Biosafety Issues and Risk Assessment in Transgenic Crops

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1 Biosafety Issues and Risk Assessment in Transgenic Crops K.C. Bansal National Research Centre on Plant Biotechnology Indian Agricultural Research Institute New Delhi

2 Biotechnology is an Extension of Traditional Plant Breeding RADITIONAL PLANT BREEDING NA is a strand of genes, much like a strand of pearls. Traditional plant breeding ombines many genes at once. Many genes are transferred Desired Gene X Donor Plant LANT BIOTECHNOLOGY Commercial Plant Variety sing plant biotechnology, you can add a single gene to the strand. New Plant Variety A single gene is transferred Desired Gene Donor Desired Gene + Commercial Plant Variety Improved Commercial Plant Variety

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4 Genetic Engineering : Recombinant DNA technology

5 These products have undergone a comprehensive and rigorous assessment process to validate their safety...

6 What is BIOSAFETY? Biosafety means - protecting human and animal health and environment from the possible adverse effects of the products of modern biotechnology

7 Biosafety issues in transgenic crops Relate to environmental, human and animal health consequences Both can have short and long term implications Biosafety risks involve the entire spectrum of biodiversity A universal true for all approach may not be applicable Risks Known Probability Unknown Probability Rigorous Scientific Assessment Risk Mitigation Precautionary Principle

8 ..Biosafety issues in transgenic crops Biosafety concerns arise from: Horizontal gene transfer Genetic contamination Transfer of allergens and toxins from one life form to another and creation of new toxins and allergenic compounds

9 ..Biosafety issues in transgenic crops Main Concerns Development of aggressive weeds/ wild relatives by transfer of transgenic traits Erosion of land races/wild relatives by genetic pollution in centres of origin/ diversity Harm to the non-target organisms Development of pest resistance by prolonged use Monoculture and limitations to farmers choice in crop management Hazard to human and animal health by transfer of toxins and allergens and by creation of new toxins and allergenic compounds

10 ..Biosafety concerns addressed Two main stages: 1. Laboratory/green house stage 2. Confined Trial Stage IMPORTANT Prevention of the spread of genetically engineered material outside lab/field

11 Focus on Risk Mitigation Risk mitigation the terms and conditions that are necessary to conduct the trial safely Prevent Gene Flow Prevent entry of GMOs into food chain Prevent Persistence of GMOs in the field

12 Biosafety Parameters on Transgenic crops A. General information Rationale for the development Description of the host plant Mode of Pollination Centres of Origin/diversity of the crop species Geographical distribution of the target crop and sexually compatible plant species including wild relatives contd... 12

13 Biosafety Parameters on Transgenic crops B. Biosafety Parameters: 1. Genetic and molecular parameters Genetic analysis including copy number of inserts Stability of the gene Level and duration of expression of the transgene Characterization of the expressed gene product Efficacy/utility of the gene product Compositional analysis contd... 13

14 Biosafety Parameters on Transgenic crops 2. Environmental parameters Gene flow Implications of out-crossing Effect on target and non-target organisms Effect on soil biota 14

15 * Effect on fish Biosafety Parameters on Transgenic crops 3. Toxicity parameters including histo-pathological studies (need based) Food/feed safety evaluation in animals such as: * Effect on small laboratory animals * Effect on livestock animals (representative goat studies of large animals) * Effect on birds/ avian species

16 Biosafety Parameters on Transgenic crops 4. Allergenicity parameters (need based) Primary skin irritation test in rabbit/ guinea pigs Irritation to mucous membrane test in rabbit/ guinea pig Immunological responses in suitable animal system Contd.

17 Biosafety Parameters on Transgenic crops C. Agronomic parameters Efficacy of the gene at phenotypic level Yield Growth and developmental parameters Responses to major diseases and insect-pests Quality parameters Economic evaluation/ cost: benefit ratio

18 The safety of biotech products is established through the following approach Gene / Protein Safety Gene(s) Source(s) Molecular characterization Insert / copy number / gene integrity Protein(s) Food/Feed and Environmental Safety History of safe use and consumption Function / specificity / mode of action Levels Toxicology / allergenicity testing Environmental Safety Crop Safety Crop Characteristics Morphology Yield Food/Feed Composition Proximate analysis Key nutrients Key anti-nutrients

19 Safety of the Genes Detailed map of vector Identity of all genetic components of vector Portion and size of inserted sequences The function of the genetic component in the plant The source of the genetic component Inheritance and stability of trait

20 Safety of the Proteins Indicate if there are changes in the amino acid sequence from the native protein Submit data indicating if the protein is expressed as expected Compare novel protein sequence to known toxins and allergens Acute/Chronic testing, mouse In vitro digestibility assay.

21 Comparison to toxins or allergens The protein is compared to proteins in large global databases More than 100,000 different proteins are searched A Macro comparison looks at the whole protein A Micro comparison looks at small stretches of the protein As few as 8 amino acids are compared For the Cry proteins, more than 600 searches are performed across the entire protein length

22 Safety assessment summary for GM crops Component Agronomy Environmental safety Composition Additional gene(s) / protein(s) Introduced trait(s) Changed Unchanged

23 Livestock Feeding Studies - GM Crops animal feed studies utilizing biotech crops

24 Performance Confirmed (Over 60 References) Animals fed biotech products perform in in a comparable manner to to animals fed traditional products No Significant Differences in: Feed Intake Body Weight Carcass Yield Feed Efficiency Milk yield Milk composition Digestibility Product Composition/ Quality

25 DNA and Protein Digestion DNA and proteins are natural and abundant components of our diet All DNA and proteins including those from plants improved through biotechnology are made up of the same building blocks subject to the same digestion conditions The normal digestion conditions rapidly break down DNA and proteins into smaller pieces that serve as important nutrients Simulated gastric digestibility of introduced proteins is a part of the product safety assessment 4/3/

26 Mycotoxins Have Significant Health Concerns Carcinogenic to rats and mice (National Toxicology Program) Epidemiology evidence of esophageal cancer in humans Liver damage in swine; also in cattle at higher doses Possible role in neural-tube birth defects in humans Because ears and grain from Bt corn are protected from damage by insects, they are less contaminated by fusarium and fumonisin than conventional corn Fusarium Ear Rot Mycotoxin Levels Infected Kernels / Ear '95 '96 '97 '98 Non-Bt YieldGard Fumonisin (PPM) '97 '98 Non-Bt YieldGard Source: Iowa State University Research, natural European corn borer infestations

27 Summary Biotech crops are safe. Approved recombinant products have passed and often exceeded the appropriate regulatory requirements. Transgenic plant DNA and protein have NOT been detected in meat, milk and eggs to date. Animal performance studies have confirmed safety and nutritional equivalence of approved recombinant products. 4/3/

28 Summary.. Biosafety regulations in place to assess the safety of transgenic crops before release Biosafety concerns being addressed in a scientific manner Continuous evolution and flexibility necessary

29 Thank You!