Kyoto University Prof. Shinya Yamanaka, the creator of induced pluripotent stem cells and a 2012 Nobel laureate, has denied allegations that he manipulated images in a research paper he published in a European journal in 2000.
“There were no cut-and-paste images, and the content of the article is correct,” Yamanaka told a news conference on Monday.
The 2000 article in EMBO Journal dealt with mouse embryonic stem cells and had no direct link with Yamanaka’s groundbreaking 2006 paper on the iPS cells he created.
Yamanaka nevertheless apologized for failing to preserve the laboratory notebooks of the 2000 paper’s co-authors.
“I’m really sorry for this thing happening at a time when trust in Japanese scientists is being shaken,” he said.
The scientist’s comments come amid the recent controversy over the credibility of “STAP cells,” a new type of stem cell claimed to have been discovered by Haruko Obokata, a researcher at the state-affiliated Riken institute accused of manipulating images and committing other mistakes in two papers published to announce the discovery. STAP stands for stimulus-triggered acquisition of pluripotency.
Kyoto University’s Center for iPS Cell Research and Application, headed by Yamanaka, has investigated the image manipulation allegations concerning the 2000 article. These were first posted on the Internet in April 2013.
According to the center, the method adopted to create the mouse ES cells continues to be used. Based on Yamanaka’s laboratory notebooks, the center confirmed that the experiments for the 2000 article were conducted in or around 1998.
At the university, however, the center could not find the other researchers’ notebooks or the raw data from the experiments. It was also unable to reach a Chinese researcher who played a key role with Yamanaka in the research.