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1.
编码环羟基化加氧酶的基因常作为评价环境中微生物降解芳香族化合物能力的分子标记.近年宏基因组学技术的出现极大地加速了对环境中功能基因及功能类群的研究.本文总结了目前关于芳香族化合物环羟基化加氧酶基因的数据库,介绍了微生物降解芳香族化合物(苯系物、萘及其它多环芳烃)过程中发挥重要作用的各类功能基因,总结了环境检测中使用的分子引物,并综述了它们在各类复杂环境样本中的检测应用,此外对使用宏基因组技术来研究微生物在环境中降解芳香族化合物的能力进行了总结与展望.  相似文献   

2.
Many genetically modified plants have been developed, and four of them (soya, maize, cotton, and colza) representing more than 99% of commercial crops, are widely distributed, mainly in the United States and in America [ISAAA, 2006. Report on global status on biotech/GM crops, Brief 35. International Service for the Acquisition of Agri-biotech Applications organization, US]. Yet all over the world policy is still in development in regard to authorization of modified plants and modified and/or cloned animals for food or feed and for their environmental release. The most advanced animal commercial projects concern various fish species, more easy to genetically transform, notably because conception and development take place in water and easy access to numerous eggs. A request for authorization to introduce genetically modified (GM) salmon onto the market has been presented to the Food and Drug Administration (FDA) of the US. In the interim, questions have been raised concerning the impacts of transgenic salmon, modified for productivity, on aquaculture, wildlife, ecosystems and on human health. Herein we review these scientific studies and sanitary, environmental, social and economic arguments. This paper analyses current gaps in the knowledge of the impacts of transgenic fish and proposes legislation orientations necessary for environmental and sanitary protection, should the marketing of animal genetically modified organisms (GMOs) be authorized.  相似文献   

3.
多溴联苯醚(polybrominated diphenyl ethers,PBDEs)作为一种良好的溴系阻燃剂被大量地添加到工业产品中,随着产品的使用、回收和废弃处理会进入各种环境介质中,是一类分布十分广泛的持久性有机污染物.PBDEs的衍生物羟基化多溴联苯醚(hydroxylated polybrominated diphenyl ethers,OH-PBDEs)和甲氧基化多溴联苯醚(methoxylated polybrominated diphenyl ethers,MeO-PBDEs),由于具有比母体化合物更大的毒性效应和更复杂的环境行为也受到人们广泛关注.通过对PBDEs及其衍生物在土壤中的分布特征、转化规律及生物效应研究的最新进展进行综述发现,PBDEs在土壤中的分布浓度随离工业区距离增加而减小,且大多数污染地区土壤中以高溴代PBDEs为主,偏远地区土壤中则以低溴代PBDEs为主.进入土壤的PBDEs在动物、植物体内及微生物作用下均可发生脱溴代谢转化产生低溴代PBDEs,也可发生羟基化生成OH-PBDEs和甲氧基化生成MeO-PBDEs,与此同时,OH-PBDEs和MeO-PBDEs之间也会发生相互转化.PBDEs及其衍生物作为一种环境内分泌的干扰物对大部分的植物、动物都有显著的毒性效应,对植物而言能够抑制植物种子萌发、幼苗生长、损伤细胞结构以及影响植物代谢活动等;对动物而言能够影响动物的内分泌功能、妨碍动物生殖系统的发育以及对神经系统产生毒性等.目前,关于PBDEs及其衍生物在土壤生态系统中环境化学行为和生态毒性的报道十分有限,探讨土壤中PBDEs的代谢转化过程和毒性效应可为全面深刻地认识PBDEs的环境行为和潜在生态风险提供科学参考.   相似文献   

4.
Flowers adapted for hummingbird pollination are typically red. This correlation is usually explained by the assertion that nectar- or pollen-stealing bees are “blind” to red flowers. However, laboratory studies have shown that bees are capable of locating artificial red flowers and often show no innate preference for blue over red. We hypothesised that these findings might be artefacts of the simplified laboratory environment. Using bumblebees (Bombus impatiens) that had been trained to visit red and blue artificial flowers, we tested whether colour preference was influenced by complexity of the background on which they were foraging. Many bees were indifferent to flower colour when tested using a uniform green background like those commonly used in laboratory studies, but all bees showed strong colour preferences (usually for blue) when flowers were presented against a photograph of real foliage. Overall, preference for blue flowers was significantly greater on the more realistic, complex background. These results support the notion that the red of “hummingbird syndrome” flowers can function to reduce bee visits despite the ability of bees to detect red and highlight the need to consider context when drawing inferences about pollinator preferences from laboratory data. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

