Schatten in the spotlight
Do our only cloned primates come from the lab of Woo Suk Hwang's colleague?
During the height of his friendship with Woo Suk Hwang, Gerald Schatten took to calling the South Korean scientist his brother. Now, with Hwang's international disgrace sealed and that friendship dissolved, the scientific community has questions for the US researcher.
Schatten is arguably one of the top achievers in cloning work with primates, thanks to research he collaborated on with Hwang and others.
He may also benefit from patent applications on cloning techniques behind the work; both Schatten and Hwang have filed patent applications, although Hwang's claims may be rejected given that the data supporting them are fraudulent.
Schatten, a 56-year-old developmental biologist, directs a research institute affiliated with the University of Pittsburgh School of Medicine in Pennsylvania. He has spent much of his scientific career trying to clone monkeys, to improve animal models of disease and inform studies of human stem-cell research.
But Schatten and others have had an extremely difficult time making such cloning work. In a 2003 study published in Science1, the normally ebullient Schatten was so discouraged that he even speculated that reproductive cloning of monkeys would be impossible.
Less than a year later, however, good news from South Korea gave Schatten fresh hope. In a now infamous Science paper from February 2004, Hwang reported that he had cloned a human embryo and derived stem cells from it2. If it was possible in people, perhaps it was possible in their primate cousins. Schatten and Hwang started working together, and Hwang began sending researchers and technicians to Schatten's lab.
A step forwards
The collaboration paid off for Schatten in December 2004, when he and Hwang reported that they had cloned a handful of monkey embryos from adult monkey skin cells (see ' Biologists come close to cloning primates') . No live monkey clones were born, but the work was a huge step nonetheless3.
No one has raised explicit questions about the work yet, but given that Hwang is listed as a co-author some say it should be scrutinized. Schatten "has to explain his role in this paper", says developmental biologist Rudolf Jaenisch at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts. It is unclear, for example, whether the work was done entirely in the United States or in part in South Korea. "It would be the only successful cloning of primates, if it's true," he adds. "It needs to be investigated."
Two co-authors of the paper, Duane Compton and Tanja Dominko, told Nature they had received no indication from Schatten that anything in the piece was questionable. Schatten declined an interview request from Nature.
Proof of method?
Schatten has said the monkey paper was partly a validation of Hwang's method of transferring cell nuclei. He crowed about the Korean team's contribution to his methodology in public: "We could have been struggling for decades. Now our work is taking off fabulously. I think the whole world owes the Republic of Korea a debt of gratitude," Schatten told a reporter from the Associated Press last April.
Now, scientists are keen to check if Hwang's methods work at all; in part by taking a hard look at the monkey studies. "It seems like a logical place to go to see whether there's any validity to the technique itself," says Kevin Eggan, a developmental biologist at Harvard University.
In the meantime an investigation continues at Schatten's university. "We are in the process of reviewing everything involving the Koreans' work and the University of Pittsburgh's investigatory panel is still deliberating. I don't anticipate an official statement coming from the university before the investigatory panel makes its report," wrote Jane Duffield, director of the medical school's press office, in an email to Nature on 6 January.
Show me the money
The results of these investigations may also have some bearing on patent applications. Both Hwang and Schatten have patents pending on cloning techniques, neither of which name the other as a co-inventor.
Hwang filed an application in Korea in 2003, describing the innovations that he says allowed him to produce a stem-cell line from a cloned human embryo. It follows the structure of his discredited 2004 paper in Science.
Schatten's application, filed in the United States in April 2004, is based on his monkey work, and identifies a method of overcoming a problem he says is encountered with transfer of cell nuclei in primates. It also covers a range of possible uses, including therapies developed from stem cells produced using particular techniques.
It is not clear how these claims will pan out. Both are based at least in part on previously established methods, says Margaret Sampson, a patent attorney at Vinson & Elkins in Austin, Texas. And other groups have applied for patents on cloning technologies. "Neither Schatten nor Hwang will probably be the undisputed holders of all rights to the technology. It's more likely that different groups will hold patents on different methods of making and using stem cells," she says.
Whoever does end up with the patents might stand with a lot to gain.
- Simerly C., et al. Science, 300. 297 (2003).
- Hwang W. S., et al. Science, 303. 1669 (2004).
- Simerly C., et al. Dev. Biol. , 276. 237 - 252 (2004).