Global cloning project imperiled

SAN FRANCISCO -- The work of the world's foremost human cloning researcher, Hwang Woo-suk, has been thrown under an ethical cloud, jeopardizing an international cloning project that he and several prominent US researchers had announced last month.

The World Stem Cell Hub foundation had announced plans to open cloning centers in San Francisco and London, but US support for the effort waned after Hwang was accused of obtaining egg donations from a subordinate and of misleading a US collaborator about the matter.

Pacific Fertility Clinic, which had said it would help the stem cell hub collect eggs beginning in January, said Monday that it has severed all ties with Hwang and that it has dropped all involvement with cloning research.

Scott Kaplan, a spokesman for the clinic, based in San Francisco, declined further comment.

The Harvard University Stem Cell Institute has put on hold a possible collaboration with the Korean team pending more information. And the nonprofit Children's Neurobiological Solutions Foundation, based in Santa Barbara, Calif., said it was delaying a grant application from the Korean-led stem cell hub.

''These are very serious claims being made," said Shane Smith, science director of the nonprofit group, which seeks treatments for childhood brain disorders. Smith declined to give the amount of the grant request, but said it exceeded the small nonprofit's usual maximum of $75,000.

A researcher at the University of Pittsburgh, Gerald Schatten, said Saturday that he had resigned from the stem cell hub and had ended his 20-month collaboration with Hwang because of the South Korean's ''unethical practices." Schatten released a statement on Saturday announcing his resignation from the stem cell hub and has declined further comment.

Last year, Hwang's team at Seoul National University became the first to successfully clone a human embryo.

Since then, though, rumors have swirled that some of the 242 eggs used in the experiment had been donated by subordinate scientists in Hwang's cloning lab. Scientists and ethicists said collecting eggs from an employee is unethical because of the potential for subordinates to feel coerced.

Hwang has denied those accusations; he again defended his research on Monday in Seoul.

''All research up until now has been conducted in strict observance of the government-set guidelines," Hwang said, according to South Korea's Yonhap news agency. He did not elaborate.

No human cloning projects are known to be taking place in the United States, although Harvard University researchers have asked school officials for permission, and the $3 billion California Institute for Regenerative Medicine has said it would fund such work.

Gareth Cook of the Globe staff contributed to this report.