human uterus because of ethical considerations. They destroyed it. The
Korean Federation for the Environmental Movement (KFEM) immediately issued a
statement criticizing the study. Members of the Life Safety Ethics Association
held a protest demonstration in front of the university.
Public opinion is having a chilling effect on cloning research in North America. Dr.
Alan DeCherney of the University of California at Los Angeles said that if anyone
tried to clone humans, they would "become the Dr. Kevorkian of reproduction."
By the end of the year 2000, eight species of mammals have been cloned,
including mice, cows, rhesus monkeys, sheep, goats, pigs, and rats. Between 3,000 and 5,000
cloned animals have been produced to date. 3
Current speculation is that the cloning process seems to create random
errors in the expression of individual genes. The egg must have its genes
reprogrammed in minutes or hours during the cloning process. Ova normally
take years to ripen naturally in the ovaries. It appears that the
extremely fast rate of programming can produce random errors in the
clone's DNA. 4
One of many concerns with human cloning is that cloning of animals
sometimes cause fetal overgrowth (aka large-offspring syndrome.) The
fetus grows unusually large and generally dies just before or after birth.
They have under-developed lungs and reduced immunity to infection. Duke
University researchers announced on 2001-AUG-15 that this particular
problem would not exist in humans. The DNA of all primates, such as
humans, monkeys and apes, have two copies of a gene that regulates fetal
growth, whereas almost all other animals have only one. This spare copy
should prevent fetal overgrowth in cloned human fetuses. Randy Jirtle,
professor of radiation oncology at Duke University in Durham, NC, said: "It's
going to be probably easier to clone us than it would be to clone these
other animals because you don't have this problem -- not easy, but easier.''
7 Kevin Eggan, of MIT's Whitehead Institute works
with cloned mice. He called the Duke study "interesting from the
perspective of the evolution of imprinting genes." But he cautioned
that there is no proof that abnormally large babies are born as a result
of this one genetic difference. His lab has a "four-times normal size"
mouse clone, which has normal IGFR2R genes. He suggests that there are
other factors that can contribute to abnormal development in clones.
Plans to attempt human DNA cloning:
Richard Seed, a physicist from Illinois, attempted to establish a human cloning
clinic. 5 He claimed on 1998-JAN-7 that he was "90%
complete" in hiring a team of experts to attempt the cloning of a human being,
following the experiments on "Dolly." If successful, the resultant child would
have identical DNA to one of its parents. Lord Robert Winston, a London based fertility
expert who helped produce the first test-tube baby in 1978, said: "My first
reaction is that here is somebody who is trying to make a quick buck off of
self-advertising, because of course there is no way you could clone a human being safely
at this point. I think the man is clearly unhinged and I don't think he is to be taken
seriously." Marian Damewood, a member of the board of the American Society
for Reproductive Medicine said: "I have very serious reservations about
cloning human beings." The Society has declared a 5 year voluntary ban on
cloning humans. Mr. Seed responded: "I can't really answer the critics who think
it's a bad idea. They'll never be persuaded. As far as I'm concerned, they have rather
small minds and a rather small view of the world and a rather small view of God."
6 Dr. Seed apparently did not succeed in his
As of 2001-AUG, there are two publicized projects underway to clone
humans. There may be others which are secret:
|Dr. Panayiotis Zavos of the Andrology
Institute in Lexington KY and Dr. Severino Antinori, a fertility
doctor in Rome announced in early 2001 that they want to proceed with the cloning
of humans. Professor Antoniori announced in early 2001-AUG that he
intends to start cloning human embryos before the end of 2001.|
|".. a religious sect called the
Raelians insists it will shortly undertake the same project. The Raelian
sect believes, among other things, that human beings were created in
laboratories by extra-terrestrials, and that the resurrection of Jesus
was a cloning procedure! Donors and surrogate mothers have already lined
up to pay $250,000 for the actual cloning experiment." 11|
"In an effort to stall these
attempts, Congress is planning to pass a bill banning human cloning by any
organization in the United States. However, it is unlikely that this will
prevent these efforts from being made elsewhere." 11
On 2001-AUG-14, Nobel Prize-winning scientist Sir Joseph Rotblat said that
our understanding of cloning is "too meager" at this time to succeed. He
suggested that many of the scientists involved are motivated by money. He
said: "Inevitably the problems will be overcome, and it's then that the
real ethical problems begin." He suggested that ethics evolve: "Ethics
are not absolute. Look at in-vitro fertilization. This was originally
considered unethical but is now widely accepted..."I feel that this
[cloning], too, will become acceptable."
