Graft-specific inhibition of complement activation after xenotransplantation; genetically modified pig organs versus systemic anticomplement strategies.
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Animals↗
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Results for “Organisms, Genetically Modified”
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Substantial equivalence of antinutrients and inherent plant toxins in genetically modified novel foods.
For a safety evaluation of foodstuff derived from genetically modified crops, the concept of the substantial equivalence of modified organisms with their parental lines is used following an environmental safety evaluation. To assess the potential pleiotropic effect of genetic modifications on constituents of modified crops data from US and EC documents were investigated with regard to inherent plant toxins and antinutrients. Analysed were documents of rape (glucosinolates, phytate), maize (phytate), tomato (tomatine, solanine, chaconine, lectins, oxalate), potato (solanine, chaconine, protease-inhibitors, phenols) and soybean (protease-inhibitors, lectins, isoflavones, phytate). In several documents used for notifications no declarations even on essential inherent plant toxins and antinutrients could be found, for instance data on phytate in modified maize were provided only in one of four documents. Significant variations in the contents of these compounds in parental and modified plants especially due to environmental influences were observed: drought stress, for example, was made responsible for significantly increased glucosinolate levels of up to 72.6micromol/g meal in modified and parental rape plants in field trials compared to recommended standard concentrations of less than 30micromol/g. Taking into account these wide natural variations generally the concentrations of inherent plant toxins and antinutrients in modified products were in the range of the concentrations in parental organisms. The results presented indicate that the concept of the substantial equivalence is useful for the risk assessment of genetically modified organisms (GMOs) used for novel foods but possible environmental influences on constituents of modified crops need more attention. Consistent guidelines, specifying data of relevant compounds which have to be provided for notification documents of specific organisms have to be established. Because of the importance of inherent plant toxins and antinutrients on nutritional safety, also coherent databases of standard parental lines and clear criteria for mandatory declarations are necessary.
Crops, Agricultural↗
Quantification of genetically modified soybeans using a combination of a capillary-type real-time PCR system and a plasmid reference standard.
Because the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved genetically modified varieties in many countries, there is a need for a rapid and useful method of GMO quantification in food samples. In this study, a rapid detection system was developed for Roundup Ready Soybean (RRS) quantification using a combination of a capillary-type real-time PCR system, a LightCycler real-time PCR system, and plasmid DNA as the reference standard. In addition, we showed for the first time that the plasmid and genomic DNA should be similar in the established detection system because the PCR efficiencies of using plasmid DNA and using genomic DNA were not significantly different. The conversion factor (Cf) to calculate RRS content (%) was further determined from the average value analyzed in three laboratories. The accuracy and reproducibility of this system for RRS quantification at a level of 5.0% were within a range from 4.46 to 5.07% for RRS content and within a range from 2.0% to 7.0% for the relative standard deviation (RSD) value, respectively. This system rapidly monitored the labeling system and had allowable levels of accuracy and precision.
Food, Genetically Modified↗
Genes, genome and Gestalt.
According to Gestalt thinking, biological systems cannot be viewed as the sum of their elements, but as processes of the whole. To understand organisms we must start from the whole, observing how the various parts are related. In genetics, we must observe the genome over and above the sum of its genes. Either loss or addition of one gene in a genome can change the function of the organism. Genomes are organized in networks of genes, which need to be well integrated. In the case of genetically modified organisms (GMOs), for example, soybeans, rats, Anopheles mosquitoes, and pigs, the insertion of an exogenous gene into a receptive organism generally causes disturbance in the networks, resulting in the breakdown of gene interactions. In these cases, genetic modification increased the genetic load of the GMO and consequently decreased its adaptability (fitness). Therefore, it is hard to claim that the production of such organisms with an increased genetic load does not have ethical implications.
Animals↗
[The zig-zagging legislative policies of the European Union in relation to transgenic products].
