5/8/01
human cloning
IMPORTANT SCIENTIFIC CLARIFICATIONS: As Congress begins the debate
regarding exactly what can be done to stop the spread of human cloning
research, experimentation with human embryonic persons and genetic
manipulation, the following clarifications by Dianne N. Irving, Ph.D.,
will be most helpful.
The issues surrounding the current debates on human embryonic stem cell
research, human embryo research, human cloning, etc., are still seriously
clouded with scientific inaccuracies and much confusion. Before any
further proposed legislation, guidelines, etc., make it through the
political processes and are finally adopted, I want to try in some small
way to try to clarify at least a few critical issues that I hope will help
people understand better what the real facts are, and to act accordingly.
All following statements are well documented in the scientific literature.
If there are any questions about these statements, or corrections to them,
please let me know. I would appreciate any feedback.
- The current popular distinction between "therapeutic cloning" (i.e.,
cloning human embryos for research purposes only) and "reproductive
cloning" (i.e., cloning human embryos that will be implanted into the
woman's womb) is a FALSE DISTINCTION, and should not be used as the
basis for any legislation, guidelines, etc. The distinction is one based
only on what is done with these newly existing human beings, not on what
they already are -- living human beings. A human being is a human being
is a human being -- whether it is then used in research or implanted in
a woman's womb. Therefore, BOTH "therapeutic cloning" and "reproductive
cloning" should be banned -- both in the public and in the private
sectors.
- Most of the proposed legislation and guidelines on cloning I have
seen ban ONLY one kind of cloning process -- i.e., "somatic cell nuclear
transfer." But there are several other methods of cloning too, including
parthenogenesis, back breeding, etc. -- even a long-term kind of cloning
by using DNA-recombinant germ-line "therapy." By being "silent" on these
other methods of cloning, the effect of the ban would be to allow these
other methods of cloning to go forward unfettered.
- Researchers want to use the "leftover" human embryos that have been
produced by IVF "therapy" for both stem cell research and for cloning
research. However, the early human embryos that are produced by IVF are
not usually frozen down at the blastocyst stage (the developing human
being 5-7 days post fertilization, which contain 100+ "pluripotent"
cells), but are usually much younger embryos containing only about 4-16
cells. These early embryonic cells are "totipotent." As long as these
totipotent cells are still part of the embryo they are indeed "stem
cells." But once these totipotent embryonic cells are separated from the
embryo by the researcher, they are no long "just stem cells," but rather
revert back to the single-cell embryonic zygote stage -- i.e., a HUMAN
BEING. It is a scientific fact that these "separated" totipotent cells
are fully capable of "healing" themselves and reverting back to the
zygote stage -- i.e., they are then new human EMBRYOS. (More precisely,
they can "heal" themselves to whatever prior state of differentiation is
needed to allow these new embryonic organisms, which are living human
beings, to survive). [See, for example, Bruce M. Carlson, Human
Embryology and Developmental Biology (St. Louis, MO: Mosby, 1994, pp.
39-41)]. This is in fact what happens in most natural monozygotic
twinning -- e.g., a single whole human embryo at, say, the 4-cell stage,
splits (fission), and those two groups of cells EACH become twins. So we
already have centuries of empirical proof in observing natural
monozygotic twinning that the separation of these early totipotent cells
of a single embryo can result in those separated cells reverting back to
whatever is needed to allow each cell or group of cells to maintain
their unity and be new human beings. Therefore, when proponents claim
that they just want to use these IVF frozen embryos to obtain their
"stem cells," and to then culture them in vitro, what they are really
doing when they separate these embryonic cells from the whole embryo is
creating more individual embryos who are living human beings, from which
they will culture more embryos who are living human beings. That is,
they will not be using "stem cells" and maintaining "stem cells" in
culture; they will be using living human beings and maintaining living
human beings in culture. However, since they are producing embryos (who
are living human beings), and continuing to use them in culture and in
research, then THIS IS HUMAN EMBRYO RESEARCH WHICH IS ALREADY BANNED BY
CONGRESS. Therefore human embryonic "stem cell" research is just another
form of human embryo research, and should be precluded by the current
Congressional ban.
- Similarly, it is a scientific fact that the immediate product of
human cloning is a newly existing human being (i.e., a single-cell
embryo or zygote). When a human embryo is cloned (by whichever cloning
technique), it too can then be used for research (so-called
"therapeutic" cloning). But using that human embryo for "therapeutic"
research IS HUMAN EMBRYO RESEARCH WHICH IS ALREADY BANNED BY CONGRESS.
Therefore "therapeutic cloning" is just another form of human embryo
research too, and should also be precluded by the current Congressional
ban on human embryo research.
- Finally, "fetal tissue transplant research" has been legalized, and
therefore removing "fetal stem cells" from aborted fetuses to use in
"fetal stem cell research" is now also legal. However:
- The cells removed from aborted fetuses for "fetal stem cell
research" are NOT necessarily FETAL cells, but are usually EMBRYONIC
cells removed from older embryos. (The embryonic period begins at
fertilization and extends until the end of 8 weeks post fertilization;
the fetal period begins at 9 weeks and extends until birth). That is,
what is being used are really embryonic cells, not fetal cells. So
even though "fetal tissue transplant research" is legal, "embryonic
transplant research" is not. It does not accurately fall within the
definition of "fetal tissue transplant research." Therefore, "fetal
stem cell research," which in reality is "embryonic tissue transplant
research," SHOULD NOT BE CONSIDERED LEGAL.
