Genetically Engineered Crops

Previous research on the vasculature of tumor-bearing animals has focused upon the microvasculature. Magnetic resonance angiography (MRA) offers a noninvasive, complementary approach that provides information about larger vessels. Quantitative analysis of MRA images of spontaneous preclinical tumor models has not been previously reported. Eleven TgT 121 ;p53 +/-mice, which invariably develop choroid plexus carcinoma (CPC), and nine age-matched healthy controls were imaged using T1, T2, and a high-resolution 3D time-of-flight (TOF) MRA sequences at 3T. Tumors and vessels were segmented to determine tumor volume and vascular attributes, including number of terminal branches (TBC), vessel count (VC), and the average vessel radii (AVRAD) of MRA-visible vessels within the tumor. Differences in the vasculature between tumor-bearing animals and healthy controls were analyzed statistically. Although the spatial resolution of MRA prohibits visualization of capillaries, a high density of intra-tumor blood vessels was visualized in CPC mice. A significant increase in TBC and VC, but not AVRAD, was observed in CPCs when compared to normal controls. Both TBC and VC were highly correlated with tumor volume. This study represents the first MRA analysis of a spontaneous preclinical brain tumor model. Although the spatial resolution of MRA is less than histological analysis, MRA-obtained vascular attributes provide useful information with full brain coverage. We show that consistent tumor vasculature properties can be determined by MRA. Such methods are critical for developing preclinical therapeutic testing and will help guide the development of human brain tumor analyses.

There is much discussion of the probability of transgene flow from transgenic crop varieties to landraces and wild relatives in centers of origin or diversity, and its genetic, ecological, and social consequences. Without costly research on the variables determining gene flow, research on transgene frequencies in landrace (or wild relative) populations can be valuable for understanding transgene flow and its effects. Minimal research requirements include (1) understanding how farmer practices and seed systems affect landrace populations, (2) sampling to optimize N e /n (effective /census population size), (3) minimizing variance at all levels sampled, and (4) using N e to calculate binomial probabilities for transgene frequencies. A key case is maize in Mexico. Two peer-reviewed papers, based on landrace samples from the Sierra Juárez region of Oaxaca, Mexico, reached seemingly conflicting conclusions: transgenes are present (

Intraoperative assessment of surgical margins is critical to ensuring residual tumor does not remain in a patient. Previously, we developed a fluorescence structured illumination microscope (SIM) system with a single-shot field of view (FOV) of 2.1×1.6 mm (3.4 mm2) and sub-cellular resolution (4.4 μm). The goal of this study was to test the utility of this technology for the detection of residual disease in a genetically engineered mouse model of sarcoma. Primary soft tissue sarcomas were generated in the hindlimb and after the tumor was surgically removed, the relevant margin was stained with acridine orange (AO), a vital stain that brightly stains cell nuclei and fibrous tissues. The tissues were imaged with the SIM system with the primary goal of visualizing fluorescent features from tumor nuclei. Given the heterogeneity of the background tissue (presence of adipose tissue and muscle), an algorithm known as maximally stable extremal regions (MSER) was optimized and applied to the...

Rapid detection of bacterial presence on implantable medical devices is essential to prevent biofilm formation, which consists of densely packed bacteria colonies able to withstand antibiotic-mediated killing. In this work, a smart approach is presented to integrate electrochemical sensors for detecting bacterial infections in biomedical implants made of isotactic polypropylene (i-PP) using chemical assembly. The electrochemical detection is based on the capacity of conducting polymers (CPs) to detect extracellular nicotinamide adenine dinucleotide (NADH) released from cellular respiration of bacteria, which allows distinguishing prokaryotic from eukaryotic cells. Oxygen plasma-functionalized free-standing i-PP, coated with a layer (˜1.1 µm in thickness) of CP nanoparticles obtained by oxidative polymerization, is used as working electrode for the anodic polymerization of a second CP layer (˜8.2 µm in thickness), which provides very high electrochemical activity and stability. The r...

