South Korean stem cell pioneer resigns

Woo Suk Hwang - head of the South Korean team that obtained the world's first embryonic stem cells (ES cells) from cloned human embryos - has quit his public positions after admitting that some eggs used in the work were provided by junior researchers and paid donors. The shock resignation follows a statement last week by US scientist Gerald Schatten, in which he ended his 20 month collaboration with Hwang over the allegations.

In a press conference given on 24 November, Hwang announced his resignation from all his official positions, including chair of the recently launched World Stem Cell Hub. 'I sincerely apologise for having stirred concern at home and abroad', he told reporters. He said that he had found out late last year that two female team members had donated eggs for his team's ground-breaking research, which was published in the journal Science early in 2004. But Hwang chose not to make this information public: 'After serious consideration, I finally chose to protect my researcher's privacy. I could have been wiser', he admitted. Hwang also said that the head of a hospital who supplied eggs for the project told him last month that some donors had been paid, despite the fact that the Science article had said no women were paid to donate eggs.

The journal Nature first raised concerns over the origin of the 247 eggs used in the research in May 2004. It claimed that PhD student Ja Min Koo originally said that the donors had included herself and another woman who worked in Hwang's laboratory. However, the journal also stated that she later called back, to say she had not donated eggs, 'blaming her poor English for a misunderstanding'.

The issue resurfaced following a police investigation of Hwang's collaborator Sung-il Roh, a fertility specialist at MizMedi Hospital in Seoul. It emerged that Roh paid some women 1.5 million won (around £840) to donate eggs to the project, which he said was compensation for the inconvenience of being hospitalised and having hormone injections for the 15-day long procedure. Although paying women to donate eggs has been outlawed in South Korea since the beginning of this year, it was still legal at the time the donations were made.

Last Tuesday, the Seoul-based television channel MBC revealed that at least one of Hwang's researchers had donated eggs for the work. In an interview with MBC, Hwang said that junior scientists had asked him about donating eggs to the project, and that he was 'very moved' by the offers. But he added that to avoid misunderstandings, he persuaded them 'on several occasions' that it would be better to work with the eggs the team had, even if there weren't enough. It now appears that the women donated their eggs without his permission, using false names.

Hwang says he has resigned from all his public posts as a way of seeking 'repentance', but will continue with his work at Seoul National University. 'Being too focused on scientific development, I may not have seen all the ethical issues related to my research', he said. UK researchers have said the episode highlights the need for strong regulatory oversight of the field, as provided by the Human Fertilisation and Embryology Authority. Biologist Robin-Lovell Badge, of the National Institute for Medical Research said: 'the excellent research carried out by Hwang and his team must continue, but in a way that considers the ethics in an appropriate way'.