This past April, Amparo Acker-Palmer and colleagues published a study in Nature, “Ephrin Bs are essential components of the Reelin pathway to regulate neuronal migration.” Within a day of its publication, Nature readers were raising questions about many of its figures. They started like this:
Andy Gu said:
Looks like Fig 1a, the two middle figures are actually the same with little move from desired regions. I don’t trust their data now…..
After several such comments, Nature senior editor Noah Gray weighed in:
Many thanks to all who have pointed out potential irregularities in the figures of this manuscript. The issue is currently under investigation by Nature, with the full cooperation of the authors, and we will move quickly to bring this issue to conclusion. Both editors and authors are committed to ensuring that the scientific record is accurate and are thus working diligently to restore confidence in the results. Thank you for your patience.
A few Retraction Watch readers have brought this exchange to our attention, and suggested that a retraction was in order, so we’ve been keeping an eye out. Nature has acted, but rather than a retraction, the journal has issued a correction. It’s a whopper:
In this Letter we made errors in representative image choice, including mislabelling of images or choosing an image from the inappropriate genotype. In all cases, choice of images was completely independent of the data analysis and so none of the conclusions in our original Letter are affected. We apologise for any confusion these errors may have caused.
Figure 1a depicts a Tbr1 staining of the adult mouse cortex for four different genotypes. In the process of choosing representative pictures that reflect the results of our analysis shown in Fig. 1b, cropped images from original pictures were inadvertently mislabelled and used incorrectly. We provide below a corrected version of Fig. 1a with new representative images for the following genotypes: WT and Reln1/1;Efnb32/2. A new high-magnification picture for WT is also shown in the two rightmost panels. Original images for every genotype and additional examples are shown in the Supplementary Information of this Corrigendum.
Figure 1c depicts a Brn1 staining of the E17.5 mouse cortex for five different genotypes. In the process of figure assembly cropped images from original pictures were inadvertently mislabelled and used incorrectly. We provide below a corrected Fig. 1c with a new image for Reln1/1; Efnb3–/–. In the ephrinB3 compound mice (Reln1/2; Efnb32/2) Brn11 cells aberrantly accumulate in the lower layers of the cortex and do not migrate to the upper layers, resembling the Reeler (Reln2/2) phenotype. Original pictures and additional examples are shown in the Supplementary Information of this Corrigendum, where arrows indicate the distribution of Brn11 cells. We have also included results from a new, reproduced experiment recently performed with an additional cohort of animals that shows exactly the same results.
In Fig. 1d, the second panel, labelled ‘Reln1/1;Efnb3–/–’ should instead be labelled ‘Reln1/2’. In the Methods summary section ‘Stimulation of neurons’, ‘‘Cortical neurons from E14.5 were grown….’’ should instead read ‘‘Cortical neurons from E15.5 were grown….’’.
There were mistakes in the supplementary online material, too:
Further errors in the Supplementary Information of the original Letter are described and corrected in the Supplementary Information of this Corrigendum.
We thought this was quite an extensive collection of errors, so we wanted to know why Nature thought a correction was a better way to deal with them than a retraction. The journal responded (emphasis theirs):
Please see the definitions for corrigenda and retractions in the Nature journals. In this case a corrigenda was appropriate since the finding in the paper remains unchanged.
A Corrigendum is a notification of an important error made by the author(s) that affects the publication record or the scientific integrity of the paper, or the reputation of the authors or the journal. All authors must sign corrigenda submitted for publication. In cases where coauthors disagree, the editors will take advice from independent peer-reviewers and impose the appropriate amendment, noting the dissenting author(s) in the text of the published version.
A Retraction is a notification of invalid results. All coauthors must sign a retraction specifying the error and stating briefly how the conclusions are affected, and submit it for publication. In cases where coauthors disagree, the editors will seek advice from independent peer-reviewers and impose the type of amendment that seems most appropriate, noting the dissenting author(s) in the text of the published version.
We were also curious about the new results presented in the Corrigendum:
We have also included results from a new, reproduced experiment recently performed with an additional cohort of animals that shows exactly the same results.
We’ve seen claims like this before, in other journals, and at least one of those journals said it hadn’t even looked at the new data. Here, at least Nature is making it available. We wondered if Nature typically peer-review statements made in corrections and retractions, and whether they’d peer-reviewed this particular set of new results.
Nature would only sat that peer review is confidential, and that it would be best if we spoke to the authors. We tried to do that, but the corresponding author hasn’t responded to our requests for comment.
We’ll update with anything we find out.