In early 2002-APR, Dr. Severino Antinori announced that a woman who
joined his program for infertile couples is now eight weeks pregnant with
a fetus derived by human reproductive cloning. Although such cloning is
banned in Italy where he lives, he was allegedly able to go to another
country to perform the experimental technique. If the woman's pregnancy
produces a live newborn, it will probably suffer from one or more serious
genetic disabilities. 12
Surprisingly, some researchers do not seem to be deterred by the high
levels of mortality, deformities and other genetic problems observed in
animal cloning. At a National Academy of Sciences, three human
cloning researchers spoke. "One Kentucky-based researcher, for example, offered only a vague assurance
that cloning for human fertility purposes wouldn't be done if it couldn't be
done right, and then angrily objected to being lectured by a scientist who
wanted more of an answer. Another, a chemist who directs a Bahamas company and
belongs to a [Raelian] religious sect that seeks cloning, made the extreme claim that
is a fundamental right to reproduce in any way you want.' " 10
Some say yes:
|Some talents seem to be genetically influenced. Musical ability seems to run in
families. Cloning using the DNA from the cell of an adult with the desired traits or
talents might produce an infant with similar potential.|
|A heterosexual couple in which the husband was completely sterile could use adult DNA
cloning to produce a child. An ovum from the woman would be coupled with a cell from the
man's body. Both would contribute to the child: the woman would provide the
"factory" for creating cells; the man would provide the "genetic
information." They might find this more satisfactory than using the sperm of another
|Two lesbians could elect to have a child by adult DNA cloning rather than by artificial
insemination by a man's sperm. Each would then contribute part of her body to the
fertilized ovum: one woman would donate the ovum, which contains some genetic material in
its mitochondria; the other woman the nuclear genetic material. Both would have parts of
their bodies involved in the conception. They might find this more satisfactory than
in-vitro fertilization using a man's sperm.|
Some say no:
|There is no guarantee that the first cloned humans will be normal. The
fetus might suffer
from some disorder that is not detectable by ultrasound. They may be born disabled.
Disorders may materialize later in life. Such problems have been seen
in other cloned mammals. There is no reason to assume that they will
not happen in humans.|
|Cells seem to have a defined life span built into them. "Dolly" was created
from a cell that was about six years old; this is middle age for a ewe.
There were some indications that
Dolly's cells were also middle-aged. She was believed to be, in essence, about six years old when she was
born. She was expected to live only for five years, which is shorter than the normal life span
of 11 years. If this is also true of humans, then cloned people would have a reduced life
expectancy. The cloning technique could take many years off their life.
[These fears proved to be unfounded. "Dolly" has grown into
a comfortable middle age with signs of normal aging for her age.]|
|Dolly was conceived using a ewe's egg and a cell from another ewe's body. It is
noteworthy that no semen from a ram was involved. If the technique were perfected in
humans, and came into general usage, then there would be no genetic need for men. All of the
human males could be allowed to die off. [The author of this essay is a male and does not
think kindly of such a future. However, some readers might not object to this
|Large scale cloning could deplete genetic diversity. It is diversity that drives
evolution and adaptation. It prevents an entire species from disappearing because of
susceptibility to a disease. [It is doubtful that cloning would ever be used at a level to
make this a significant threat.]|
|Some people have expressed concern about the effects that cloning would have on
relationships. For example, a child born from an adult DNA cloning from his father would
be, in effect, a delayed twin of one of his parents. That has never happened before and
may lead to emotional difficulties.|
|There are religious objections to cloning.
|Most pro-life supporters believe that a fertilized ovum is a
full human person. When its nucleus is removed during cloning, that
person is, in effect, murdered.|
|A secondary concern is the whole business of collecting surplus
embryos and simply storing them in a deep-freeze as a commodity.
|Some claim that cloned humans may be born without souls. They speculate that the soul
enters the body when a sperm fertilizes an ovum. Since there is no sperm involved in
cloning, perhaps the fetus would develop without a soul. There is no way to know whether a
soul is present; it has no weight, it cannot be seen, touched, smelled, heard, or detected
in any other way. In fact, many people believe that souls do not exist. Speculation on
this topic can never be resolved.|
At the current stage in cloning research using adult DNA, the random
appearance of genetic defects, noted above, appears to be an overwhelming
problem. Such dangers would seem to put an indefinite halt on all ethical
cloning of humans.
- Dr. Ray Bohlin, director of communications at Probe Ministries has written an
essay: "The Little Lamb That Made a Monkey of Us All - Can Humans be Cloned Like
Sheep?", 1997-MAR-7. See: http://www.probe.org/docs/lambclon.htm
- "Human Cloning Test Succeeds," Chosun-Ilbo newspaper,
- "Humans may be cloned 'Sooner than anyone thinks.' "
CNSNews.com at: http://www.mcjonline.com/news/01a/20010213e.shtml
- Gina Kolata, "Few cloning efforts work, scientists say,"
New York Times, 2001-MAR-25.
- "Cloning Proponent 'clearly unhinged,' scientist says",
Reuters News Agency, 1998-JAN-7
- Religion Today news summary,
- Will Dunham, "Scientists tout feasibility of human cloning,"
- "Human cloning easier than thought?," CNN, at:
- Peter Foote, "Scientist calls for debate on human cloning," Irish
Times, at: http://www.ireland.com/newspaper/
- "The cloning debates," Editorial at The Buffalo News. See:
- Prasad Venugopal, "The science and politics of genetic engineering,"
Political Affairs, Vol. 80, #7, 2001-JUL, at:
- "Reproductive Cloning: Just What The Doctor Ordered," Washington
Update, Family Research Council, 2002-APR-5.
Copyright ©1997 to 2004 incl. by Ontario Consultants on
Originally published: 1997-AUG-5
Last updated 2004-FEB-12
Author: Bruce A Robinson