转基因生物与生物安全

20世纪70年代以来,以转基因技术为代表的现代生物技术在解决人类所面临的粮食短缺、环境污染等重大问题上发挥了巨大作用,并逐渐发展成为强大的现代生物技术产业。随着各类转基因生物的问世及其产品的不断上市,转基因生物的安全性问题已成为公众关心的焦点。本文分析了转基因生物可能对生物多样性、生态环境和人体健康等方面产生的负面影响,总结丁国内外有关转基因生物安全管理的现状,提出了加强转基因生物安全管理的策略。     

转基因生物及其产品检测技术和标准化

随着转基因生物及其产品的大规模商业化以及消费者对其安全性的担心,很多国家和地区纷纷出台包括转基因产品标签制度在内的转基因生物安全管理的法律法规,为保障转基因产品标签制度的实施以及消费者知情权和选择权,转基因产品检测分析方法及其标准化研究受到人们广泛重视。目前,国内外常用的转基因产品检测方法主要包括针对转基因产品中的目的核酸DNA分子或者其编码的蛋白质分子,本文将对转基因生物及其产品检测方法及其标准化的进展及发展趋势做一概述。     

转基因产品的安全性及其对应策略

目前,生物安全性问题已成为转基因技术及其产品能否获得足够的研究空间和良好开发市场的关键所在。然而,在重视安全性的同时,也必然认识到转基因技术及其产品的出现乃是人类社会发展的客观必然。当务之急不应该是简单地反对或赞成,而是必须对转基因产品进行全面、充分的研究和客观、具体的评价,从而使其在造福于人类的同时,能有效地减少或避免对人类健康及其生存环境可能产生的潜在危害。当然,对社会公众进行科学宣传和指导,从而使其在对转基因产品具有客观了解的基础上培养一种健康的接受心态也是必需的。本在简述转基因产品安全性及其研究现状的基础上,提出若干对应策略,希望能引起社会各界的共识。     

转基因植物的环境生物安全：转基因逃逸及其潜在生态风险的研究和评价

转基因作物的商品化生产和大规模环境释放在带来巨大利益的同时,也引起了全球对其生物安全问题的广泛关注和争议,其中转基因通过花粉介导的基因漂移逃逸到非转基因作物及其野生近缘种,进而导致的潜在环境和生态风险就是备受争议的生物安全问题之一。转基因植物的环境生物安全涉及两方面关键问题：如何科学评价转基因植物商品化种植以后带来的环境和生态影响;如何利用环境生物安全的研究成果来制定科学有效的风险监测和管理措施。对转基因逃逸及其潜在生态风险的科学评价应包括三个重要环节：（1）检测转基因的逃逸的频率;（2）检测转基因逃逸后的表达和遗传规律;（3）确定逃逸后的转基因对野生近缘种群体适合度的影响及其进化潜力,本文将围绕对转基因逃逸及其潜在环境风险的科学评价,以转基因水稻为案例来对转基因逃逸带来生态影响的研究好评价的进展进行简要介绍,并对目前依据风险评价研究成果制定的各种管理策略进行了讨论。只有提高对转基因生物环境安全研究和评价的水平,并制定有效的风险监测和管理措施,才能为我国转基因技术的发展和转基因产品的商品化应用保驾护航。     

理性认识转基因植物食品的安全性

讨论现代生物技术的几个基本概念 ,如转基因生物、基因修饰生物、重组DNA植物以及对转基因植物食品安全性评价框架 ,阐明作者对转基因植物食品安全性的理解。     

紫花苜蓿转基因技术及其应用的研究进展

对农杆菌介导法、电击法、显微注射法及基因枪法等几种常用的紫花苜蓿转基因技术研究进展进行概述。综述利用转基因技术对苜蓿进行品质改良,提高抗逆性、抗病虫害、抗除草剂,以及利用转基因苜蓿作为生物反应器生产植物疫苗、酶制剂和抗体等方面的研究进展及最新研究成果。对目前制约紫花苜蓿转基因技术发展的瓶颈及其生物安全性问题进行分析和讨论,并对其应用前景和商业价值进行展望。     

抗除草剂转基因植物的研究现状

主要对目前在农业上广泛采用的除草剂以及抗除草剂转基因植物的研究现状进行了阐述．介绍了非选择性除草剂和选择性除草剂的分类及其作用机理。并对杂草产生除草剂抗药性的机理进行了分析,此外还介绍了抗除草剂基因的作用机理和对转基因植物所产生的生理作用,另外对抗除草剂转基因植物的生物安全性问题,如对基因飘移和生物多样性的影响进行了讨论,并对新型除草剂的发展方向提出思考。     

提高转基因作物生物安全性的分子策略

随着各类转基因作物的问世及其农产品的不断上市,转基因作物的安全性问题已成为公众关心的焦点。综述了提高转基因作物生物安全性的几种分子策略,其中包括选择标记的去除,转基因的组织特异表达和诱导性表达以及转基因逃逸的控制等。     