The European Food Safety Authority (EFSA) asked the Panel on Genetically Modified Organisms to establish a self-tasking Working Group with the aim of (1) producing a scientific review of the current guidance of the GMO Panel for Environmental Risk Assessment (ERA), focusing on the potential impacts of GM plants on Non-Target Organisms (NTOs), (2) proposing criteria for NTOs selection, and (3) providing advise on standardized testing methodology. This initiative was undertaken in response to a need and request from a wide range of stakeholders, including the European Commission and Member States. In first instance, the self-tasking Working Group on Non-Target Organisms (EFSA NTO WG) mainly considered impacts of GM plants on invertebrate species, but also took account of ecosystem functions that could be altered. The EFSA NTO WG considered the necessity for clear and objective protection goals, for which assessment and measurement endpoints shall be developed; the need to initiate the scientific risk assessment by setting testable hypotheses; criteria for appropriate selection of test species and ecological functional groups; appropriate laboratory and field studies to collect relevant NTO data; and the use of statistical techniques that should be an integral part of experimental design. The EFSA NTO WG considered the range of approaches and methodologies of ERA of NTOs as described in the current literature and proposed risk assessment approaches based on selection of functional groups and individual species within a tiered approach. The present scientific opinion provides guidance to risk assessors for assessing potential effects of GM plants on NTOs, together with rationale for data requirements in order to complete a comprehensive ERA for NTOs. In this respect, guidance to applicants as outlined in the present opinion has been inserted in the updated Guidance Document of the EFSA GMO Panel for the ERA of GM plants.

Evolution of resistance by pests has diminished the efficacy of transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt). In China, where transgenic cotton producing Bt toxin Cry1Ac has been planted since 1997, field control failures have not been reported but the frequency of resistance to Cry1Ac has increased in the cotton bollworm, Helicoverpa armigera. This provides incentive to switch to multi-toxin Bt cotton, which is grown in many other countries. Previous work created four laboratory strains of H. armigera with >100-fold resistance to Cry1Ac, with the genetic basis of resistance known in all but the LF256 strain. Here, we analyzed the genetic basis of resistance in Cry1Ac in LF256 and evaluated cross-resistance of all four strains to three toxins produced by widely planted multi-toxin Bt cotton: Cry1Fa, Cry2Ab, and Vip3Aa. DNA sequencing revealed that LF256 lacked the mutations in three genes (HaTSPAN1, HaABCC2, and HaABCC3) that confer resistance to Cry1Ac in two other strains of H. armigera we analyzed. Together with previous results, the data reported here show that each of the four strains examined has a different genetic basis of resistance to Cry1Ac. Significant positive cross-resistance occurred to Cry1Fa in three of the four strains tested but not to Cry2Ab or Vip3Aa in any strain. Thus, Cry2Ab and Vip3Aa are likely to be especially valuable for increasing the efficacy and durability of Bt cotton against H. armigera populations that have some resistance to Cry1Ac.

