Biotechnology and Ethics: Human Cloning
Part Two
Let’s talk about one of the main reasons for the opposition to cloning, physical risks.
When Dolly the sheep was cloned in 1997, 277 embryos were produced, and 29 were implanted into recipient ewes. Only one produced a live lamb. In other attempts lambs died soon after birth or had significant physical abnormalities.
The cloning of Dolly was experimental. With such dangers, experimentation on humans would be immoral.
In the United States efforts to ban cloning to produce a human child failed. Part of the reason had to do with limitations that would be placed on scientific advancement. A ban might also have precluded cloning to produce human embryos for research and medical purposes.
In the United States Congress, some representatives favored banning all human cloning while others wanted a more limited bill, one that would only ban cloning to produce a child.
The United States government has not passed any ban on cloning to produce children. Other countries have, including Germany and the United Kingdom.
In the UK, using cloned embryos, up to 14 days old, is permitted.
Please read Chapter Four of the report, Scientific Background. On p. 60 of that chapter, the basic steps in cloning are explained:
1. Obtain an egg cell from a female of a mammalian species.
2. Remove the nuclear DNA from the egg cell, to produce an enucleated egg.
3. Insert the nucleus of a donor adult cell into the enucleated egg, to produce a reconstructed egg.
4. Activate the reconstructed egg with chemicals or electric current, to stimulate the reconstructed egg to commence cell division.
5. Sustain development of the cloned embryo to a suitable stage in vitro, and then transfer the resulting cloned embryo to the uterus of a female host that has been suitably prepared to receive it.
6. Bring to live birth a cloned animal that is genetically virtually identical (except for the mitochondrial DNA) to the animal that donated the adult cell nucleus.
The section in Chapter Four entitled “Stem Cells and Regenerative Medicine” (pp. 65 – 68) is instructive. It underscores the importance of cloning in stem cell research.
A central problem in regenerative medicine is to overcome the problem of rejection.
If the stem cells or other cells used for transplantation are derived from an embryo cloned from the patient, then rejection should not be a problem.
This is one of the central reasons to value human cloning, but it is not done with the prospect of producing a child. Many hope that the cloned embryo would be destroyed within a few days. This is thought to minimize problems from those who object to destruction of the embryo..
All the moral objections to using embryos in research apply to cloned embryos.