- It could also be argued that since they are really using embryonic
stem cells, rather than fetal stem cells, they are therefore also
performing HUMAN EMBRYO RESEARCH -- at least if they remove these
cells from embryos up to the 9th week post fertilization. The source
of these "fetal stem cells" are not fetuses but embryos, albeit
already dead ones.
- Also, those "fetal stem cells" are NOT somatic cells (which are
properly defined as the cells of the body EXCEPT the germ-line cells).
That is, these "fetal stem cells" are GERM-LINE CELLS, i.e., the
primitive sex cells -- which still contain 46 chromosomes. Therefore
these primitive germ-line sex cells can be fertilized using IVF, and
can be cloned as well. This provides a constant source of IVF-produced
and clone-produced human embryos (human beings) for all sorts of
research. But using such IVF produced human embryos or using
clone-produced human embryos would also BE HUMAN EMBRYO RESEARCH WHICH
IS BANNED BY CONGRESS.
- Furthermore, most of the cloning legislation and guidelines I have
seen only refer to the cloning of somatic cells without mentioning
these germ-line cells; and the definition of "somatic cell" used is
usually scientifically erroneous per se. They never mention that these
"fetal stem cells" are not somatic cells, but are the primitive sex
cells, and that they too still contain 46 chromosomes (because these
germ-line cells are still immature). Therefore these bills,
guidelines, etc., would simply not cover the cloning of "fetal stem
cells," but only the cloning of "somatic cells."
- So what should concern us? First, if they cloned these primitive
sex cells, by any method of cloning, the immediate product would also
be a new embryo -- a new existing human being. If they then used that
new embryo in research then that too would be human embryo research --
WHICH IS ALSO ALREADY BANNED BY CONGRESS.
Also, by being "silent" on what "fetal stem cells" really are, none
of the current bills, guidelines, etc., would prevent the use of these
early human embryos in either human embryo research, or in
"therapeutic" cloning (which is a form of human embryo research).
Also, these germ-line stem cells are the cells that they want to
use for DNA-recombinant GERM-LINE GENE "THERAPY" -- which scientists
themselves refer to as doing "positive eugenics." This research has
already been extensively performed using animals; the protocols are
already in the human embryology textbooks. [See, for example, William
J. Larsen, Human Embryology (New York: Churchill Livingstone, 1997),
pp. 22-28; Bruce M. Carlson, Human Embryology and Developmental
Biology (St. Louis, MO: Mosby, 1994), p. 41; Benjamin Lewin, Ed.,
Genes III (New York: John Wiley & Sons, 1987), pp. 353-354.]
Using these HUMAN primitive sex cells, or "germ-line cells," they
would insert new genes into either the primitive spermatozoon or
oocyte, and then create new embryos containing the new genes -- using
either IVF or cloning techniques. The progeny of these embryos would
all carry these new inserted genes, and pass them down from generation
to generation. DNA-recombinant germ-line gene therapy is a highly
controversial issue now, and so far has not been authorized by the
FDA, nor should it be.
Also, several "bans" and "guidelines" forbid the scavenging of
cadavers for "somatic cells" to be used in cloning. However, by being
"silent" on germ-line cells, it would still be possible to take the
primitive sex cells from even young children and adult (men and women)
cadavers, and use them in both IVF and in cloning as a means of
producing more living human embryos for research purposes only. That
is, these cells would not be "banned" by such efforts. But this TOO is
human embryo research, and is banned by Congress.
IN SUM: There is no real distinction between
"therapeutic" and "reproductive" cloning, and both should be banned, in
both the private and the public sectors. ALL cloning techniques should be
banned, not just somatic cell nuclear transfer cloning.
Further, according to the current Congressional ban on HUMAN EMBRYO
RESEARCH, human embryonic stem cell research, human cloning (using either
somatic cells or germ line cells) -- and possibly "fetal" stem cell
research -- should not be even permitted now BECAUSE THEY ARE ALL FORMS OF
HUMAN EMBRYO RESEARCH WHICH IS ALREADY BANNED BY CONGRESS.
Furthermore, the use of "fetal" stem cells would NOT fall under the
LEGAL definition of "fetal tissue transplant research" because it is NOT
fetal tissue but EMBRYONIC tissue -- on which the law is "silent."
Finally, these "fetal stem cells," which in reality are germ-line
cells:
- are not properly defined or covered by any legislation, guidelines,
etc.;
- could be used as a constant laboratory source of living human
embryos for research simply by fertilizing them using existing IVF
techniques (thereby bypassing the need for embryos left over after women
have undergone IVF "therapy"), or by cloning them;
- could be used in "germ-line therapy," which is now not permitted,
and which is in effect a form of "positive eugenics" and "long-term"
cloning via reproduction through the generations; and,
- could be obtained from human cadavers and used in IVF or cloning
because existing legislation and guidelines are silent on them.
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