Groundbreaking discovery: Skin cell DNA can be inserted into a human egg to develop an early-stage embryo.
A breakthrough in embryonic stem cell research that could lead to people receiving transplants based on their own tissues has been both hailed by scientists, but received a cautious response from ethicists, who have warned it again raises big questions about when life begins.
In a world first, a US team of scientists used a human skin cell to create a cloned human embryo from which they were able to extract embryonic stem cells.
Published in the journal Cell, the discovery involves a technique known as therapeutic cloning. Skin cell DNA was inserted it into a human egg that developed into an early-stage embryo, or blastocyst.
The scientists said the resulting stem cells had the potential to be turned into a variety of cell and tissue types for use in organ repair and transplants.
Dieter Egli, senior research fellow at the New York Stem Cell Foundation Research Institute, was among those who described it as a significant step.
He said that if embryonic stem cells could "be made from adults like us, that would mean we could make replacements for any type of cells we would need".
Nicholas Tonti-Filippini, Head of Bioethics at the John Paul II Institute for Marriage and Family, said it was far too early to conclude the research would lead to therapy, and opposed the creation of an embryo for it later to be destroyed.
"I don't support the destruction of human embryos and I think it is a very sad way for us to go in Australia," he said.
He said it was unnecessary because similar results were possible through the use of what are known as induced-pluripotent stem cells, which are not derived from embryos.
Monash University Human Research Ethics Committee chairman Ben Canny said the latest breakthrough was unlikely to change the debate, but would prompt a return to complex ethical questions about whether it was acceptable to destroy a life to save a life.
"An ethical minefield has not opened up, it has been there for many years," he said. "It goes back to when the first cloning of Dolly the sheep was done in the 1990s."
Professor Canny said his view was that the ability to clone human embryos was an important therapeutic development. As long as the ethical questions were broadly debated in society and carefully regulated, then the benefits would outweigh the concerns.
"I have no problem with the way it's regulated now," he said. "There are several levels of committees and important safeguards to make sure that the people who donate these materials are fully aware of how they will be used."
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