Ian Wilmut, who oversaw the creation of Dolly the sheep, the world's first cloned mammal, was granted a license yesterday by British regulators to create cloned human embryos for research.
It is the second such license granted by the British government in the past six months and parallels similar recent government actions in Korea and China -- a trend that has some American scientists concerned that the United States is losing its lead in one of the fastest-paced specialties in biomedical research.
Ian Wilmut focuses on Lou Gehrig's disease.
It is illegal to create cloned human embryos with federal money in the United States. A few U.S. scientists have recently said they intend to do so with private money, and California voters recently passed a measure to finance human embryo cloning and related research with state grants. But congressional conservatives, bolstered by recent election gains, are gearing up for a renewed attempt to ban such experiments, casting a chill on the field domestically.
Wilmut, of the Roslin Institute in Scotland, emphasized that his team will destroy the cloned embryos within 14 days of their creation and that none will be allowed to grow into a fetus. The goal, he said, is to grow the embryos as sources of stem cells, which may hold key secrets about the underpinnings of various diseases.
"Once the stem cells are removed for cell culture, the remaining cells will be destroyed," Wilmut said in a prepared statement. "The embryonic stem cells that we derive in this way will only be used for research into motor neuron disease," specifically amyotrophic lateral sclerosis, or Lou Gehrig's disease.
The plan is to make embryos that are clones, or genetic replicas, of patients with a family history of Lou Gehrig's -- a disease whose genetic roots remain largely unknown. Those embryos will be made by taking a single cell from a patient -- such as a skin cell -- and fusing it with a human egg whose own DNA has been removed. When stimulated with electricity or chemicals, the fused cells grow into an embryo genetically identical to the patient.
Once extracted from those embryos, the stem cells will be treated in a way that forces them to mature into motor neurons -- the kind of nerves that connect the brain and spinal cord to muscles and that mysteriously degenerate in Lou Gehrig's patients.
The experiments will allow the team to watch the ill-fated neurons develop and make connections with others in laboratory dishes, providing an unprecedented view of a disease unfolding at its earliest stages. Wilmut and his colleagues -- Paul de Sousa of Roslin and Christopher Shaw of Kings College in London -- also intend to test various experimental drugs on the cultured neurons to get a quick sense of which ones may be worth pursuing in human studies.
Experiments involving embryos are regulated in the United Kingdom by a government body called the Human Fertilization and Embryo Authority. It granted its first license to clone human embryos in August, giving the green light to Alison Murdoch of the University of Newcastle. As of late last year, that team had not succeeded in creating a living colony of stem cells from cloned embryos.
Murdoch and Wilmut are restricted by the terms of their licenses to using poor-quality eggs that were not fertilized during infertility treatments -- a compromise the government imposed to address ethical concerns about the use of healthy human eggs in experiments.
In 2004, researchers in South Korea became the first to derive stem cells from a cloned human embryo, and teams in China have reported similar successes.
News of the licensure decision in England triggered polarized responses in the United States.
"Bravo for the British," said Robert Lanza, vice president for medical and scientific development at Advanced Cell Technology, a company based in Worcester, Mass, that pursues stem cell therapies. "It's nice to know some countries are keeping religion and science separate."
Richard Doerflinger, director of abortion-opposition activities for the U.S. Conference of Catholic Bishops, saw things differently.
"Biologically these embryos will be the twin brothers or sisters of current patients and will be created only to be destroyed for research," he said. "You're deliberately bringing developing humans into the world with the disease so you can harvest their cells and study them."
Wilmut said he was optimistic that the experiments would lead to therapies for the incurable disease, but he also warned against hyping the stem cell approach.
"We believe we can give hope," he said in an interview, "but new treatments will be a number of years away."