GRACE publication on Transcriptomics
Scientists form the GRACE consortium evaluated gene expression in rat intestinal tissues based on mandatory 90-day rodent feeding studies with 33% GM maize (MON810) or near-isogenic control maize.
No biological response to the GM-diet was observed in male and in female rat tissues. Transcriptome wide analysis of gene expression by RNA-seq confirmed these findings. Nevertheless, gene ontology (GO) analysis clearly associated a set of distinctly regulated transcripts with circadian rhythms. Differential expression of circadian clock genes was confirmed using RT-qPCR and immunoassays for selected factors, thereby indicating physiological effects caused by the time point of sampling.
Prediction of potential unintended effects of GM-food/feed by transcriptome based profiling of intestinal tissue presents a novel approach to complement classical toxicological testing procedures. Including the detection of alterations in signaling pathways in toxicity testing procedures may enhance the confidence in outcomes of toxicological trials. In this study, no significant GM-related changes in intestinal expression profiles were found in rats fed GM-maize MON810. Relevant alterations of selected cellular pathways (apoptosis, DNA damage and repair, UPR) pointing toward intestinal toxicity of the diets were not observed. Transcriptomic profiles did not reveal perturbations of pathways associated with toxicity, underlining the study results revealed by classical OECD endpoints.
The database CADIMA (Central Access Database for Impact Assessment of Crop Genetic Improvement Technologies) contains quality assessed studies and conclusions on the health effects, socio-economic consequences and environmental impacts of GM plants as well as raw data of animal feeding studies and alternative in vitro approaches.