The author analyses the E.U. legislative policies related to transgenic products from the 80s until nowadays, she stops in Directive 2001/18/Ce and its conversion into national law. She explains how the regulatory frame is after the recent approval of the newest rules about tracking and labelling genetically modified organisms (OMG). She also studies communitary jurisprudence about this subject according to the legislation, concretely sentence 9 September 2003 in the affair C-236/01 about commercialisation of two lines of transgenic corn. Finally she points out how legislative policies have influenced the creation and development of biotechnological enterprises.
Animals↗
Functional dynamics of living systems and genetic engineering.
The discussion on Genetically Modified Organisms (GMO's) has been centred mainly on the nature and effects on economy, human health, environment, of the few transgenic plant lines present in the market in the last eight years. On the contrary, the present paper starts with a discussion of some of the relevant changes in our basic knowledge of the structure and dynamics of living systems in the last twenty years. Contemporary Biology is then compared with what may be called the "modern paradigm" of life sciences on which present day GMO's are conceptually based. Technical, environmental, social and economic problems deriving from the unexpected, persistent prevalence of the old fashioned modern vision of life in the "spirit of time" will be thoroughly discussed with a particular attention to the virtualisation process of GMO's and the effects of the prevalence over economic, social, environmental reality of their symbolic values.
Animals↗
[Transgenics and controlled evolution].
Mutation events are responsible for the generation of genetic variability in the populations enabling the occurrence of natural selection which favors the better-adapted types. The exploitation of this variability, though carried out empirically, dates from ten thousand years ago with the domestication of the first cultivated crops. With the advent of genetics, rational selection procedures were adopted with a view of the genetic breeding of plants, animals and microorganisms which might be of interest to men. Recently, new DNA manipulation techniques came up enabling the transference of genes between organisms, cutting across barriers which hindered crossing between the vegetable, animal, protist and fungus kingdoms. The generation of genetically modified organisms, or transgenics, has aroused a heated and controversial debate in various sectors of our society. Yet we must be cautious before generalizing the use of transgenics since each one should be analyzed at a time for its particular advantages and drawbacks, and for its contribution to the improvement of life quality. This paper also considers recent methods of mutation and in vitro genic recombination.
Biological Evolution↗
Modeling the invasion of recessive Bt-resistant insects: an impact on transgenic plants.
There is a growing public concern on ecological and evolutionary consequence of the use of genetically modified organisms. We study the impact of Bt-resistant pests on genetically modified Bt crops. We develop and analyse a conceptual reaction-diffusion model of the Bt crop-Bt-susceptible insects-Bt-resistant insects to simulate the invasion of Bt-resistant insects. We show by means of computer simulations that there is a key parameter, which we define as the growth number that characterizes the insects' fitness. We also show that the Bt-resistant insect invasion can lead to inhomogeneity in plant and insect spatial distributions. The plant biomass is found to be essentially dependent on the duration of the Bt-resistant insect reproduction period. There are two types of this dependence. One of them exhibits, respectively, higher plant biomass in comparison with another. The ambiguity in the response of the Bt crop-Bt-susceptible insects system to the invasion of Bt-resistant insects can lead to serious complications in attempts to regulate the dynamics of the system.
Animals↗
The Developing Country Reactions to Biomedical Techniques and Plant Biotechnology: The Tunisian Experience.
In the present study we present the conditions offered to biotechnology development in Tunisia and we compare three main biotechnology applications which raise ethical and health problems: organ transplant, assisted reproductive techniques, and genetically modified organisms. We try to identify factors that have allowed success of the first two applications and failure of the latter. Conditions offered to biotechnology in other African countries are also discussed.
Journal Article↗
Real-time detection of genetically modified soya using Lightcycler and ABI 7700 platforms with TaqMan, Scorpion, and SYBR Green I chemistries.
A comparative cross platform evaluation of real-time polymerase chain reaction detection of DNA sequences present in Roundup Ready soya was undertaken using the ABI 7700 and Roche Lightcycler detection systems in combination with 3 different detection chemistries: TaqMan, Scorpion primers, and SYBR Green I fluorescent dye. Various copy numbers of a plasmid containing the soya lectin sequence were used to determine the sensitivity and reproducibility of the different technology combinations and to examine both inter and intra machine variability. To examine the relative accuracy of each technology, the genetically modified soya content of baked products containing known amounts of Roundup Ready soya was determined by detection of lectin and the EPSPS transgene. It was determined that the combination of TaqMan detection chemistry and the ABI 7700 platform represented the best method for quantitative detection of genetically modified organisms in terms of both precision and accuracy.
