What collateral damage can occur from the process of inserting the foreign gene into the seed during genetic modification?

Expert response from GMOAnswers Admin_1

Tuesday, 03/12/2013 13:49

Thanks to the genomics revolution and new molecular tools, such as “genome editing”, very specific genetic changes can be easily made to plant genomes, from single nucleotide changes to the insertion or deletion of whole genes (Cressey, 2013; Li, 2013). Genomic changes or “events” moving forward for potential commercialization are well-characterized, from the molecular level through to the performance of the whole organism. Thanks to the relative ease and affordability of DNA sequencing, plant genetic engineers use bioinformatics to confirm the changes made to the plant genome, looking for variation in gene expression (transcriptomics) or protein production (proteomics), relative to the parental crop variety (Houston, 2013; Ricroch, 2013).  In addition to molecular assays, tissue and whole organism (greenhouse and field) screens look for changes in growth, development and physiology. Ultimately, there are a standard range of nutritional assessments conducted on the food portion of new biotech crop varieties to make sure there is substantial equivalence to parental varieties.  Using this multilevel biological assessment, any gene insertion "events" causing undesirable changes are easy to pick out and eliminate (Ricroch, 2013).

Farmers require robust, high-yielding crop varieties and biotech seeds have to perform in the field as well, if not better, than conventional seeds in order to compete in the marketplace. Plant breeders working to develop new crop varieties using conventional or biotech tools aim to meet this high standard and eliminate poorly-performing crop varieties early in development. Using either approach, the vast majority of new varietal lines are screened out during the R&D process.  In biotech, on average, ~6000 genomic “events” are initially characterized and only one will be commercialized as a new crop variety (Phillips McDougal Study, CropLife International, 2011). Studies of compositional changes between related (parental vs. derived) crop varieties have consistently shown that conventional breeding techniques, including mutation breeding, cause greater genomic and compositional changes than the precise genomic changes incorporated using biotechnology (Herman, 2013; Ricroch, 2013).