WIKIMEDIA, MAGGIE BARTLETT, NHGRIWhen Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe, Japan, and her colleagues first published their new method of reprogramming cells, known as stimulus-induced acquisition of pluripotency (STAP), they claimed to have created multiple stem-cell lines from different mouse strains, although only the data on cell lines derived from the 129B6F1 strain were published in their Nature papers. A new genetic analysis provides evidence that some cell lines that were created but not published were actually derived from different mouse strains than claimed, suggesting that laboratory contamination may be at play, Nature News reported last week (March 27).
The analysis was conducted by a collaborator on the original papers with Obokata, Teruhiko Wakayama of Yamanashi University, Japan. Wakayama first admitted to having difficulty reproducing the results as questions surrounding the technique began to arise six weeks ago. He held a press conference on March 10 requesting that the studies be retracted because of lingering confusion. The new analysis—which Wakayama conducted on two lines that Obokata had supposedly derived from the 129 mouse line prior to publication, but the results of which are not included in the papers—showed that two lines did not genetically match the 129 mouse strain, instead appearing to have come from the B6 strain and the 129B6F1 strain, according to Wakayama. “This discovery was a shock,” he told Nature News, although he added that “this result does not call into question the Nature papers.” Indeed, Wakayama also tested the STAP cells described in the paper and found that they did match the claimed 129B6F1 strain.
“Something is grossly wrong,” stem-cell researcher Hiromitsu Nakauchi of the University of Tokyo added.
Obokata did not respond to Nature News about the analysis. Wakayama said that he has also shared 20 STAP cell lines with an independent institution for further investigation.