Ethical Reflection on Scientific Advances
Bishop Elio Sgreccia
President, Pontifical Academy for Life

Looking at 'cybrids', human-animal hybrids

In all likelihood, the whirl of sensational statements and polemics which has exploded in the media the past few days will probably die down to give way to other announcements, more or less filled with emotion and apprehension, as happens in storms at the end of the season when we go back to work after the squall has passed, hoping against hope that there has been no damage.

Nevertheless, we think it may be useful to return briefly to the Human Fertilisation and Embryology Authority's statement, published this past 5 September, in order to better grasp and clarify the facts and to explain the reasoning of those who claim it is impossible to approve the opening of an illegal process today in the hope of some "longed-for" advantages tomorrow.

First of all, what has the Authority authorized?

This is the body which, subsequent to the famous 1984 Warnock Report, the Government of the United Kingdom made responsible for the task of regulating the in-vitro fertilization of human beings in Britain and which has since been responsible for supervising this delicate matter.

The authorization granted on 5 September, with the assent of the new Government of the United Kingdom, concerns biological research using hybrid embryos (animal-human) subject to certain conditions: the presentation of research projects depends on prior recognition that such an area of research can, with caution and careful scrutiny, be permitted.

It is difficult to comprehend the vagueness of this condition; in any case, it seems there is a desire to make it clear that the authorization is not an unconditional "green light" but continues to depend on demonstrating that a research project is both necessary and desirable and meets the overall standards required.

Therefore, also in the context of authorization, the ultimate condition remains the approval of specific projects that comply with the regulations.

Yet, it is quite obvious that this is a question of authorization, of authorizing the creation of human-animal hybrids, known as cybrids.

In the meantime, it seems to us to be more logical and precise, as regards the information disseminated, to speak of hybrids rather than chimeras.

Hybrids: interspecies fertilization

Hybrids are the result of fertilization that derives from the two genetic patrimonies of two individuals of a different species, such as occurs in nature when a mule is foaled by a mare and a male ass; whereas the chimera is the result of the fusion or mixture of two previously developed embryos of different species.

In our case, it is a question of fertilization, artificial fertilization, with recourse to the same technique as that used for cloning: the combining of an animal ovum (ovine or bovine) with the nucleus of a human somatic cell: the mitochondrial DNA remains in the egg from which the nucleus has previously been removed, while the rest of the genes come from the human nucleus (99 percent of the genetic patrimony is human); the animal egg-cell also provides the cytoplasm that must stimulate and develop the nucleus.

The result of this union is not without "interspecies" implications, although it takes place in a laboratory: the genetic patrimony that comes from human corporeity recalls human dignity and the animal egg-cell refers to a somatic element of a different species.

Ultimately, this is a question of interspecies artificial fertilization using cloning techniques. In other words, it means using techniques that are not consonant with British law on human artificial procreation, promulgated earlier by the same Authority and which does not provide for the authorization of interspecies fertilization.

The use of the animal egg-cell is deemed necessary because this cloning-type procedure has a very low success rate (about five percent), hence, it would be impractical to approach thousands in order to remove egg-cells.

If artificial fertilization deprives human procreation of its dignity because of the absence of personal relations between husband and wife; if human cloning itself, relying on the genetic patrimony of a single parent, is marked by a further loss of humanity and dignity; then by getting rid of this additional barrier to the creation of hybrids for cloning, dehumanization touches the threshold of monstrosity and takes a further step down the slippery slope, as happens every time a fundamental ethical requirement is discarded.

Human-animal cloning: a failure

It should be added, as the same report of the Authority states, that this procedure has already been tested in various countries. Experiments have used the nucleus of a fecundating human cell and a cow or a rabbit oocyte from which the nucleus has previously been removed without the experimenters obtaining any significant success.

In 1999 there was a public announcement that hybrid human-bovine embryos had been produced years earlier by Robert P. Lanza, José C.V. Cibelli and Michael D. West of the Advanced Cell Technology Company in Massachusetts, U.S.A.; the experiment had taken place years earlier and does not seem to have been crowned with success.

In China in 2003, Y. Chen and his team proceeded to create human-rabbit hybrids. K.H. Chang, with his team at Seoul National University, South Korea, reported the creation of human-cow embryos in 2003. Lastly, in Cyprus in 2006, Panajiotis Zavos and his team created human-bovine embryos.

In all these experiments the percentage of successful fertilization was very low and the percentage of embryos that developed to the blastocyte stage was even lower; thus, the overall result was considered unsuccessful and continued to be regarded as a curious experiment.

Moreover, the scandal of the false results published by Dr. Hwang Woo-Suk in South Korea contributed to undermining the reputation of any type of cloning.

To conclude, it is impossible to understand why, despite such failure and discrediting, the Authority should once again be proposing this method as "necessary and desirable... both in scientific and ethical terms".

As a result, it would seem that the scientists' purpose is to obtain hybrid embryos from which to extract stem cells which, because of their quality, would not be rejected: it is known that human stem cells are subject to rejection when transferred to a diseased organ and are also liable to develop tumours.

It is now believed that by continuing to use embryonic stem cells from hybrid tissue, such drawbacks could be prevented.

However, we have said that hybridization has had no appreciable success. In almost all cases, in fact, the embryos turn out to be simply human and rarely contain traces of animal mitochondria) DNA.

Thus, one might think that other interests are pressing for this path to be taken: the desire to experiment on the embryo unscrupulously, free of prohibitions, obtaining consent on this case so that it may apply to all future cases; or the use of funds for research already allocated or obtainable, in the hope that they may be used in the future.

With regard to the ethic that the researchers of the Authority present, it can only be a utilitarian ethic which means that two offences have been made against the human and rational ethic based on human dignity: the goal has been envisaged without paying attention to the means (creation of embryos and their destruction); and an indisputable crime has been committed today with a view to gaining a hypothetical advantage tomorrow.

We still hope that in their dedication to this delicate field, scientists will have recourse to ethics based on the true dignity of the human being, which is also present in the very first stages of a human life.

Finally, it should be remembered by those who have at heart the treatment of degenerative diseases that they have access to the use of adult stem cells with good prospects of success.


Taken from:
L'Osservatore Romano
Weekly Edition in English
17 October 2007, page 10

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