Despite the fundamental contribution of the gut microbiota to host physiology, the extent of its variation in genetically-identical animals used in research is not known. We report significant divergence in both the composition and metabolism of gut microbiota in genetically-identical adult C57BL/6 mice housed in separate controlled units within a single commercial production facility. The reported divergence in gut microbiota has the potential to confound experimental studies using mammalian models. esearchers using animal models are becoming increasingly aware of possible influences of the gut microbiota on physiology. Murine models have been used to demonstrate relationships between the gut microbiota and obesity 1 , metabolic disease 2 , cardiovascular health 3 , nervous system development 4 , diabetes 5 , and immune function 6 , hepatic function 7 , inflammatory bowel conditions 8 , and carcinogenesis 9 , highlighting the potential impact that differences in the microbiome of mice from different animal facilities could have on research. However, most researchers assume that genetically-identical mice derived from a single supplier will have an equivalent microbiome. To test this assumption we studied the faecal microbiome and metabolome of genetically-identical C57BL/6 mice housed in four separate controlled units within a single facility of a commercial supplier of animals for research. Faecal samples were collected at eight weeks of age from twenty mice, with five mice sampled in each of four barrier rooms. These mice were separated by no more than ten generations. Murine faecal samples. Faeces were collected from eight week old C57BL/6 at the Charles River commercial facility (Margate, UK) under commercial licence, with all mice kept in accordance with protocols approved by The Animal Health and Welfare Board for England. Samples were collected from 20 mice, housed in four separate barrier rooms within the facility, fed the same chow (a VRF1 diet, SDS). The five mice sampled in each room were housed in separate cages. The five mice from each of the four rooms were taken from separate cages i.e. no two mice came from the same cage. Mice in this study were handled by individuals wearing gloves for cage cleaning purposes on a weekly basis. Mice were not housed exclusively with litter mates, with 27 individuals housed per room. Samples consisted of individual faecal pellets taken from individual mice. After collection, pellets were placed into separate collection tubes and frozen prior to analysis. Microbiota. Nucleic acid extractions were carried out using a combination of physical disruption and phenol/chloroform extraction methods, described previously 10 . 16S rRNA gene universal Bacterial primers 27F-519R (27F 59-AGRGTTTGATCMTGGCTCAG, 519R 59-GTNTTACNGCGGCKGCTG) were used in a single-step 30 cycle PCR using HotStarTaq Plus Master Mix Kit (Qiagen, Valencia, CA) performed under the following conditions: 94oC for 5 minutes, followed by 28 cycles of: 94oC for 30 seconds, 53oC for 40 seconds, and 72oC for 1 minute. Amplification was followed by a final elongation step at 72oC for 5 minutes. Following PCR, all amplicon products from different samples were mixed in equal concentrations and purified using Agencourt Ampure beads (Agencourt Bioscience Corporation, MA, USA). Samples were sequenced utilizing Roche 454 FLX titanium instruments and reagents following manufacturer's guidelines. A total of 165,934 16S rRNA gene sequences were obtained from the 20 faecal sample extracts. Following curation, an average of 4,356 sequences was obtained for each of the samples. For analysis of alpha and beta diversity, samples were normalised to 2,179 sequences per sample. Sequence data analysis was carried out. Here, the Q25 sequence data derived from the sequencing process was processed using standard analysis pipeline processes (MR DNA, Shallowater, USA). Sequences were depleted of barcodes and primers then short sequences ,200 bp removed, as were sequences with ambiguous base calls removed, and sequences with homopolymer runs exceeding 6 bp, sequences were denoised and chimeras removed . Operational taxonomic units were defined after removal of singleton sequences, clustering at 3% divergence (97% similarity). Final OTUs were taxonomically classified using BLASTn against a curated databased derived from GreenGenes, NCBI and RDP databases . Normalized and de-noised files were then rarefied and run through QIIME to generate alpha and beta diversity data. Additional statistical analyses were performed with NCSS2007 (NCSS, UT) and XLstat 2012 (Addinsoft, NY).

Mitogillin and the related fungal ribotoxins are highly specific ribonucleases which inactivate the ribosome enzymatically by cleaving the 23–28 S RNA of the large ribosomal subunit at a single phosphodiester bond. The site of cleavage occurs between G4325 and A4326 (rat ribosome numbering) which are present in one of the most conserved sequences (the α-sarcin loop) among the large subunit ribosomal RNAs of all living species. Amino acid sequence comparison of ribotoxins and guanyl/purine ribonucleases have identified domains or residues likely involved in ribonucleolytic activity or cleavage specificity. Fifteen deletion mutants (each 4 to 8 amino acid deletions) in motifs of mitogillin showing little amino acid sequence homology with guanyl/purine ribonucleases were constructed by site-directed mutagenesis. Analyses of the purified mutant proteins identified those regions in fungal ribotoxins contributing to ribosome targeting and modulating the catalytic activity of the toxin; so...

Given the uncertainty of the use of genetic engineering in pro- duction of genetically modified (GM) foods, it remains the sub- ject of one of the most vitriolic scientific debates throughout the globe. Newer facets of the debate include regulation of GM seed labeling as well as liability pertaining to GM pollen spread to non-GM plants. This study analyzes Vermonter

Many traditional vaccines have proven to be incapable of controlling newly emerging infectious diseases. They have also achieved limited success in the fight against a variety of human cancers. Thus, innovative vaccine strategies are highly needed to overcome the global burden of these diseases. Advances in molecular biology and reverse genetics have completely restructured the concept of vaccinology, leading to the emergence of state-of-the-art technologies for vaccine design, development and delivery. Among these modern vaccine technologies are the recombinant viral vectored vaccines, which are known for their incredible specificity in antigen delivery as well as the induction of robust immune responses in the vaccinated hosts. Although a number of viruses have been used as vaccine vectors, genetically engineered Newcastle disease virus (NDV) possesses some useful attributes that make it a preferable candidate for vectoring vaccine antigens. Here, we review the molecular biology o...