Analysis of Variance↗
[The critical scientists' voice].
The intricate debate over genetically modified organisms (GMOs) involves powerful economic interests, as well as ethical, legal, emotional and scientific aspects, some of which are dealt with in this paper.(It is possible to identify two main groups of scientists across the GMOs divide: the triumphalist and the critical group.) Scientists in the triumphalist group state that GMOs and their derivatives are safe for the environment and do not offer health hazards any more than similar, non-genetically modified, products. This view is disputed by the critical scientists, who are prompted by the scarcity of studies on the environmental impacts and toxicity of GMOs, and who point out flaws in tests performed by the same companies which hold the patents. They are also critical of the current state of the process of gene transference, lacking accuracy, a fact which, coupled with the scant knowledge available about 97% of the genome functions, may produce unforseeable effects with risks for the environment and public health yet to be assessed. Examples of such effects are: the transference of alien genes [??] to other species, the emergence of toxins, the creation of new viruses, the impacts on beneficial insects and on biodiversity in general.
Bioethical Issues↗
Biological substitutes for pesticides.
In the 20th century an increasing number of pesticides, based on biocidal molecules, were the means for a substantial increase in food and fibre production and quality. Because of health and environmental concerns continued extensive use of such molecules is intensively debated and substitutes are often urgently required. Beside crop plant resistance, various biological control methods based on natural pest suppressing organisms are regarded as main alternatives. Several approaches and concepts also have been tested and commercial organism-based preparations are steadily increasing. However, further biotechnological efforts are required to give them status of being practical substitutes to pesticides. At present they are not comparable to pesticides in meeting efficacy, market and other expectations, but they still have a promising future, especially where genetically modified organisms can be used.
Agriculture↗
[Animal models for assessment of GMO allergenicity: advantages and limitations].
Incidence of IgE-mediated allergic reactions to foods is increasing as well as the severity of associated symptoms and numerous foods are now incriminated, probably in relation with modifications of dietary habits and increased exposure to new or modified food ingredients. Therefore, the introduction on the market of food composed of or derived from genetically modified organisms (GMOs) raised the question of their potential allergenicity. Particularly with regards to the allergenicity of a newly expressed protein, it is necessary to obtain, from several steps in the risk assessment process, a cumulative body of evidence which minimises any uncertainty. This may include the use of animal model despite no fully reliable validated model is available yet. Such animal models should allow to address 3 major issues: Is the novel protein a sensitizer, i.e. does it possess intrinsic properties that allow to sensitize a predisposed individual? Is the protein an elicitor i.e. is it able to elicit an allergic reaction in a sensitised individual? And is the protein an adjuvant, i.e. can it facilitate or enhance the sensitisation to an other protein? Animal models under investigation currently include mice, rats and guinea pigs but models such as dogs and swine also appeared a few years ago. The aim is to mimic the mechanism and characteristics of the sensitisation phase and/or the elicitation phase of the allergic reaction as it occurs in atopic humans. They are necessary because sensitisation studies can obviously not be done in human and because in vitro tests cannot reproduce the complexity of the immune system. We propose a mouse model which mimics both phases of the allergic reaction. It has permitted to evidence that biochemical and clinical manifestations occuring during the active phases of the allergic reaction differ according to the structure of the allergen used for the challenge. This may allow to compare the allergenic potential of a genetically modified protein with that of the conventional one and to identify possible unintended effects. However, pathogenesis of food allergy in human is very complex and multifactorial, including individual differences in susceptibility, environmental factors, conditions of exposure, ... No animal model can take into account all these factors and allow a reliable prediction of the prevalence and severity of allergic reactions which would result from the exposure to a (novel) protein. Nevertheless, point by point analysis using the different models available may provide useful informations on the potential allergenicity of a novel protein.