转基因植物中外源基因及其表达产物转移的途径

随着转基因植物商品化应用的增多,全面了解转基因植物潜在的生态风险性尤为重要。国内外对“转基因植物中外源基因向野生亲缘物种漂移的可能性”、“昆虫对抗虫转基因植物的耐受性”以及“转基因植物对生物多样性的潜在影响”等问题已进行了广泛研究。对转基因植物中外源基因及其表达产物的几种可能转移途径作了概述。着重介绍了“经花粉散布或与野生亲缘物种杂交等途径引起的外源基因转移”以及“转基因植物对土壤生态系统的影响”等方面的研究情况。此外,还对“鉴定外源基因及其表达产物存在的方法”进行了简要探讨。     

我国转基因水稻商品化应用的潜在环境生物安全问题

转基因水稻的研发和商品化应用将为提高我国水稻的生产力提供新的机遇,并缓解我国的粮食安全问题.转基凶水稻的人规模环境释放和商品化生产可能会带来一定的环境生物安全问题,处理不好会影响转基因水稻的进一步研究和发展.通常所指的环境生物安全问题主要包括以下几个方面:(1)抗生物胁迫转基因对非靶标生物的影响及效应;(2)外源基因向非转基因作物和野生近缘种逃逸及其可能带来的生态后果;(3)转基因作物对农业生态系统、土壤微生物以及生物多样性的潜在影响;(4)抗生物胁迫转基因的长期使用导致靶标生物对转基因产生抗性等.为了安全有效和持续利用转基因生物技术及其产品,有必要对转基因水稻的环境生物安全性进行科学评价.基于风险评价的原则,本文对转基因水稻在我国商品化生产和大规模种植可能带来的环境生物安全问题进行了理性分析,希望为我国转基因水稻商品化应用的决策和生物安全评价提供科学依据.     

Integrated Risk Assessment — Results from an International Workshop

The World Health Organization's International Programme on Chemical Safety and international partners have developed a framework for integrated assessment of human health and ecological risks and four case studies. An international workshop was convened to consider how ecological and health risk assessments might be integrated, the benefits of and obstacles to integration, and the research and mechanisms needed to facilitate implementation of integrated risk assessment. Using the case studies, workshop participants identified a number of opportunities to integrate the assessment process. Improved assessment quality, efficiency, and predictive capability were considered to be principal benefits of integration. Obstacles to acceptance and implementation of integrated risk assessment included the disciplinary and organizational barriers between ecological and health disciplines. A variety of mechanisms were offered to overcome these obstacles. Research recommendations included harmonization of exposure characterization and surveillance methods and models, development of common risk endpoints across taxa, improved understanding of mechanisms of effect at multiple scales of biological organization, and development of methods to facilitate comparison of risks among endpoints.     

Current risk assessment approaches for environmental and food and feed safety assessment

Foundational activities at the international level underlie current risk and safety assessment approaches for genetically engineered/modified organisms (GEOs/GMOs). Early risk assessment considerations beginning with the OECD ‘Blue Book’ established risk/safety assessment as the characterization of the organism and its environmental release; establishment and persistence in the environment; and human and ecological effects, analyzed in principle through existing methods. Important in this context was recognition that GEOs/GMOs as a class did not represent new risks relative to products of traditional plant breeding and that any incremental risk would need to be established on a stepwise case-by-case comparative basis with existing crops and derived-foods as the baseline. Accordingly, concepts of familiarity and substantial equivalence were advanced by OECD and WHO as ways to establish a risk analysis baseline for determining whether and to what extent risk/safety assessment was needed. Regulatory implementations of this paradigm have skewed to increasingly complex portfolios of studies rather than adhering to analysis which is formulated to fit the risk/safety questions relevant to a given case. Plants produced through genome editing technology will benefit from risk analysis that implements sound problem formulation to guide the need for and nature of risk/safety assessments.

     

Approaches for Integrated Risk Assessment

Recognizing the need to enhance the effectiveness and efficiency of risk assessments globally, the World Health Organization's International Programme on Chemical Safety, the U.S. Environmental Protection Agency, the European Commission, and the Organization for Economic Cooperation and Development developed a collaborative partnership to foster integration of assessment approaches used to evaluate human health and ecological risks. The objectives of this effort included: improving understanding of the benefits of integration, identifying obstacles to the integration process, and engaging key agencies, organizations, and scientific societies to promote integration. A framework with supporting documentation was developed to describe an approach for integration. Four case studies were constructed to illustrate how integrated risk assessments might be conducted for chemical and nonchemical stressors. The concepts and approaches developed in the project were evaluated in an international workshop. The goal of this effort was international acceptance of guidance for integrated risk assessment.     

