Or, the alleged DNA inaccuracy could be the tip of something more sinister.Hwang’s bosses at Seoul National University – prodded by 30 skeptical faculty members – have launched an investigation. Several of the samples appear to be identical – suggesting more than one came from a single person.If the critics are correct, the DNA data could simply be yet another careless reporting error akin to a photography mix up the Hwang team disclosed to Science last week. That’s because each cloned embryo was required to have a separate DNA sample showing it was derived from a unique individual. ![]() He has publicly apologized for the ethical lapses and quit as head of the World Stem Cell Hub, an international project he had launched in October that envisioned California and British labs in addition to a facility in Korea.At the time, Hwang defended his work as scientifically sound.But doubts about his central claim – that he extracted separate stem cell colonies from 11 patients from cloned human embryos – are growing.Colleagues in South Korea are also demanding independent confirmation of Hwang’s results, and Hwang has been in and out of the Seoul National University hospital since last week, suffering from “extreme stress,” hospital officials said.The critics allege that Hwang’s assertion, published by Science, that he created 11 separate cloned embryos may be inaccurate. The implanted DNA then drives the egg to develop into an embryo.Hwang is considered a national hero in South Korea for his cloning prowess. The basic idea of cloning is to take a patient’s genetic material and inject it into an unfertilized human egg. It’s not good,” said Rudolf Jaenisch, a leading stem cell scientist at the Whitehead Institute for Biomedical Research in Cambridge, Mass.Many stem cell scientists had stood by Hwang’s work even as the South Korean admitted to ethical lapses and minor data reporting errors.Now, a significant number, such as Jaenisch, are calling on Hwang to submit his cloning research to independent analysts to bolster public confidence, which they perceive as eroding because of the continued controversy over Hwang’s work.Schatten set off the ethics furor last month when he publicly accused Hwang of collecting eggs from subordinate scientists, a practice many consider unethical, and lying about it to him.But until now, even Schatten has maintained that the main findings of the paper – that tailor-made stem cells were extracted from embryos cloned from the DNA of sick volunteers – were valid.The University of Pittsburgh declined comment and said Schatten would be unavailable to discuss what prompted him to demand his name be removed from the cloning paper.The journal Science acknowledged receiving Schatten’s demand, but spokeswoman Ginger Pinholster declined to release Schatten’s letter because “it contains unsubstantiated allegations.”Schatten’s name was listed last among the 25 authors, signifying that he was the senior researcher on the project.”No single author, having declared at the time of submission his full and complete confidence in the contents of the paper, can retract his name unilaterally, after publication” the journal said in a statement.The journal has said he has no reason to believe Hwang’s primary finding “is any way fraudulent or questionable.”Stem cell scientists hope to clone embryos to extract stem cells in order to better learn how diseases develop and even perhaps rejuvenate failing organs. ![]() SAN FRANCISCO – The validity of Hwang Woo-suk’s pioneering human cloning work in South Korea is in question as a former collaborator tries to distance himself from the groundbreaking research.University of Pittsburgh researcher Gerald Schatten has demanded that the journal Science remove him as the senior author of report it published in June to international acclaim that detailed how individual stem cell colonies were created for 11 patients through cloning.Schatten’s highly unusual demand, in a letter that Science confirmed receiving Tuesday, adds to growing skepticism over Hwang’s findings and places the entire cloning and stem cell field under a cloud.”It’s a very serious step.
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