PLOS ONE has retracted two 2014 papers from a group of researchers, after an institutional investigation confirmed image duplication. Although the authors initially asked to correct the figures in the two papers, they ultimately agreed with the decision to retract.
Mrinal K. Maiti—an associate professor at the Indian Institute of Technology at Kharagpur and corresponding author on the two now-retracted PLOS ONE papers—also corrected a 2016 paper published in PLOS ONE over figure-related errors. Maiti is the only author in common to all papers.
A spokesperson for the journal told us:
The institutional investigation covered all three articles; the institution made different recommendations based on the details of each case.
One paper was retracted three years after the journal received a query from a reader. Once the authors and journal settled on a retraction for both papers, the notices didn’t appear until one year after the authors approved the text, according to Maiti. We asked a spokesperson about the timeline, but she said the journal had no “further information.”
Maiti told us the authors agreed with the institute’s recommendation, but explained that the duplication was “unintentional” and did not affect the results or conclusions in either paper.
The road to retraction
According to an extensive PubPeer thread, in April 2014, a reader contacted the journal with concerns about images in the PLOS ONE paper published that month. Maiti told us that the authors heard from the journal about the duplication in December 2014. Although Maiti declined to send us his correspondence with the journal, he said the authors responded to the journal’s queries immediately and shared the raw data for those experiments:
We were also worried about this issue, and expressed our concern during that time how to correct (as a corrigendum or replacement of those figures).
According to Maiti, in March 2016, PLOS ONE contacted him about image duplication in the other now-retracted paper (also flagged on PubPeer).
Maiti said he told the journal that the authors had unintentionally duplicated a few images “while compiling/organizing the numerous experimental data/images into meaningful figures.”
Maiti also told us that the authors had performed three replicates of each experiment in the two papers, but were unable to retrieve some photographs from the first experiments (“Replica1”):
however, we had all our Replica2 & Replica3 experimental data/photographs of the same experiments (as we performed setup in triplicate), and provided all the raw data/photographs to the journal…
Although these replica images supported the same results and conclusions, Maiti said “the journal expressed concern about image duplication among figures presented in the articles and about the lack of the raw data underlying the images included in the published figures (Replica 1 data).”
As a result, the journal would not permit the authors to correct the figures. Maiti told us that, in May 2016, the authors asked the journal to retract or withdraw the two papers because the issues are “creating confusion” in the scientific community “for a prolonged time period.”
According to Maiti, in June 2016, the journal asked the Indian Institute of Technology to investigate the image duplication. That month, the Institute sent the journal a report, recommending the two papers be retracted.
On Oct. 12, 2016, PLOS ONE sent Maiti a draft of the retraction notices to review, which the authors approved just over a week later, and requested “immediate publication.”
Almost a year later, on Oct. 23, 2017, the journal published the retraction notices.
The notices
The notice for the April 2014 paper, “Functional Characterization of Two Structurally Novel Diacylglycerol Acyltransferase2 Isozymes Responsible for the Enhanced Production of Stearate-Rich Storage Lipid in Candida tropicalis SY005,” states:
The authors and editors retract this publication [1] following an investigation into concerns around the images presented in several figures. After the publication of this article, readers raised concerns about potential image duplications in Figures 4A-C, 5A-B, 6C, 7A, and 7C. Specifically,
- There are similarities between gel bands in Figure 4C and Figure 7B.
- The backgrounds and first two lanes of Figures 4A and 7C appear to be identical.
- Figure 4B: there are areas of overlap between figures in the WT, QM-CtDGAT2a and QM-CtDGAT2b panels.
- Figure 5A: there are duplications between different yeast growth panels within the figure.
- Figure 5B: there is a duplication between the left plates for C18:3 and C20:4.
- Figure 6C: several yeast growth images appear to be derived from the same source image, involving panels ΔD2, ΔD4 and ΔD5.
- Figure 7A: There appear to be areas of overlap between the right panels for ΔD1(1–21) and ΔD5(481–571).
The concerns were brought to the attention of the authors, who provided replicate images of the same experimental sets but were not able to provide the images underlying the figures included in the article.
An institutional investigation conducted by The Indian Institute of Technology at Kharagpur confirmed the duplication of images and recommended the retraction of the article.
The preparation of the figures falls below the standard of publication; in light of these concerns and in line with the institutional recommendation, the authors and the editors retract this publication.
The authors sincerely apologize to the scientific community for the errors in the published article.
The paper has been cited seven times, according to Clarivate Analytics’ Web of Science; once by the notice and once since the authors say they approved the retraction.
Here’s a similarly worded retraction notice for the November 2014 paper, “Enhancement of Lipid Productivity in Oleaginous Colletotrichum Fungus through Genetic Transformation Using the Yeast CtDGAT2b Gene under Model-Optimized Growth Condition,” which highlights the problematic images: Figures 1E, 2E-F, and 3A. The paper has been cited three times; once by the notice and twice since the authors say they approved the retraction.
The correction
The institute also examined potential image duplication in a third PLOS ONE paper, which Maiti said is “completely different” than those in the first two. He explained that the image duplication in one figure was “intentionally done” to make a comparison, but the authors “forgot to mention” the duplication in the figure legend. The notice also details an error introduced in figure 6, which the authors corrected.
Here’s a link to the correction notice for “Enhanced Gene Expression Rather than Natural Polymorphism in Coding Sequence of the OsbZIP23 Determines Drought Tolerance and Yield Improvement in Rice Genotypes,” which has been cited six times.
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interesting story though! It is surprising that it took one year for the retraction.