Relative risk assessment for ballast-mediated invasions at Canadian Arctic ports

Vector-based risk assessment is a powerful and efficient management approach for nonindigenous species (NIS). By managing a vector, an entire assemblage of associated NIS is simultaneously considered. The majority of current risk assessment frameworks have been conducted for a single, or selected few, target species and thus are not useful for managing vectors transporting a large number of potentially unknown species. Here we develop a predictive framework to assess relative invasion risk for a vector (ballast water) transporting an unknown species assemblage, using the Canadian Arctic as a case study. Ballast water discharge is a known high-risk vector globally, but its magnitude in the Arctic has not been well characterized. Our framework determined relative invasion risks between different transit pathways by quantifying the probability of NIS successfully transiting all stages of the invasion process and the magnitude of consequences of introduction to those ports. Churchill, Manitoba was ranked at ‘higher’ invasion risk via ballast water discharged by international merchant vessels than any other recipient port studied. The overall pattern of ballast water discharge suggests that water originating from coastal domestic sources carried by international merchant vessels may be important for dispersal of NIS. In addition, ballast-mediated NIS are more likely to arrive to the Hudson Bay region during summer months. These results can be useful for developing prevention and early detection programs for the region. Our risk assessment framework is not limited to ballast water and could be applied to other vectors for effective management of NIS.     

HIV international clinical research: exploitation and risk

This paper aims to show that to reduce the level of exploitation present in (some) international clinical trials, research sponsors must aim to provide both an ex-ante expected gain in utility and a fair ex-post distribution of benefits for research subjects. I suggest the following principles of fair risk distribution in international research as the basis of a normative definition of fairness: (a) Persons should not be forced (by circumstance) to gamble in order to achieve or protect basic goods; (b) In cases where one party is gambling with basic goods and the other party is not, the distribution of benefits and burdens must be arranged so that they are of greatest benefit to the worst off; (c) In relationships where one party is gambling for basic goods and the other party is not, the party gambling for basic goods must be assured of some guaranteed benefits in addition to the chance of getting some practical benefits. These principles are applied to the case of HIV international research. I conclude that the research (as described) is mutually advantageous but still exploitative because the distribution of surplus benefits is unfair. It is unfair because research subjects are gambling with and for basic goods but they are not assured of a fair ex-post distribution of benefits. Principles (b) and (c) are not satisfied. Research participants are not accorded enough guaranteed benefits to outweigh the risks they undertake.     

Assessing the port to port risk of vessel movements vectoring non-indigenous marine species within and across domestic Australian borders

Biofouling of vessels is implicated as a high risk transfer mechanism of non-indigenous marine species (NIMS). Biofouling on international vessels is managed through stringent border control policies, however, domestic biofouling transfers are managed under different policies and legislative arrangements as they cross internal borders. As comprehensive guidelines are developed and increased compliance of international vessels with 'clean hull' expectations increase, vessel movements from port to port will become the focus of biosecurity management. A semi-quantitative port to port biofouling risk assessment is presented that evaluates the presence of known NIMS in the source port and determines the likelihood of transfer based on the NIMS association with biofouling and environmental match between source and receiving ports. This risk assessment method was used to assess the risk profile of a single dredge vessel during three anticipated voyages within Australia, resulting in negligible to low risk outcomes. This finding is contrasted with expectations in the literature, specifically those that suggest slow moving vessels pose a high to extreme risk of transferring NIMS species.     

区域生态系统风险管理的EVR模型及其应用研究

系统探讨了生态风险的成因、内涵;结合当前国际上流行的VaR风险管理模型,在生态风险理论有关研究的基础上．建立了一类新颖而实用的区域生态系统风险管理模型-EVR。并对模型的特点、性质、建模思想、参数选取的进一步完善和改进工作进行了详细的阐述。最后,以干旱风险为例,对EVR模型进行了应用研究。     

地中海实蝇与植物检疫

地中海实蝇Ceratitis capitata (Wiedemann)是国际上十分重要的检疫性害虫,也是我国植物检疫工作中重要防御的检疫性害虫之一,近年来,从我国口岸检疫中共截获地中海实蝇12次。这充分表明了其潜在的危险性。为此,我国采取了一系列严格的检疫措施,有效地防止地中海实蝇传入。同时,为适应改革开放和国际贸易的发展,对检疫政策进行了调整,积极开展对水果、蔬菜的有害生物风险分析(PRA)研究工作,根据国际标准,划定非疫区范围,使植物检疫对贸易的不利影响降到最低限度,以促进水果、蔬菜进出口贸易的发展。     

Integrating bioclimate with population models to improve forecasts of species extinctions under climate change

Climate change is already affecting species worldwide, yet existing methods of risk assessment have not considered interactions between demography and climate and their simultaneous effect on habitat distribution and population viability. To address this issue, an international workshop was held at the University of Adelaide in Australia, 25–29 May 2009, bringing leading species distribution and population modellers together with plant ecologists. Building on two previous workshops in the UK and Spain, the participants aimed to develop methodological standards and case studies for integrating bioclimatic and metapopulation models, to provide more realistic forecasts of population change, habitat fragmentation and extinction risk under climate change. The discussions and case studies focused on several challenges, including spatial and temporal scale contingencies, choice of predictive climate, land use, soil type and topographic variables, procedures for ensemble forecasting of both global climate and bioclimate models and developing demographic structures that are realistic and species-specific and yet allow generalizations of traits that make species vulnerable to climate change. The goal is to provide general guidelines for assessing the Red-List status of large numbers of species potentially at risk, owing to the interactions of climate change with other threats such as habitat destruction, overexploitation and invasive species.