Dolly's anniversary--Is human cloning still a realistic fear?

I missed the 10-year anniversary of Dolly-the-sheep's birth last week (on the 21st of February). Maybe you did, too. Wonder what happened to the supposed cloned babies born to the alien-spawned wierdos?

Anyway, cloning--we learn in a free article from Nature online--"is beginning to change tact."

But as the decade passed and a menagerie of other mammals was cloned , no cloned human babies appeared. What did occur, and what moved the ethical debate in an unforeseen direction, was the isolation of human embryonic stem-cell lines by James Thomson and his colleagues at the University of Wisconsin, Madison.

With that achievement, it became clear that broad research avenues could be opened up by cloning human embryos to extract stem cells from them. These could then be used as disease models and drug targets, or to develop therapies involving tissue transplantation.

But as quickly as scientists recognized the potential of such opportunities, political and ethical opponents seized on the notion that allowing cloning in research would only ensure that it would one day be used for reproductive purposes. What's more, they argued, research cloning was a fundamental assault on human dignity, because it creates, manipulates and destroys human embryos for scientific ends.

"What really took place is that the stem-cell debate replaced the cloning debate," says Caplan. "Because there was — and is — a tremendous interest in trying to clone embryos, not people."

In spite of the South Korean scandal, where fradulent claims of cloned human embryos caused considerable concern, reproductive cloning still is the center of hopes for embryonic stem cell research. The research, most of it taking place with private money because of bush's halting of the production of new stem cell lines with federal money, continues. Meanwhile, according to Nature,

. . . opposition to cloning babies has remained firm through a decade of polling, at about 90%, but polls in recent years have shown that 60–70% of the public supports research using stem cells obtained from discarded embryos in fertility clinics.

"As people learn about the possibilities for new approaches to disease, they see the embryonic stem-cell issue in a different framework," says Jonathan Moreno, a bioethicist at the University of Pennsylvania, who co-chaired a committee that crafted 2005 research guidelines for the US National Academies. "They see it as medical research that could help them or their families."

The notion of cloning embryos to be a source of stem cells — as opposed to using embryos left over from fertility treatment that are slated for destruction anyway — is much more controversial. It remains a touchy political issue in many countries, including the United States, and is approached gingerly by public and private funders alike.

In the near term, "I rather doubt that we will see very much [cloning] in the context of embryonic stem-cell research in the United States", says Moreno. But he thinks advances are likely to come in countries where the work is seen as more acceptable, such as Britain, where groups led by Wilmut at the University of Edinburgh and Alison Murdoch at the International Centre for Life in Newcastle upon Tyne have been given permission to pursue it. (Murdoch's group has already cloned at least one human embryo, but has had no luck extracting stem-cell lines.)

The research, and the interest, goes on. If you wonder what animals have been cloned--famous and not--check out the excellent cloning timeline in the Nature article, with photographs of cloned animals. 

Marie Godfrey, PhD




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