Are ‘OMICS’ Contributing to the Identification of Unintended Effects in Genetically Modified Crops?

Abstract

One of the initial concerns driving the risk assessment of genetically modified organisms (GMOs) in order to address their safety for human health and the environment has been the question whether techniques of genetic engineering and their molecular processes are inherently causing more unintended effects compared to those involved in traditional biotechnologies (e.g. breeding, chemical mutagenesis or radiation). In the context of genetically modified (GM) food and feed, a major guiding tool to address potential differences between the existing food/feed and the corresponding GM product is the concept of ‘substantial equivalence’ [1]. Based on the consideration that non-GM plants have a long history of safe use, genetically modified plants are compared to their non-genetically modified counterparts (parental or near-isogenic lines) in order to identify differences which are subsequently assessed for their impact on human health and the environment. With this approach, not only differences due the acquisition of the new desired trait (intended by the genetic modification) are assessed, unintended changes (i.e. those which go beyond that of the original genetic modification such as altered expression of untargeted genes or metabolic effects of the novel gene product) are also considered. The term “Omics” refers to studies involving different profiling techniques such as genomics (the quantitative study of genes, regulatory and non-coding sequences), transcriptomics (RNA and gene expression proteomics (protein expression) and metabolomics (metabolites and metabolic networks).Technical aspects in collecting ‘omics’ data set are continuously improving and profiling techniques now serve several distinct purposes. ‘Omics’ have for example the potential to provide complementary or additional tools to compare and study potential intended or unintended differences at the compositional and nutritional level between GMOs and their comparators (e.g. detecting differences in levels of nutrients, anti-nutrients, endogenous toxicants or allergens) or to characterize the GMO responses to environmental factors. Alongside with the progress in the area of ‘omics’ tools, the question has been raised whether there is a need for implementing molecular profiling techniques as a standard prerequisite in the risk assessment (environmental or food/feed assessment) of genetically modified organisms [2-5].