In recent years a number of beneficial health effects have been ascribed to the renin-angiotensin system (RAS) that extend beyond lowering blood pressure, primarily mediated via the angiotensin-converting enzyme-2 (ACE2)/angiotensin (1–7) or Ang(1–7)/MAS receptor axis. Moreover, once thought as merely a systemic effector, RAS components exist within tissues. The highest tissue concentrations of ACE2 mRNA are located in the gut making it an important target for altering RAS function. Indeed, genetically engineered recombinant probiotics are promising treatment strategies offering delivery of therapeutic proteins with precision. An Ang(1–7) secreting Lactobacillus paracasei (LP) or LP-A has been described for regulation of diabetes and hypertension; however, we are the first to the best of our knowledge to propose this paradigm as it relates to aging. In this Research Practice manuscript, we provide proof of concept for using this technology in a well-characterized rodent model of agi...

Flavonoids are significant secondary metabolites of vascular plants. They have been proven to possess numerous types of anti-bacterial, anti-tumor, anti-oxidant and anti-inflammatory bioactivities etc. Thereby, there are many flavonoids extracted and purified from plants and have been used for biological tests. Nevertheless, the traditional extraction methods require a large amount of initial sample, tedious and professional techniques and low yield of target compound. Until present, the advanced development of genetic engineerings and recombinant protein as platform allow synthesis of high amount of different types of flavoid in short time. Escherichia coli is one of the most popular host for whole-cell biotransformation of flavonoids and their derivatives due to its simple genetical, physiological system and fast growth. In this paper, we described the biosynthetic method of morin-3-O-rhamnopyranoside from a genetically engineered E. coli using morin as substrate. In particular, t...

In the mid-1990s, new banana planting material was introduced into Tanzania in response to increased pest and disease pressures on banana production and the high levels of susceptibility of local endemic varieties, coupled with a lack of chemical inputs to combat these constraints. The formal introduction of new hybrid bananas into the region began in 1997 with the efforts of the Kagera Community Development Program (KCDP). The goal of the program was to increase farmers’ food and income security by improving banana productivity. About a dozen new banana varieties were introduced to the Kagera region of Tanzania. Among them were the first banana hybrids, bred by the Fundación Hondureña de Investigación Agrícola (FHIA). New planting material was disseminated to farmers by KCDP and government extension agents through trials, demonstrations, and “mother gardens.” In particular, farmers themselves played a major role in diffusing new planting material, as they have historically done in ...

Organotypic culture systems from disease-specific induced pluripotent stem cells (iPSCs) exhibit obvious advantages compared with immortalized cell lines and primary cell cultures, but implementation of iPSC-based high-throughput (HT) assays is still technically challenging. Here, we demonstrate the development and conduction of an organotypic HT Cl À /I À exchange assay using cystic fibrosis (CF) disease-specific iPSCs. The introduction of a halide-sensitive YFP variant enabled automated quantitative measurement of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) function in iPSC-derived intestinal epithelia. CFTR function was partially rescued by treatment with VX-770 and VX-809, and seamless gene correction of the p.Phe508del mutation resulted in full restoration of CFTR function. The identification of a series of validated primary hits that improve the function of p.Phe508del CFTR from a library of $42,500 chemical compounds demonstrates that the advantages of complex iPSC-derived culture systems for disease modeling can also be utilized for drug screening in a true HT format.

The main concern of gene therapy is to target the gene of interest to intended cell tissues for optimizing treatment efficiency. Genetically engineered bacteria have been developed as shuttle vectors for localized delivery of therapeutics. Their success depends upon their tropism to target cells and the efficiency of the engaged delivery system. Bodies of evidence clearly indicate the great potential of recombinant bacteria in gene therapy, although most of the studies were just looking for proof-of-concept rather than a ready-to-use final product. This part will provide an overview of our current understanding of bacteria-based delivery of therapeutic genes and heterologous antigens for prophylactic strategies.