5.
水体类固醇雌激素污染现状研究进展   总被引:2,自引:0,他引:2  
都韶婷  金崇伟  刘越 《环境科学》2013,34(9):3358-3367
类固醇雌激素被认为具有极强的内分泌干扰性和生物活性,在极低浓度下就能引起人体或动物生殖障碍、行为异常和幼体变异等.由于水体中的类固醇雌激素的生态环境效应最为直接,因此,本文综述了近年来关于水环境中几种常见的类固醇雌激素的基本特征、污染现状、来源及迁移过程的研究,以期为类固醇雌激素的水处理技术研究提供基础信息.  相似文献   

6.
In many mammalian species, male reproductive success appears to climb sharply at young adulthood, form a brief plateau during prime ages, and decline among older animals, a pattern often attributed to reduced physical condition with ageing. However, solid evidence to either substantiate or refute this profile among nonhuman primates is lacking. Here, we combine a decade of genetic analysis of paternity among free-ranging rhesus macaques, Macaca mulatta, with information about body condition in order to evaluate how changes in morphology might govern age-specific reproduction among males. We show that age-specific reproductive success traverses the same life history profile as found in other mammals, but reductions in reproductive output with advanced age were associated with reduced chances of survivorship rather than accompanied by diminished body condition. We demonstrate that variance in male age at onset of reproduction is three times greater than variance in female age at onset of reproduction. We provide the first evidence from primates that age-specific reproductive output among males is not a consequence of age-related changes in body condition, but reflects social and demographic factors.  相似文献   

7.
In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.  相似文献   

8.
滇池水体中主要藻种毒素研究   总被引:12,自引:0,他引:12  
蓝藻,绿藻和硅藻是滇池的优势藻种,蓝藻“水华”含有毒素,微囊藻毒素分子量为904,实验中可使小白鼠肝脏充血肿大致死。滇池外虽然处于富营养化状态,但水体中藻毒素含量还比低,尚不会对动物及体产生大的毒害作用。  相似文献   

9.
A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides ASI. 1737. The enzyme,with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.  相似文献   

10.
   My concern is to question the quality and utility of science in general and ethology in particular as applied to animal welfare. This topic has in the past provoked me to some severe criticism, for example, 'A lot of well-intended welfare research is neither very good science nor very helpful to the animals.... Too much welfare research is (in my opinion) flawed either because it is oversimplistic, or because it is not so much designed to test preconceptions but to reinforce prejudice' (Webster 1994). Dawkins (1997) has recently responded to this challenge, addressing the question 'Why has there not been more progress in welfare research?' Her response is concerned largely with applied ethology. My own criticism was not directed at ethologists in particular. I was more concerned by the misuse of scientific method by those who seek to obtain a so-called 'objective' measurement of something which they preconceive to be a stress (e.g. measurement of plasma concentrations of cortisol or endorphins in animals following transportation). Here the 'objective' measure frequently becomes the test that gives the answer that they want, and if it fails, then they seek other 'objective' markers until they achieve a set of measurements that supports the subjective impression which they had at the outset. My second main concern is that the welfare state of a sentient animal is a very complex affair and cannot be embraced by any single scientific discipline, be it ethology, physiology, molecular or neurobiology. Unfortunately it is also too complex to be embraced by a single-sentence definition. The best I can do is to suggest that it is determined by the capacity of an animal to sustain physical fitness and avoid mental suffering. The assessment of this is necessarily multidisciplinary.  相似文献   

11.
气候资源是影响动物行为、发育、存活、繁殖与分布等的重要因子。为了探明广西邦亮东黑冠长臂猿栖息地的气候环境特征,对其栖息地附近县(乡)的主要气象要素进行统计与分析。结果表明:广西邦亮东黑冠长臂猿栖息地年均日照时数为1 521.8小时,月变幅为25.44%;年均气温为19.1℃,最冷月平均气温为11.0℃,最热月平均气温为25.0℃;年均降雨量为1 606.3 mm,月变幅为86.05%;年均蒸发量为1 507.1 mm,月变幅为28.06%;年均相对湿度为80%,月变幅为2.60%;年均风速为1.5 m/s,月变幅为15.4%。  相似文献   

