Does Human Cloning Produce An Embryo?

In February 1997, Dr. Ian Wilmut and his team startled the scientific world by showing that the nucleus from an adult sheep's body cell could be used to produce a developing embryo that would grow into another, genetically identical sheep. There was no doubt whatever that this process ("somatic cell nuclear transfer") produces an embryo of the relevant species. As Dr. Wilmut said in his groundbreaking article: "The majority of reconstructed embryos were cultured in ligated oviducts of sheep... Most embryos that developed to morula or blastocyst after 6 days of culture were transferred to recipients and allowed to develop to term," etc. [I. Wilmut et al., "Viable offspring derived from fetal and adult mammalian cells," 385 Nature 810-813 (Feb. 27, 1997)].

Now that the discussion has turned to humans, political spokespersons for the biotechnology and pharmaceutical industries have decided to engage in a curious avoidance of the fact that somatic cell nuclear transfer using a human nucleus would produce a human embryo. There seem to be two reasons for this:

  1. some spokespersons maintain -- contrary to scientific evidence, the findings of the NIH Human Embryo Research Panel, and current federal law on embryo research -- that no human embryos should be called "embryos" for the first two weeks of existence.1
  2. because cloned embryos are seen as such useful research material for destructive experiments, current restrictions on embryo research etc. must be evaded by denying that an embryo produced by cloning deserves the name.
Thus euphemisms and misleading or inaccurate terms ("totipotent cell," "clump of embryonic cells," "unfertilized oocyte," etc.) have entered the political discussion. They are employed to conceal the fact that researchers want to be allowed to use cloning to produce and destroy human embryos. Biotechnology groups claim to oppose the cloning of "human beings" or "persons" -- but they reserve the right to conduct cloning experiments on human embryos and fetuses, so long as none is allowed to survive to live birth.

Fortunately, one can cut through the political evasions by looking at the professional literature -- including writings by those who support cloning of embryos for research purposes:

From an interview with James Thomson, Ph.D., the leading embryonic stem cell researcher in the United States:

"Q: The people who use nuclear transfer generally say that the technique is optimized for producing the stem cells rather than making babies. They would not want to equate this with the process that produces embryos that were fit for implantation, and they'd argue that they're using the reproductive process differently...

"A: See, you're trying to define it away, and it doesn't work. If you create an embryo by nuclear transfer, and you give it to somebody who didn't know where it came from, there would be no test you could do on that embryo to say where it came from. It is what it is.

"It's true that they have a much lower probability of giving rise to a child... But by any reasonable definition, at least at some frequency, you're creating an embryo. If you try to define it away, you're being disingenuous."
- Alan Boyle, "Stem cell pioneer does a reality check." MSNBC, (published online June 25, 2005),

"Religious conservatives and some other groups want to ban all human cloning, calling it an affront to the sanctity of life. Most of the scientific establishment wants to leave the door open to 'therapeutic' cloning, in which a clone is grown for a few days in the laboratory until it's an embryo of about 100 to 150 cells. At that point stem cells useful for research or treatment can be extracted."
- Antonio Regalado, "With Public Wary, Cloning Scientists Watch Their Words," Wall Street Journal (December 22, 2004), p. A1.

"Dr. Jose Cibelli, vice president of research at Advanced Cell Technologies (ACT), said 'This is the power of cloning: Cloning can take a body cell and turn it into an embryo. What we can do with this embryo depends on society. We can make an individual, or we can make a stem cell. These issues are currently being debated. Once we decide what to do, we'll have to live with it.'"
- Ed Oliver, "Cloning Researcher from ACT Lectures about Ethics at Holy Cross," Massachusetts News (published online May 3, 2002),

"[R]esearchers have proposed using SCNT [somatic cell nuclear transfer] to generate embryonic stem cells for persons who need tissue or organ transplants. ... If undertaken, the development of SCNT for such therapeutic purposes, in which embryos are not transferred for pregnancy, is likely to produce knowledge that could be used to achieve reproductive SCNT."
- The Ethics Committee of the American Society for Reproductive Medicine, 74 Fertility and Sterility 5 (November 2000), p. 873.

[Expressing disbelief that some deny that human cloning produces an embryo]: "If it's not an embryo, what is it?"
- Jonathan Van Blerkom, human embryologist at University of Colorado, in American Medical News (Feb. 23, 1998), p. 32 (Dr. Van Blerkom said researchers' efforts to avoid the word "embryo" in this context are "self-serving").

"This experiment [producing Dolly] demonstrated that, when appropriately manipulated and placed in the correct environment, the genetic material of somatic cells can regain its full potential to direct embryonic, fetal, and subsequent development."
- National Institutes of Health, Background paper "Cloning: Present uses and Promises," Jan. 29, 1998, p. 3.

"The Commission began its discussions fully recognizing that any effort in humans to transfer a somatic cell nucleus into an enucleated egg involves the creation of an embryo, with the apparent potential to be implanted in utero and developed to term."
- Cloning Human Beings: Report and Recommendations of the National Bioethics Advisory Commission (Rockville, MD: June 1997), p. 3.

"Yet there is nothing synthetic about the cells used in cloning... The newly created embryo can only develop inside the womb of a woman in the same way that all embryos and fetuses develop. Cloned children will be full-fledged human beings, indistinguishable in biological terms from all other members of the species. Thus, the notion of a soulless clone has no basis in reality."
- Lee M. Silver, professor of molecular biology and evolutionary biology at Princeton University, in Remaking Eden: Cloning and Beyond in a Brave New World (Avon Books, 1997), p. 107.

[Listing research proposals that "should not be funded for the foreseeable future" because of "serious ethical concerns"]: "Such research includes: ... Studies designed to transplant embryonic or adult nuclei into an enucleated egg, including nuclear cloning, in order to duplicate a genome or to increase the number of embryos with the same genotype, with transfer."
- Final Report of the Human Embryo Research Panel, National Institutes of Health, Sept. 27, 1994, p. 12.

"One potential use for this technique would be to take cells -- skin cells, for example -- from a human patient who had a genetic disease... You take these and get them back to the beginning of their life by nuclear transfer into an oocyte to produce a new embryo. From that new embryo, you would be able to obtain relatively simple, undifferentiated cells, which would retain the ability to colonize the tissues of the patient."
- Ian Wilmut, in 7 Cambridge Quarterly of Healthcare Ethics 138 (Spring 1988).

[On being asked in an interview: "Do you think that society should allow cloning of human embryos because of the great promise of medical benefit?"]: "Yes. Cloning at the embryo stage -- to achieve cell dedifferentiation -- could provide benefits that are wide ranging..."
- Keith Campbell, head of embryology at PPL Therapeutics and co-author of Dr. Wilmut's landmark paper, in 7 Cambridge Quarterly of Healthcare Ethics 139 (Spring 1988).