Adjuvants, Immunologic↗
Future of plant science in Zimbabwe.
Zimbabwe's agricultural biotechnology research capacity is located at universities, government research institutions and parastatal (state funded) organizations. Projects range from those using traditional biotechnology to a few that are experimenting with genetically modified organisms (GMOs).
Agriculture↗
Xenotransplantation: perspectives from The Netherlands.
Recently, the Health Council of the Netherlands published a report on xenotransplantation. The technique is considered ethically acceptable, both from a human and from an animal point of view. Clinical application should not yet be permitted, however, because of continuing rejection problems and growing concerns on safety aspects associated with possible transfer of pathogens from the xenotransplant to the host. More research is necessary. Mainly because of the risk for infection, nonhuman primates are not considered acceptable as source animals; the genetically engineered pig is at present the source animal of choice. Legally, import in the Netherlands of (organs from) source animals from within Europe is difficult to prevent. Therefore experiments with such material are not subjected to licensing by the government, which is the case for experiments involving genetic engineering with animals in the Netherlands, but only by local review boards. This situation is considered unwanted and adjustment of the pertinent law is suggested. Also, both genetically engineered animals and patients carrying organs from such animals fall under the European Genetically Modified Organisms regulations. These regulations are not designed for this case and conflicts may arise. Agreements on how to handle this situation have to be made at the European level. It is proposed to draft a national law on "biologicals," medical products consisting at least partly of living materials. Pending such regulations, it is suggested, also on a European level, that xenotransplants be considered as medicines, which would allow adequate control of safety aspects.
Animals↗
Proposals for the future regulation of biotechnology in Australia.
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Advisory Committees↗
Opposite enantioselectivities of two phenotypically and genotypically similar strains of Pseudomonas frederiksbergensis in bacterial whole-cell sulfoxidation.
Soil samples were screened to select microorganisms with the capability to oxidize organic sulfides into the corresponding sulfoxides with differential enantioselectivities. Several bacterial strains that preferentially produced the S-configured sulfoxide enantiomer were isolated. Surprisingly, one bacterial strain, genotypically and phenotypically characterized as Pseudomonas frederiksbergensis, selectively gave the R enantiomer. The finding that two apparently identical organisms displayed opposite enantioselectivities is novel for non-genetically modified organisms.
DNA, Bacterial↗
Detection of transgenes in soybean via a polymerase chain reaction and a simple bioluminometric assay based on a universal aequorin-labeled oligonucleotide probe.
The recombinant photoprotein aequorin was used as a reporter in highly sensitive and automatable hybridization assays for the analysis of transgenic sequences in genetically modified organisms (GMO). The terminator of the nopaline synthase gene (NOS) from Agrobacterium tumefaciens and the 35S promoter sequence were detected in genetically modified soybean. The endogenous, soybean-specific, lectin gene was also detected for confirmation of the integrity of extracted DNA. A universal detection reagent was produced through conjugation of aequorin to the oligonucleotide (dA)(30). Biotinylated (through PCR) products for the three target sequences were captured onto streptavidin-coated wells, and one strand was removed by NaOH treatment. The immobilized single-stranded DNAs were then hybridized with oligonucleotide probes consisting of a target-specific segment and a poly(dT) tail. This allowed the subsequent determination of all hybrids through the use of the (dA)(30)-aequorin conjugate as a universal reagent. The bound aequorin was measured by adding Ca(2+) and integrating the light emission for 3 s. As low as 2 pM (100 amol per well) of amplified DNA was detectable for all three targets, with a signal-to-background ratio of about 2. The analytical range extended up to 2000 pM. As low as 0.05% GMO content in soybean can be detected with a signal-to-background ratio of 8.2. The overall repeatability of the proposed assay, including DNA extraction, PCR, and hybridization assay, ranged from 7.5-19.8%. The use of a (dA)(30)-aequorin conjugate renders the assay configuration general for any target DNA, provided that the specific probe carries a poly(dT) tail.
Aequorin↗