Statewide monitoring of pink bollworm susceptibility to Bt toxin was conducted in Arizona in 1997 and 1998. In bioassays in which Bt toxin was incorporated into insect diet, a concentration of 10 )g/ml Cry1Ac caused >80% mortality of all field populations. LC50s of Arizona populations ranged from 0.35 to 1.7 )g Cry1Ac/ml of insect diet. A laboratory strain of pink bollworm had an LC50 of 0.53 )g/ml. A selection experiment was conducted in which survivors of bioassays of 3.2 and 10 )g/ml of Cry1Ac from all Arizona populations tested in 1997 were pooled and reared for one generation on diet containing 10 )g Cry1Ac/ml. Selection produced a strain of pink bollworm that was 100to 460-fold less susceptible to Cry1Ac, than were the field populations from which it was derived. Preliminary results from greenhouse evaluations concerning survival of this resistant strain on Bt cotton showed that larvae were able to complete development in bolls of Bt cotton, pupate, and successfully reprodu...

Grafting has been used in agriculture for over 2000 years. Disease resistance and environmental tolerance are highly beneficial traits that can be provided through use of grafting, although the mechanisms, in particular for resistance, have frequently been unknown. As information emerges that describes plant disease resistance mechanisms, the proteins, and nucleic acids that play a critical role in disease management can be expressed in genetically engineered (GE) plant lines. Utilizing transgrafting, the combination of a GE rootstock with a wild-type (WT) scion, or the reverse, has the potential to provide pest and pathogen resistance, impart biotic and abiotic stress tolerance, or increase plant vigor and productivity. Of central importance to these potential benefits is the question of to what extent nucleic acids and proteins are transmitted across a graft junction and whether the movement of these molecules will affect the efficacy of the transgrafting approach. Using a variety...

Purpose: Pakistan is one of the few countries where Rabies is endemic and a great threat to humans as well as live stocks. A large number of individuals died of rabies exposure due to either the limited access to rabies vaccines or the side-effects of sheep brain -originated Semple vaccine. Cell culture-derived rabies vaccines are mostly unaffordable to the needed population under rabies threat. Development of a safer and more affordable vaccine is necessary in Pakistan. Here, we developed two novel recombinant rabies virus vaccines using a local Pakistan rabies virus glycoprotein gene, and tested the efficacy of vaccines in mice. The glycoprotein gene (RVG) of vector ERAg 3 p and ERAg 3 m was substituted, respectively, with a modified Pakistani RVG. The resulting recombinant vectors were applied for reverse genetics to recover two vaccine viruses, PK-SG and PK-DG. The efficacy of PK-SG and PK-DG were tested in mice by intramuscular injection and oral delivery. Results: All mice survived the challenge after intramuscular vaccination using PK-SG, or PK-DG. In the oral vaccination groups, 80% mice with PK-SG and 90% mice with PK-DG survived the challenge. Meanwhile, 80% of the unvaccinated control mice succumbed after challenge. The mean rabies virus neutralizing antibody titers was ≥ 0.5 IU/ml in all vaccinated groups. Our results demonstrated the efficacy of PK-SG and PK-DG in rabies vaccination in mice. The two recombinant virus strains may be good vaccine candidates for the target animals and humans in Pakistan. Detailed investigations are necessary in the future.

Rapid advancement in fluorescence and luminescence imaging technology is encouraging cell biologists to develop high-throughput assays for intracellular detection of bioactive small molecules, protein conformational changes, protein localization and dynamics, and measurement of protein—protein interactions in real time at the level of single living cells with high spatial and temporal resolution. In this report, we summarize the development of genetically encoded fluorescent and bioluminescent probes to study various molecular events in live cells and animals for potential drug candidates against different diseases.

Biodistributions of 125 Iodine-labeled fusion proteins in tumors and normal organs of athymic mice bearing Ramos xenografts pretargeted with 125 I-1F5-S45A-SAv, 125 I-1F5-Y43A-SAv, or 125 I-1F5-WT-SAv FP. Mice were fed either normal or biotin-deficient diets for 5-6 days before injection of 2.8 nmol of FPs, as indicated. Twenty-four hours later 5.8 nmol of either monovalent NAGB CA or divalent bis-biotin CA was injected. After another 4 hours, mice were injected with 1.2 nmol of 111 In-labeled DOTA-biotin or 111 Inlabeled bis-biotin . Results are shown for mice sacrificed either 24 hr (A) or 48 hr (B) after administration of the radiolabeled biotin.

