Cloning: Nuts 'n bolts

Reproductive cloning

Therapeutic cloning

Dolly's disaster

Charting the debate

This cloned human embryo set off a volcano of public response when it was made last November. It only grew to six cells before dying.
Advanced Cell Technology.

It's permissible to make a human embryo in the laboratory if it's made by fertilizing an egg with sperm for implantation into a woman's womb. What if the embryo is made another way?

What if the embryo is used for research or therapy rather than reproduction?

Does a multicellular ball of tissue -- an embryo -- have the same rights and status as a human being?

Is it ethical to create an embryonic copy of John Doe to supply cells to keep John alive?

Is it right to use cloning to create an entirely new human being?

The process of human therapeutic cloning, a
theoretic method for making spare body parts.
Advanced Cell Technology.

On Friday, a National Academy of Sciences panel supported research into cloning to treat disease, but opposed reproductive cloning. Pres. Bush and others firmly support a total ban on cloning.

Reproductive technologies have a way of pushing the ethical envelope like no other field of medicine. In 1979, Louise Brown, the first "test-tube" baby (she was conceived in a dish, using in-vitro fertilization, or IVF), created an ethical conundrum.

The ability to fertilize eggs in a dish raised contentious issues about surrogate parenting, ownership and stewardship of embryos, and the ethics of doing research on human embryos.

But in hindsight, IVF seems pretty tame, and it's used thousands of times annually to help infertile couples have children. Few say IVF is unethical, or bad for parents or children.

In march the curative clones
In the past few years, a tricky new factor has entered the equation: Beyond making new people, lab-built embryos may help restore health to those already born. This miracle is the promise -- although not yet the reality -- of embryonic stem cells, cells that arise in embryos a few days after fertilization that can form any body cell.

Now, most embryonic stem cells come from surplus embryos made available by IVF clinics after the donor parents stop infertility treatments. But if used for therapy, these cells might trigger an immune response in a recipient. That should not happen with cells derived from clones of a patient, which would match the patients genes perfectly.

Nuclear transfer, or cloning, may provide a source of stem cells. Theoretically, it's possible to sidestep the problematic cloning by growing embryonic stem cells from the adult cells, but that's never been done.
Roslin Institute.

Embryonic stem cells could also be fruitful source of transplants for thousands of people who die awaiting transplants each year.

(Confused? Read our one-page guide to advantage and disadvantages of stem-cells and cloning.)

Faced with increased interest in human cloning for therapy, social conservatives have mounted a drive to oppose all human cloning. The Senate is about to consider a ban (already approved by the House of Representatives) that is based on the idea that human life starts at conception.

To many opponents, human cloning is the moral equivalent of Nazi eugenics. Writes Sen. Sam Brownback, author of the Senate bill, "Efforts to create human beings by cloning mark a new and decisive step toward turning human reproduction into a manufacturing process in which children are made in laboratories to preordained specifications."

But is creating embryos the same as creating babies? And if we fear and loathe reproductive cloning, should we also ban therapeutic cloning?

Terry Devitt, editor; Pamela Jackson, project assistant; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive.

©2002, University of Wisconsin, Board of Regents.