What Is Cloning?

BBC

Earlier this year, scientists in South Korea announced they had cloned thirty human embryos. They insist though that they don't intend to create thirty identical babies, instead they want to use stem cells from the embryos to treat diseases.

In this most controversial area of scientific research, do you understand the difference between reproductive and therapeutic cloning? How far are scientists from cloning humans -- is the intention really there to create exact human replicas and what are the ethical concerns? This week's Big Question is: What is cloning?

Emma Joseph is joined by bioethicist and lawyer, Arlene Judith Klotzko who has written A Clone of Your Own and Azim Surani, Professor of Physiology and Reproduction at Cambridge University and a specialist in stem cell research.

So what is cloning? The Human Genetics Advisory Commission in the UK has defined cloning as "producing a cell or organism with the same nuclear genome as another cell or organism".

How does cloning work? The most successful method at the moment is what is called nuclear transfer. An egg cell (A) has its nucleus removed and the nucleus of another cell (B), (any cell from any human) is inserted into the egg. The egg (A) grows but has the nucleus of B - along with all B's genetic material. The clone will carry all B's genetic information.

Has cloning been successful? Dolly the Sheep is arguably the most famous clone - the first successful mammal clone from an ordinary adult cell. But she wasn't the first successful clone. In 1938 a German scientist, Hans Spemann, argued that in theory animals could be copied by fusing an embryo with an egg cell. In 1970, a British molecular biologist, John B. Gurdon, managed to insert cells from a frog embryo into a frog's egg. The eggs did develop into tadpoles, but didn't last long. In fact, the history of cloning streches back to 1885.

Over the past five years, various doctors and scientists, including American Richard Seed and Italian Severino Antinori have stated they were attempting to clone a human being.

Some people are unhappy with the ethical implications of human cloning - they believe it is tampering with the very essence of life. But some scientists think reliable cloning will turn out to be impossible.

This edition of The Big Question was first broadcast on 15th May 2004

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