Monday, November 26, 2001

Cloned Human Embryo

It seems that the human embryos have been cloned for the first time. Just as when scientists cloned Dolly the sheep, a single adult cell was fused with a nuclear-derived egg and tricked into behaving like a newly fertilized embryo. If this is implanted into the uterus, a child would be born, and that is, in essence, a clone. Therefore, scientific technology has brought mankind to the brink of producing a human clone. Although the purpose of this experiment is said to be the development of a way of obtaining embryonic stem cells matched to patients for tissue engineering and transplantation medicine, what is concerning is that, once technology develops, there are many instances when it is used for an entirely different purpose than originally planned.

Researchers from Advanced Cell Technology in the United States used somatic cell nuclear transfer in which the nuclear DNA in an egg is replaced from an adult cell and then fused to form pre-implantation embyos. Of the 19 eggs used, three went on to develop to the six-cell stage. According to the evening edition of the Asahi Shimbun, in a separate experiment, researchers used a technique in which an egg cell is activated without being fertilized by a sperm cell. A special chemical was added to 22 egg cells and six of them reprogrammed themselves to develop blastocoele cavities. That means the embryo had developed an inner and outer group of cells--the inner cells being the potential source of embryonic stem cells. This technique is called "parthogenesis."

In the Seicho-No-Ie Japanese magazine Hikarino Izumi (Fountain of Light), I have already expressed my opposition regarding fertilized eggs produced from the union of egg and sperm for use in creating stem cells and other purposes. However, the cloned embryo in this case is not created from a fertilized egg that would eventually develop into a fetus. The egg cells are, of course, "alive", but they are, if left unfertilized, destined to die. It's difficult to say, then, that using this for medical purposes is entirely unethical. On the other hand, however, if cloned embryo created through techniques such as this are transplanted into a uterus and the process of creating humans is established, the cloned embryo would be extremely similar to "normal" fertilized egg or embryo. To use this as a means to create human organs, I think, brings forth some ethical questions. In other words, at this point, it's still unclear as to how to determine the ethics of embryo cloning. That's why the "Human Cloning Law" created by the Japanese government this summer does not prohibit to create a cloned human embryo itself.

According to news reports, successful cloning of human embryo have been reported in Korea in 1998 and in China last year, but no details have been disclosed. This is the first time that the "know-how" has been announced. If, from this announcement, the cloning of embryo is facilitated, the use of stem cells and human cloning may become easier as well. In this sense, I think there is an urgent need to expedite the establishment of a worldwide moral/ethical standard for this field.

- MT

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