12.
Pesticides are a well-known family of chemicals that have contaminated water systems globally. Four common subfamilies of pesticides include organochlorines, organophosphates, pyrethroids, and carbamate insecticides which have been shown to adversely affect the human nervous system. Studies have shown a link between pesticide exposure and decreased viability, proliferation, migration, and differentiation of murine neural stem cells. Besides human exposure directly through water systems, additional factors such as pesticide bioaccumulation, biomagnification and potential synergism due to co-exposure to other environmental contaminants must be considered. A possible avenue to investigate the molecular mechanisms and biomolecules impacted by the various classes of pesticides includes the field of -omics. Discovery of the precise molecular mechanisms behind pesticide-mediated neurodegenerative disorders may facilitate development of targeted therapeutics. Likewise, discovery of pesticide biodegradation pathways may enable novel approaches for water system bioremediation using genetically engineered microorganisms. In this mini-review, we discuss recently established harmful impacts of various categories of pesticides on the nervous system and the application of -omics field for discovery, validation, and mitigation of pesticide neurotoxicity.  相似文献   

13.
The goal of this research was to learn about the level of knowledge in Polish industrial organizations about the principles of cleaner production and also to identify some barriers to implementation of cleaner production strategies. In order to gain this information, a special questionnaire with fundamental questions related to environmental attitudes was distributed to various Polish enterprises. The purpose of this paper is to attempt to characterize the state of cleaner production in Poland based on the results of this survey.  相似文献   

14.
'Molecular farming' is the production of valuable recombinant proteins in transgenic organisms on an agricultural scale. While plants have long been used as a source of medicinal compounds, molecular farming represents a novel source of molecular medicines, such as plasma proteins, enzymes, growth factors, vaccines and recombinant antibodies, whose medical benefits are understood at a molecular level. Until recently, the broad use of molecular medicines was limited because of the difficulty in producing these proteins outside animals or animal cell culture. The application of molecular biology and plant biotechnology in the 1990s showed that many molecular medicines or vaccines could be synthesised in plants and this technology is termed 'molecular farming'. It results in pharmaceuticals that are safer, easier to produce and less expensive than those produced in animals or microbial culture. An advantage of molecular farming lies in the ability to perform protein production on a massive scale using hectares of cultivated plants. These plants can then be harvested and transported using the agricultural infrastructure. Thus, molecular farming allows rapid progress from genetic engineering to crop production, and new cash crops producing recombinant proteins are already being commercially exploited. We speculate that as functional genomics teaches us more about the nature of disease, molecular farming will produce many of the protein therapeutics that can remedy it.  相似文献   

15.
利用克氏螯虾触角电位监测水体Hg2+污染的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
随着工业的发展,水体污染日趋严重。一定量的重金属对生物体和人体的生理生化功能具有多方面的毒性作用。水环境中高浓度的Hg2+对生物的危害极大,无机汞中又以HgCl2为最。在水污染生物监测的研究领域内,国外已有用螯虾作为实验动物的报道。然而,迄今尚未见有Hg2+影响淡水螯虾触角感觉功能的报道。  相似文献   

16.
利用克氏螯虾触角电位监测水体Hg~(2+)污染的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
随着工业的发展,水体污染日趋严重。一定量的重金属对生物体和人体的生理生化功能具有多方面的毒性作用。水环境中高浓度的Hg~(2+)对生物的危害极大,无机汞中又以HgCl_2为最。在水污染生物监测的研究领域内,国外已有用螯虾作为实验动物的报道。然而,迄今尚未见有Hg~(2+)影响淡水螯虾触角感觉功能的报道。  相似文献   

