December 19, 2016

expert reaction to multiomics analysis of NK603 GM maize

Publishing in Scientific Reports researchers claim NK603 genetically modified maize and its isogenic control are not ‘substantially equivalent’.

Dr Dan MacLean, Head of Bioinformatics at The Sainsbury Laboratory, said:

“A big issue with this analysis is that materials were collected under potentially quite different conditions. Different parts of the same farm, potentially different chemical makeups in the soil, different water contents, different elevations, exposures and temperatures. Under tight laboratory conditions the metabolome and proteome are very variable and the statistics presented here do not go anywhere near controlling for those factors.

“There are a huge amount of things that could be affecting the expression and levels of everything in those plants and no exploratory and controlling statistics are presented. The analysis just jumps straight into ‘everything is equal, let’s do tests’ and then uses underpowered ones. Much better statistical modelling of the variables is required to allow the workers to definitively ascribe any protein/metabolome changes to any of the experimental variables supposedly under test.

“This has the effect of making the decisions about what pathways are changing moot. No clear conclusions can be reached, and certainly not on the basis of p-values. Hence all downstream analyses could not be expected to show clearly any patterns because of considerable noise in the list of things that are changing.”

Dr Joe Perry, former Chair of the European Food Safety Authority GMO Panel, said:

“In contrast with compositional analysis, which is done for every application, and reported by EFSA, and which involves proper replicated field trials, this study appears to have been done with single, unreplicated plots.

“Therefore it is not possible to say with any certainty whether the differences reported are due to differences between the treatments or differences between the two fields (or two plots within the fields) used.

“In other words the basic tenets of experimental design seem not to have been followed. For that reason I could not yet describe this as a thorough piece of science.

“Further details about the conduct of the experiment would be useful to confirm or otherwise this initial impression.”

Prof. Johnjoe McFadden, Professor of Molecular Genetics at the University of Surrey, said:

“The science is good as far as it goes. But the analysis only emphasises the inadequacy of the ‘substantial equivalence principle’. How equivalent does it need to be? If you perform this detailed level of analysis on any perturbation of any organism you will detect this level of change – organisms are extraordinary sensitive and, for example, similar changes are produced when treated with e.g. pesticide or herbicides¹ or when attacked by pests².

“I would expect that practically any perturbation to an organism will generate a response that can be detected by these powerful techniques – that is after all what life does.

“So all it shows is that GM, like pesticides, herbicides, drought, predation or even growing in a different field will produce a response by the organism. If GM was banned on these grounds then so would all herbicide pesticides and indeed anything that causes a change (which is everything).”

¹ http://www.sciencedirect.com/science/article/pii/S0048357511000472

² http://www.sciencedirect.com/science/article/pii/S0048357511000472

* ‘An integrated multi-omics analysis of the NK603 Roundup-tolerant GM maize reveals metabolism disturbances caused by the transformation process’ by Robin Mesnage et al. published in Scientific Reports at 10am UK time on Monday 19 December.

Declared interests

Dr Perry: “Dr Perry declares no conflicts of interest.  All of his interests are declared on the EFSA website and may be downloaded freely.  He has never received a penny piece for any of his work on GM from any commercial company.”