The Ecological Society of America has evaluated the ecological effects of current and potential uses of field-released genetically engineered organisms (GEOs), as described in this Position Paper. Some GEOs could play a positive role in sustainable agriculture, forestry, aquaculture, bioremediation, and environmental management, both in developed and developing countries. However, deliberate or inadvertent releases of GEOs into the environment could have negative ecological effects under certain circumstances. Possible risks of GEOs could include: (1) creating new or more vigorous pests and pathogens; (2) exacerbating the effects of existing pests through hybridization with related transgenic organisms; (3) harm to nontarget species, such as soil organisms, non-pest insects, birds, and other animals; (4) disruption of biotic communities, including agroecosystems; and (5) irreparable loss or changes in species diversity or genetic diversity within species. Many potential applications of genetic engineering extend beyond traditional breeding, encompassing viruses, bacteria, algae, fungi, grasses, trees, insects, fish, and shellfish. GEOs that present novel traits will need special scrutiny with regard to their environmental effects. The Ecological Society of America supports the following recommendations. (1) GEOs should be designed to reduce environmental risks. (2) More extensive studies of the environmental benefits and risks associated with GEOs are needed. (3) These effects should be evaluated relative to appropriate baseline scenarios. (4) Environmental release of GEOs should be prevented if scientific knowledge about possible risks is clearly inadequate. (5) In some cases, post-release monitoring will be needed to identify, manage, and mitigate environmental risks. ( ) Science-based regulation should subject all transgenic organisms to a similar risk assessment framework and should incorporate a cautious approach, recognizing that many environmental effects are GEO-and site-specific. (7) Ecologists, agricultural scientists, molecular biologists, and others need broader training and wider collaboration to address these recommendations. In summary, GEOs should be evaluated and used within the context of a scientifically based regulatory policy that encourages innovation without compromising sound environmental management. The Ecological Society of America is committed to providing scientific expertise for evaluating and predicting the ecological effects of field-released transgenic organisms.

The evolution of resistance in target pests to transgenic insecticidal crops is a significant environmental risk. Resistance is the phenotype of an individual that gives the individual the ability to survive on a transgenic insecticidal plant from egg to adult and produce viable offspring. The goal of insect resistance management (IRM) is to delay or prevent the occurrence of control failures from resistance by delaying or preventing the evolution of resistance. A practicable IRM strategy is necessary to attain this goal, which means that the costs associated with implementing IRM should also be considered. In addition, because of the uncertainty in IRM strategies, it is essential to allow the IRM strategy to be changed as new information becomes available. It is widely agreed that resistance evolution can be successfully managed. The simplest approach is to reduce selection pressure by maintaining refuge habitats. The high-dose/refuge strategy is by far the most widely considered and used. This strategy requires that the transgenic insecticidal crop produces a sufficiently high toxin concentration that the resistance allele is rendered recessive, and that a host plant other than the transgenic insecticidal crop is growing nearby as a refuge for the target pest or pests. The strategy works by reducing the selection pressure favouring the resistance alleles. This is done by having a larger refuge and a higher dose. The larger the refuge, the smaller the proportion of the population exposed to selection. The higher the dose, the smaller the fitness advantage of the resistant/susceptible heterozygote over the susceptible homozygote in the transgenic field. A third and quantitatively smaller effect is caused by the mingling and mating between individuals from transgenic and refuge fields, which reduces the rate of formation of resistant homozygote offspring. IRM strategies begin with resistance risk assessment to identify the pest species most at risk. Resistance monitoring is essential to track the progress of resistance evolution and to determine the success of the IRM strategy. Phenotypic monitoring methods are best suited for low-dose events and genic methods are best suited for high-dose events. Resistance risks are real, but they can be managed.

