Deleted Scenes: Arsenic-based life gets even more toxic

Scientists pound two more nails into the coffin of an incredible scientific claim

Web edition : 5:53 pm

The brouhaha over a 2010 report that a microbe can incorporate the toxic element arsenic in its cells continues ? though most experts consider the issue settled long ago. A study from Rosemary Redfield?s lab at the University of British Columbia that replicated the original experiments and found no evidence that microbe GFAJ-1 was using arsenic to survive has now been published online in Science (Science News covered it in February).

Science is also publishing a second paper by ETH Zurich microbiologists that comes to the same conclusion: GFAJ-1 is extremely tolerant of arsenic and very good at scavenging phosphorus. That makes it a pretty cool microbe, but poor GFAJ-1 will never live up to its original hype. When you?ve been touted as a New Form of Life, well, Really Good at Finding Phosphorus just doesn?t have the same cachet.

That brings Science, a journal with plenty of cachet, to a total of eight technical comments and two papers unquestionably refuting the original findings by Felisa Wolfe-Simon and her colleagues. Yet their paper still hasn?t been retracted. Why not?

?Ideally a correction or other such statement should be initiated by the authors,? says Ginger Pinholster, director of public programs at the American Association for the Advancement of Science, publisher of Science. ?So we assume that Felisa Wolfe-Simon and her colleagues need time now to review these studies and come to their own conclusions.?

The editorial statement released by Science with the new studies wasn?t quite as forgiving. ?Contrary to an original report, the new research clearly shows that the bacterium, GFAJ-1, cannot substitute arsenic for phosphorus to survive,? it states. ?In conclusion, the new research shows that GFAJ-1 does not break the long-held rules of life, contrary to how Wolfe-Simon had interpreted her group?s data.?

Wolfe-Simon?s statements suggest she may not be ready to reinterpret her results. ?Our data implied that a very small amount of arsenate may be incorporated into cells and biomolecules helping cells to survive in environments of high arsenate and very low phosphate. Such low amounts of arsenic incorporation may be challenging to find and unstable once cells are opened,? she wrote in an e-mail.

But whether Wolfe-Simon and her colleagues ever come around come around may be less important than how the research lives on in the record. More than 90 percent of retracted papers are cited as if they have never been retracted, says Ivan Oransky, executive editor at Reuters Health and cocreater of Retraction Watch, which covers retractions as part of the scientific process. A na?ve reader who lands on the Science page hosting Wolfe-Simon et al?s paper may not know or bother to scroll past the 11 ?suggested reading? links that sit between the original paper and the newly published findings that contradict it.

Found in: Genes & Cells

Source: http://www.sciencenews.org/view/generic/id/342174/title/Arsenic-based_life_gets_even_more_toxic

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