Do genetically modified (GM) crops affect.ppt

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1、Do genetically modified(GM)crops affect animal reproduction?A review of the ongoing debateContents1234BackgroundThe effect of GM crops on female and male animal reproductionPossible mechanisms for GM effects on animalsConclusions What are genetically modified(GM)crops?Genetically modified(GM)crops a

2、re identified the crops which use modern techniques of genetic engineering(or biotechnology)to introduce specific genetic material derived from any species of plant,animal,or microorganism,or even synthetic material,into different species of plants.Then,the resulting plants can expressed the novel a

3、nd desirable traits,such as enhancing the disease resistance,anti reversion force and secreting the useful proteins during the different stages of the plant growth.BackgroundTransgenetic technology of plant Image information in product Transgenetic technology and GM crops rapid commercial applicatio

4、nBenefits of Genetic Engineering and ModifyinguIncreased and improved nutrients and stress tolerance.uImproved resistance to disease or illness.u Improved crop resistance to disease,pests,weeds and herbicides,such as herbicide-tolerance(HT)due to glyphosate-insensitive gene enzyme targeted by the he

5、rbicide,5-enolpyruvylshikimate-3-phosphate synthase(EPSPS),derived from soil bacterium Agrobacterium tumefaciens,and soil bacterium Bt(Bacillus thuringiensis).uIncreased food security for growing populations and growth challenges of our world.GM crops rapid commercial applicationGM crops rapid comme

6、rcial applicationGM crops rapid commercial applicationuAllergies and toxicities from new proteins entering the food supply?uAltered nutritional value of food stuffs?uTransfer of antibiotic resistance genes into intestinal bacteria or other organisms,contributing to antibiotic resistance in human pat

7、hogens?uHorizontal gene transfer of gene inserted into GM crops to DNA of human gut bacteria?Are GM crops safe to eat?Effects due to the insertion of genes into chromosomes of crops,and unpredictable alterations and changes in this process.Reproductive toxicity testing is an important assessment for

8、 safety of GM food and feed.Its primary objective is to detect any effects of GM crops or their metabolites on animal reproductive function,especially on the embryo and fetus,embryonic and fetal implantation and loss,fetal weight,and development and reproductive capacity of offspring EFSA GMO Panel

9、Working Group,2008 The effect of GM crops on female and male animal reproductionuShort-term feeding study:exposures are single doses or fractiongted doses no more than one month.uLong-term feeding study:contained subchronic toxicity(a reduction in the tested animals life span by approximately 10 per

10、cent).especially,90-day feeding study was internationally approved,and chronic toxicity(more than 12 months).uMultigeneration feeding study:evaluated the postweaning maturation and reproductive capacity of the pups.Image information in product The effect of GM crops on female animal reproduction The

11、 effect of GM crops on female animal reproduction Image information in product The effect of GM crops on female animal reproduction The effect of GM crops on male animal reproductionThe effect of GM crops on male animal reproduction The effect of GM crops on male animal reproduction Case analysis Im

12、age information in product Their studies are by far the most meticulous and comprehensive feeding trials to date,and confirm deleterious reproductive and health.The researchers at Monsanto Company think that Dr.Velimirovs report lacks sufficient experimental details to fully interpret the results an

13、d contains a number of errors which make it unsuitable for risk assessment and/or regulatory purposes(Monsanto Company,2009).uExogenous protein and effects on gastrointestinal tract Possible mechanisms for GM effects on animalsD-glucose accumulation by pyloric caeca was significantly increased;parti

14、cularly in fish fed GM-soy,and then detected SGLT1 protein which is recognizes a single band around 123 kDa in pyloric caeca BBMVs,the intestinal region where the D-glucose flux is highest.and found expressed high.Bakke-McKellep etal,Research in Veterinary Science.2008 when compared with control mai

15、ze,MON810 maize induced alterations in the percentage of T and B cells and in subpopulations of CD4+,CD8+,T,and T cells in the gut and peripheral sites at weaning and in adult mice fed for 30 or 90 days,respectively,An increase in serum IL-6,IL-13,IL-12,and MIP-1 after MON810 feeding was also found.

16、These results suggested the importance of the gut and peripheral immune response to GM crop ingestion as well as the age of the consumer in the GMO safety evaluation.Finamore et al.,Journal of Agricultural and Food Chemistry.2008 Therefore,considering the adverse effects on gastrointestinal tract,it

17、 is easy to think that those effects would influence absorption of nutrition and subsequently affect animal reproduction.Horizontal gene transfer(HGT)is the non-sexual or parasexual transfer of genetic material between organisms belonging to the same or different species.Of particular concern are pu

18、tative recipient micro-organisms in the digestive tracts of the human and animals,which are especially relevant to the above discussion of antibiotic-resistance genes uExogenous DNA and Horizontal gene transfer The transgenic sequences were not detected in the original samples of ileostomy fluid tak

19、en before consumption of the GM soya meal,but they could be detected at very low copy number once bacteria in these same samples were enriched through serial passage in Luria broth.Netherwood et al.,Nature Biotechnology.2004 A small fragment of the Cry1A(b)transgene was detected in blood,liver,splee

20、n and kidney of the piglets fed for 35 days with diets containing either GM(MON810).Mazz etal,Transgenic Research.2005uAnti-nutrient compounds in GM crops.The potential for anti-nutrients(trypsin inhibitor,phytic acid and raffinose)adversely affecting health either directly or indirectly is well kno

21、wn(EFSA GMO Panel Working Group,2008).In the study by Ermakova et al.(Ermakova,2005),high levels of mortality(55.6%)and decreases in weights of offsprings were reported in female rats fed GM soybean before mating,during mating and throughout pregnancy.In recent years,many controversial studies have

22、been published regarding the effects of GM crops on the reproductive system.As shown in this review,it appears that there is no adverse effect of GM crops observed for many species of animal in acute or short-term feeding studies,but serious debate still surrounds long-term and multigenerational fee

23、ding studies.Therefore,long-term and multigenerational feeding studies are clearly necessary to further investigating on this important issue.Conclusions In recent years,many controversial studies have been published regarding the effects of GM crops on the reproductive system.As shown in this revie

24、w,it appears that there is no adverse effect of GM crops observed for many species of animal in acute or short-term feeding studies,but serious debate still surrounds long-term and multigenerational feeding studies.Therefore,long-term and multigenerational feeding studies are clearly necessary to further investigating on this important issue.ConclusionsThank You!