The identi®cation of biological ice nucleating agents and their importance in frost induction and prevention is discussed. The discussion also includes information about the researchers who did the work, their original investigations, and struggles with government agencies to introduce their products. The original research was initiated independently by a group of atmospheric scientists in Wyoming and a group of plant pathologists in Wisconsin. They both discovered that ice does not form randomly but is initiated on a nucleating site which is associated with particular bacterial species, especially Pseudomonas syringae. From this original discovery has come commercial products that are used to prevent frost (Frostban TM [the generic name for bacteria that lack the genes coding for the ability to form ice crystals on the leaves of crop plants (Oei, H.L., 1999. Genes and Politics: The Recombinant DNA Debate. Chatelaine Press, Burke, VA)] and Blightban 1 ), manufacture snow (Snomax 1 ), reduce the incidence of ®re blight (Blightban 1 ), and as an aid for food concentration and texturing. The moral and ethical questions encountered by the scientists Scientia Horticulturae 84 (2000) 179±189

Sudden cardiac death is responsible for several hundred thousand deaths each year in the United States. Multiple lines of evidence suggest that perturbation of gap junction expression and function in the heart, or what has come to be known as cardiac gap junction remodeling, plays a key mechanistic role in the pathophysiology of clinically significant cardiac arrhythmias. Here we review recent studies from our laboratory using genetically engineered murine models to explore mechanisms implicated in pathologic gap junction remodeling and their proarrhythmic consequences, with a particular focus on aberrant posttranslational phosphorylation of connexin43.

Sudden cardiac death is responsible for several hundred thousand deaths each year in the United States. Multiple lines of evidence suggest that perturbation of gap junction expression and function in the heart, or what has come to be known as cardiac gap junction remodeling, plays a key mechanistic role in the pathophysiology of clinically significant cardiac arrhythmias. Here we review recent studies from our laboratory using genetically engineered murine models to explore mechanisms implicated in pathologic gap junction remodeling and their proarrhythmic consequences, with a particular focus on aberrant posttranslational phosphorylation of connexin43.

A scientific approach to the assessment of foods derived from genetically engineered (GE) crops is critical to maintaining objectivity and public confidence in regulatory decisions. Principles developed at the international level support regulators and enable robust and transparent safety assessments. A comparison of key constituents in the GE crop with a suitable comparator is an important element of an assessment. In Europe, endogenous allergens would be included in the comparative analysis, however this approach has been hindered by technical limitations on the ability to accurately measure identified allergenic proteins. Over recent years, improved proteomic methods have enabled researchers to focus on major allergenic proteins in conventional food crops, as information on natural variability is largely lacking. Emerging data for soybean indicate that variability in levels of major allergens already in the food supply is broad. This raises questions about the biological interpre...

Precise control over the threshold voltage of pentacene-based organic thin film transistors was achieved by inserting a genetically engineered quartz-binding polypeptide at the semiconductor-dielectric interface. A 30 V range was accessed with the same peptide by adjusting the pH of the solution for peptide assembly while leaving other device properties unaffected. Mobility of 0.1-0.2 cm 2 V -1 s -1 and on/off current ratio of Ͼ10 6 could be achieved for all devices regardless of the presence of the neutral peptide or the peptide assembled in acidic or basic conditions. This shift in threshold voltages is explained by the generation of charged species and dipoles due to variation in assembling conditions. Controlling device characteristics such as threshold voltage is essential for integration of transistors into electronic circuits.

We present examples of ordered assemblies of organic and biological molecules on gold(111) surfaces. The first example shows how control over mono-or multilayer assemblies of 1,4phenylenedimethanthiol can be achieved and monitored. The second example shows how monolayers on gold can be prepared using amine groups to anchor aromatic molecules to the surface. A third example shows how ordered assemblies of geneticallyengineered inorganic-binding polypeptides can be formed on gold surfaces using a 3-repeat, 14 amino acid gold-binding protein (GBP1).

Precise control over the threshold voltage of pentacene-based organic thin film transistors was achieved by inserting a genetically engineered quartz-binding polypeptide at the semiconductor-dielectric interface. A 30 V range was accessed with the same peptide by adjusting the pH of the solution for peptide assembly while leaving other device properties unaffected. Mobility of 0.1–0.2 cm2 V−1 s−1 and on/off current ratio of >106 could be achieved for all devices regardless of the presence of the neutral peptide or the peptide assembled in acidic or basic conditions. This shift in threshold voltages is explained by the generation of charged species and dipoles due to variation in assembling conditions. Controlling device characteristics such as threshold voltage is essential for integration of transistors into electronic circuits.