In a new paper, a team of some 20 researchers says that they were unable to replicate a proposed alternative to the CRISPR/Cas9 gene editing approach, Nature News reports.
Earlier this year, researchers led by Hebei University of Science and Technology's Chunyu Han reported in Nature Biotechnology that they'd found that the Natronobacterium gregoryi Argonaute, also known as NgAgo, could be used as a genome-editing endonuclease and could replace Cas9.
Doubts about this approach, though, have been swirling for months, according to Retraction Watch. In July, GenomeWeb reported that a number of researchers had been having difficulties reproducing the work. GenomeWeb's Andrew Han noted that researchers in a number of internet forums said they were unsuccessful or were seeking ideas as to how they might've gone wrong. A few researchers, Han noted, reported success. One, researcher, Australian National University's Gaetan Burgio, initially reported encouraging results, but later wrote in a pair of blog posts that it did not actually work. Then in August, Nature News noted that another group abandoned its NgAgo efforts and a survey of researchers found that 97 percent thought the approach didn't work. Nature Biotechnology is also conducting an investigation.
Now, in Protein & Cell, researchers from the US and China wrote that they tested the approach in a variety of cells and organisms. They tried it in eight different laboratories using materials supplied by the original researcher, Nature News adds, but with no success.
"We therefore urge the authors of the original paper to clarify the uncertainty surrounding NgAgo and provide all the necessary details for replicating the initial, very important results," the team wrote in Protein & Cell.
Another group reported in Cell Research that they suspected that NgAgo might only block, not edit, genes, Nature News notes.
It adds that Chunyu Han is standing by his work.