17.
In order to develop a sound biotechnique for monitoring water quality that builds on the previous experiments carried out in our laboratory, a specific D. magna clone C1242 was used to study the effects of pollutants on phototactic behavior, in all experiments, the animals showed a stable and repeatable phototactic index approximated 0.2 in the presence and 0.4 in the absence of fish kairomenes, which decreased significantly in response to pollutants. There existed no pollutant x fish kairomone interaction, indicating the changes in phototactic behavior of animals imposed by pollutants were independent of the presence of fish kairomones. The detection limits for changes in phototactic behavior of D. magna clone C1 242 are 0.04 mg/L for copper, 0.02 mg/L for cadmium, and 0.80 mg/L for PCP, respectively, quite lowerthan LC50(48 h). The changes in phototactic behavior in presence to pollutants occurred quickly(3 h) compared to the period over whole acute toxicity tests. Therefore, D. magna clone C1 242 could be potentially used to monitor water quality. Moreover, the phototactic behavior did not decrease further in the pollutant mixtures employed in our experiments compared to individual pollutants, except in the Cd-PCP Lre.atme~t.This fact suggests that the formation of water quality criteria must be based upon pollutant mixture tests.Keywords: Daphnia; phototactic behavior; copper; cadmium; pentachlorophenol; fish kairomenes  相似文献   

18.
藏北高原自然资源的利用与保护   总被引:3,自引:0,他引:3  
藏北高原面积约60万km2,海拔在4500m以上,为青藏高原的主体。其气候寒冷干燥,人迹稀少,以高寒草原为主的生态系统基本保存完好,其天然草地辽阔,各类可利用草地面积占土地总面积53%,为西藏最大牧区,适宜发展地毯毛羊--藏绵羊。这里栖居着许多青藏高原特有的国家一、二类保护动物及有一定经济价值动物资源。高原上湖泊众多,湖泊面积占全国湖泊总面积的1/4以上。其中许多盐湖盛产有工业开采价值的食盐、天然碱及硼、锂、钾等重要稀有元素,为我国主要矿盐产地和远景开发区。目前因草地生态脆弱和利用不当,已有4%草地退化,沙地面积扩大,野生动物栖居范围也趋缩小;少数盐矿产地环境有所污染,盐湖资源浪费较大。所以适度利用天然草地、保护野生动物和综合开发盐湖资源,防止自然生态环境的恶化乃是开发藏北高原生物矿产资源的重要战略措施。  相似文献   

19.
金属材料的微生物腐蚀与防护研究进展   总被引:5,自引:1,他引:4  
探讨了金属材料在微生物作用过程中的腐蚀与防护。通过在实验室内构建微生物环境来模拟自然状态下金属材料的腐蚀行为。回溯了微生物腐蚀的研究历史,结合近年来的研究进展,重点阐述了生物膜在金属腐蚀过程中的特性,并针对滨海工业用循环冷却水系统中金属材料的MIC,介绍了相关的防腐蚀技术并展望了未来的发展趋势。自然海水中,微生物倾向于附着在材料表面形成生物膜,它在金属/溶液界面扮演着双重角色。金属的微生物腐蚀通常由多种微生物协同作用,具有复杂的作用机制,应该综合运用各种物理、化学手段,尤其是防护性涂层方法才能达到控制腐蚀的目的。  相似文献   

20.
铊(Tl)是典型的毒害重金属元素之一,对生物体的毒性高于Hg、Cd和Pb等元素。铊在天然水环境相关介质中的背景含量较低,但可通过各种工业活动大量进入水体环境,借由水体迅速迁移扩散,对生态系统造成巨大的环境隐患。本文总结了铊在水体中的分布特征,并重点阐述了铊在矿物胶体和天然有机质(腐殖酸)等界面上迁移转化行为的研究进展。研究表明,铁(氢)氧化物、锰(氢)氧化物均能在一定程度上吸附水体中的Tl(I),铊在一些锰(氢)氧化物表面的吸附行为可能会涉及Tl(I)在矿物表面的氧化还原机制。矿物表面对铊离子的吸附作用不仅与矿物的组成成分有关,还可能与矿物组成成分的晶型结构密切相关。天然有机质对铊迁移转化影响作用的研究目前主要偏重天然腐殖酸对铊的络合作用。因此,要加强的研究铊分别在不同种类、不同晶型的矿物和不同类型的天然有机质界面上的迁移转化行为,并借助高精度的价态和结构分析手段从分子水平上探讨其迁移转化机理。了解铊在水体中的迁移转化有助于深入认识铊的环境地球化学行为,并为研究铊的污染治理提供理论基础。  相似文献   

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