The South Korean scientists who successfully extracted stem cells from cloned human embryos are now facing questions over the origin of the 247 donated eggs used in their experiments. The Seoul National University team, which published its breakthrough in the journal Science earlier this year, created 30 cloned human embryos. The researchers extracted stem cells from 20 of these, from which they managed to grow one human embryo stem cell (ES cell) line. But, according to a news report published in Nature, team leader Woo Suk Hwang is now under pressure to reveal more details about how he recruited egg donors for the project.
SCNT (somatic cell nuclear transfer), the 'cloning' technology used to create Dolly the sheep, involves replacing the genetic material of an unfertilised egg cell with that of another adult body cell. Scientists hope to use this approach to grow cloned human embryo stem cells, which could potentially produce genetically identical cell therapies for a range of incurable diseases.
The South Korean team, lead by Drs Woo Suk Hwang and Shin Yong Moon, carried out their work using 247 unfertilised eggs donated by 16 women. The researchers needed a large number of donated eggs, since the SCNT procedure is very inefficient. Jose Cibelli, a study co-author, is surprised that so many women were willing to donate eggs for the project. 'It's a painful procedure and there is risk involved', he told Nature, adding that 'it would never fly in the United States'. The Nature report says that PhD student Ja Min Koo originally said that the donors had included herself and another woman who worked in Hwang's laboratory. But the journal claims that she later called back, to say she had not donated eggs, 'blaming her poor English for a misunderstanding'.
Hwang flatly denies the findings. 'Nature's claim is totally groundless', he told the Korea Times, adding: 'I swear none of my students donated eggs for the research. For some reason, the journal is trying to undermine our study'.
Meanwhile, the UK's Human Fertilisation and Embryology (HFEA) has received its first application from scientists wanting to clone human embryos for medical research. A team at the Institute of Human Genetics in Newcastle has requested a licence to carry out therapeutic cloning research, in particular to develop new diabetes treatments. Team leader Alison Murdoch said last week that she would ask women attending IVF clinics to donate spare eggs for the project if, as expected, it is approved by the HFEA. The news follows the recent announcement by Ian Wilmut, who helped create Dolly the sheep, that he plans to apply for a licence to carry out therapeutic cloning for motor neurone disease research.