基因流动和和GM作物的环境风险评估.

GeneflowandenvironmentalriskassessmentofGMcrops基因流动和和GM作物的环境风险评估AlanRaybould,EcologicalSciences,Syngenta阿兰.雷博德,生态学部,Syngenta公司2Outline概要Whatisgeneflow?MethodstoestimategeneflowRegulatoryriskandenvironmentalriskHazardandexposureGeneflowinenvironmentalfateGeneflowandweedinessGeneflowandgeneticresourcesDatarequirementsforriskassessmentRiskassessmentframework什么是基因流动?评估基因流动的方法调整风险和环境风险危害和暴露在环境归趋中的基因流动基因流动和杂草基因流动和基因资源风险评估所需的数据风险评估框架3Whatisgeneflow?什么是基因流动?EncyclopaediaBritannica“Introductionofgeneticmaterial(byinterbreeding)fromonepopulationofaspeciestoanother,therebychangingthecompositionofthegenepoolofthereceivingpopulation.”不列颠百科全书“基因(由杂交繁殖产生的)由一个种群传向另一个种群,从而改变了接受基因种群的基因组成”4Whatisgeneflow?什么是基因流动?Anaturalphenomenon–helpsmaintaingeneticvariationOccurswithinandbetweencrops,weedsandwildplantsInplants,themainagentsofgeneflowarepollenandseeds基因流动是自然现象–能够帮助维持基因变化基因流动发生在作物杂草和野生植物之间.在植物中基因流动的主要载体是花粉和种子.5Geneflowviapollen以花粉为载体的基因流动PlantshavemechanismstodispersepollenSomespeciesusewindSmall,unspectacularflowersProducelargeamountsofpollen植物有传播花粉的机制一些物种利用风作为传播花粉的媒介:小且不引人注意的花产生大量花粉Conifers松树TreesGrasse草6Geneflowviapollen以花粉为载体的基因流动SomeplantsuseanimalvectorsInsects(birds,bats,othermammals,slugs…)Attractanimalsbycolour,scentandrewards(pollenandnectar)一些植物以动物为花粉的载体昆虫(以及鸟类,蝙蝠,其他哺乳类动物,蛞蝓…)以颜色,花香和花粉,花蜜来吸引动物Beeorchid–mimicry蜜蜂兰–拟态Dogrose–colour,pollen7Geneflowviapollen以花粉为载体的基因流动Someplantspreventorreduceself-fertilisation某些植物防止,减少自我受精Hop–maleandfemaleflowersonseparateplants蛇麻草-雌雄异体Maize–separatemaleandfemaleflowersonsameplant玉米-雌雄同体但异花Brassica–self-incompatibilit芸苔–自花不育8Geneflowviaseed以种子为载体的基因流动ManymechanismstopromoteseeddispersalWindStructurestokeepseedsairborneAnimalsStructurestocatchthefurofanimalsFruits+hardseedcoattoprotectseedsfromdigestionManWeedsmimiccropsDispersalintimeDormancy有许多促进种子传播的机制风使种子在空气中传播动物种子附着在动物的皮毛上果实和种皮能防止种子被消化人类野草和作物相似及时传播冬眠9Geneflowviaseed以种子为载体的基因流动Dandelion–wind蒲公英–风Falseoat–mimicry伪燕麦–模仿Tomato–fruitandhardseeds番茄–果实和种皮Goosegrass–animalfur牛筋草–动物皮毛10Geneflowanddispersal基因流动和分散GeneflowanddispersalarenotthesamePollenmusteffectfertilisationSeedsmustgerminateandproducereproductiveplantsDispersal=potentialgeneflowFertilisationandproductionoffertileplants=actualgeneflow基因流动和分散是不同的花粉必须能够受精种子必须发育并长成有繁殖能力的植株分散=潜在的基因流动植株的受精和繁殖=真正的基因流动11MethodstoestimategeneflowMethodParameterestimatedSeedtraps1PotentialgeneflowviaseedPollentraps1PotentialgeneflowviapollenMale-sterilebaitplants1PotentialgeneflowviapollenParentageanalysis1ActualgeneflowviapollenPlantswithgeneticmarkers1ActualgeneflowviaseedsandpollenGeneticstructure2Actualgeneflowviaseedsandpollen1Directmethods:estimatecontemporarydispersal;makefewassumptions;weakatdetectingrare,long-distancedispersal2Indirectmethod:estimatesofgeneflowovermanygenerations;detecteffectsofrare,long-distancedispersal;relyon(untestable)assumptionsaboutdemography12评测基因流动的方法评测基因流动的方法方法评测参数种子诱捕1以种子为载体的潜在基因流动花粉诱捕1以花粉为载体的潜在基因流动雄性不育植物1以花粉为载体的潜在基因流动出身分析1以花粉为载体的实际基因流动基因标记1以花粉和种子为载体的实际基因流动基因结构2以花粉和种子为载体的实际基因流动1直接方法:估测同一代传播的花粉;做出一些假设;缺点是检测率低和无法估测长距离花粉传播2间接方法:可以估测不同代传播的花粉;可以检测不常见的作用和长距离的花粉传播;依赖于统计学的假设13Regulatoryriskandenvironmentalrisk管理上的风险和环境风险GeneflowmayleadtounintendedpresenceoftransgenesPresencemaycontraveneregulationsorpermitconditionsUnapprovedEventsoutsidefieldtrialsEventsapprovedforanimalfeedinhumanfoodchainApprovedEventsabovethresholdsinunlabelledbatchesCo-existenceofGMandorganicfarming基因流动会导致转基因的意外出现这种意外会违背规律和允许的条件在农田外未经允许的转基因状况在动物饲料中允许的基因出现在人类食物中在阈值之上的基因出现在未被标记的组中GM和有机作物共存14Regulatoryriskandenvironmentalrisk管理上的风险和环境风险CanleadtofinesandcompensationtoaffectedpartiesPresenceofthegenemayhavenoeffectonsafetyAregulatory(oreconomic)risk,notanenvironmentalrisk会导致对背影响部分的补偿基因的出现可能不会对安全产生影响管理上的(或者是经济)风险,而不是环境风险15Geneflowandenvironmentalrisk基因流动和环境风险GeneflowisanaturalphenomenonTheprocessdoesnotconstituteariskinitselfTheriskresultsfromanyharmfulpropertiesofthegeneHazard=harmfuleffectofthegeneExposure=presenceofthegenewhereitcancauseharmGeneflowispartoftheexposureassessment基因流动是一种自然现象这个过程本身不会产生风险而风险是由基因的负面性质产生的危害性=基因的负面作用暴露=基因的出现导致危害的产生基因流动是暴露评估的一部分16Geneflowandenvironmentalfate基因流动和环境归趋Environmentalfateistheconcentration,distributionandpersistenceofachemicalintheenvironmentAfateassessmentiscarriedoutforGMproteinsDetermineswhichorganismsareexposedtotheproteinSeeExposureCharacterizationthisafternoon环境归趋是某种化学物质在环境中的浓度,分布和持续性.GM蛋白的归趋评估确定哪些生物体暴露于GM蛋白参见今天下午的暴露特性17Geneflowandenvironmentalfate基因流动和环境归趋Geneflowcandispersetheproteintoothervarietiesofthesamecrop(crop-to-crop)tofollowingcrops(viadormancyandvolunteering)tonon-agriculturalhabitats(invasivenessorweediness)tootherspecies(wildplants,horizontalgenetransfer)基因流动是蛋白分散分散到同一作物的不同亚种中(作物-作物)分散到其他作物中(通过休眠体和自生体)分散到非农业环境中(入侵或杂草)分散到其他物种(野生植物,横向基因转移)18Environmentalfate:crop-to-cropgeneflow环境归趋:作物-作物基因流动ForEventsforcommercialsale,itisassumedthatcrop-to-cropgeneflowwilloccurSporadic,lowfrequenciesoftransgenesinnon-GMcropsCalled“adventitiouspresence”EnvironmentalsafetyassessmentwillcoverthispresenceAssessmentforin