SAFETY EVALUATION of Specific TRAITS IN Transgenic Crops under Development in Africa

1. SAFETY EVALUATION of Specific TRAITS IN Transgenic Crops under Development in Africa Communicating Biosafety and Regulation of GMOs for Public Health Officers 20-21, September 2012 Dr. Allan Liavoga Bio-resources Innovations Network for eastern Africa Development (Bio-Innovate) - ILRI

2. Presentation Outline GM food safety issues Safety assessment strategy Evaluation of gene products Current knowledge of safety of GMOs

3. Food Crop Biotech Research in Africa • Insect resistance • Herbicide tolerance • Virus resistant • Nutritional enhancement • Drought tolerance International Service for the Acquisition of Agri-biotech Application, 2011

4. Concerns about GM Foods Understanding of risk: • Real and established risk – based on risk assessment • Perceived risk – based on speculation, urban myths and individual beliefs and values often presented as though they were evidence based • Communicating real issues and how they are addressed

5. Safety Issues • What is the possibility that GM foods will be allergenic? • What is the possibility of novel or elevation of existing toxins and/or anti-nutrients being produced in GM foods? • Are there nutritional concerns associated with the modification? • Other unintended but undesirable effects

6. Safety Assessment Strategy • Knowledge of the parent crop and donor organism, molecular characterization of inserted DNA • Application of concept of substantial equivalence • Evaluation of the safety of any proteins and other products expressed by the inserted DNA • Evaluation of the nutritional consequences of the intended alterations

7. Safety Evaluation of Proteins • Risk identification: • History of safe use of or previous dietary exposure • Bio-informatics analysis for potential allergenic and toxic effects • Mode of action and expected effects of the expressed protein in the recipient plant or following consumption • In vitro digestibility of the expressed protein(s) as a measure of the novel protein(s) potential to be an allergen • Risk Characterization: • Toxicology assessment - historically as confirmatory test • Allergenicity test

8. Insect Resistance • Contain genes from Bacillus thuringiesisthat confer resistance to some common insect pests • Production of an insect-specific toxic protein (Cry proteins) • Maize, Cowpea, sweet potato, pigeaon pea and potatoes

9. risk identification • History of safe use – Bt-based pesticide products have been used commercially in sprays for more than 50 years • Bioinformatics – No amino acid sequence similarity to known mammalian protein toxins or allergens • Mode of action • presence of specific receptors on cells of the midgut of insects • only activated by alkaline environment of midgut of susceptible insect larvae • In vitro digestibility - Rapidly degraded under mammalian gastric simulated environment

10. risk characterization • Toxicity Assessment – rodent model • Since cry proteins are insect proteins • No indication of toxicity Assessment • No evidence that insect resistant GM crops so far developed are risker than conventional counterparts

11. Herbicide Tolerance • Confers resistance to specific herbicides e.g. the glyphosate-based herbicide e.g. Roundup • Specifically inhibits the enzyme EPSP synthase critical for the biosyntheses of aromatic amino acids • Glyphosate-tolerant transgenic crops express a version of this enzyme that is derived from Agrobacteriumspecies • Insensitive to glyphosate and thus confers tolerance to glyphosate in the GM crops • Currently being introduced into maize

12. risk identification • History of safe use – EPSPS protein derived from a common Agrobacterium, found ubiquitously • Bioinformatics analysis – No similarity has been found comparing EPSPS protein to known protein toxins and allergens • Mode of action – All plants, bacteria and fungi contain the EPSPS protein but it is not present in mammals including humans • In vitro digestibility – Degrade rapidly in simulated digestive fluid experiments and therefore loss of activity will occur

13. risk characterization • Based on risk identification, no risk identified • Toxicological assessment - Acute oral toxicity studies of the EPSPS protein in mice have shown no adverse effects at high dosage Assessment • No evidence that herbicide tolerant GM crops so far developed are risker than conventional counterparts

14. Nutritionally Enhanced • Engineered to enhance nutritional levels • Biofortified cassava, sorghum and banana – pro-vitamin A, zinc, iron and protein digestibility • Same principle as other traits except: • Assessing human and animal exposure to these products • Is nutritional intake likely to be altered by introduction of GM foods to food supply

15. Conclusion • Scientific consensus by regulatory bodies that there are no food safety issues that are unique to GM technology • GM foods subjected to more rigorous assessment procedures compared to traditional foods • Body of scientific knowledge on safety assessment of GM foods

16. Conclusion • So far no adverse effect have been documented as a result of foods derived from GM crops • Regulations to address safety of GM foods must be robust to ensure safety but not to impede innovation • Ability of regulators to provide scientific opinion on food safety to decision makers will determine rate of uptake of technology

17. “Technology carry risks. The challenge lies in reducing the risks while maximizing the benefits. Not adopting new technologies carries its own risks,” Prof CalestousJuma