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Sample records for genetically modified maize

  1. Unconventional P-35S sequence identified in genetically modified maize.

    PubMed

    Al-Hmoud, Nisreen; Al-Husseini, Nawar; Ibrahim-Alobaide, Mohammed A; Kübler, Eric; Farfoura, Mahmoud; Alobydi, Hytham; Al-Rousan, Hiyam

    2014-01-01

    The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan's markets during the period 2009 and 2012. PMID:24495911

  2. Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

    PubMed

    Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

    2002-01-01

    Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system. PMID:12083257

  3. Individual detection of genetically modified maize varieties in non-identity-preserved maize samples.

    PubMed

    Akiyama, Hiroshi; Sakata, Kozue; Kondo, Kazunari; Tanaka, Asako; Liu, Ming S; Oguchi, Taichi; Furui, Satoshi; Kitta, Kazumi; Hino, Akihiro; Teshima, Reiko

    2008-03-26

    In many countries, the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved GM varieties. The GMO content in a maize sample containing the combined-trait (stacked) GM maize as determined by the currently available methodology is likely to be overestimated. However, there has been little information in the literature on the mixing level and varieties of stacked GM maize in real sample grains. For the first time, the GMO content of non-identity-preserved (non-IP) maize samples imported from the United States has been successfully determined by using a previously developed individual kernel detection system coupled to a multiplex qualitative PCR method followed by multichannel capillary gel electrophoresis system analysis. To clarify the GMO content in the maize samples imported from the United States, determine how many stacked GM traits are contained therein, and which GM trait varieties frequently appeared in 2005, the GMO content (percent) on a kernel basis and the varieties of the GM kernels in the non-IP maize samples imported from the United States were investigated using the individual kernel analysis system. The average (+/-standard deviation) of the GMO contents on a kernel basis in five non-IP sample lots was determined to be 51.0+/-21.6%, the percentage of a single GM trait grains was 39%, and the percentage of the stacked GM trait grains was 12%. The MON810 grains and NK603 grains were the most frequent varieties in the single GM traits. The most frequent stacked GM traits were the MON810xNK603 grains. In addition, the present study would provide the answer and impact for the quantification of GM maize content in the GM maize kernels on labeling regulation. PMID:18298063

  4. Effect of Feeding Cows Genetically Modified Maize on the Bacterial Community in the Bovine Rumen▿

    PubMed Central

    Wiedemann, S.; Gürtler, P.; Albrecht, C.

    2007-01-01

    Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics of six ruminal bacterial strains (investigated by real-time PCR) compared to the conventional maize silage. PMID:17933942

  5. A multiplex PCR method of detecting recombinant DNAs from five lines of genetically modified maize.

    PubMed

    Matsuoka, T; Kuribara, H; Akiyama, H; Miura, H; Goda, Y; Kusakabe, Y; Isshiki, K; Toyoda, M; Hino, A

    2001-02-01

    Seven lines of genetically modified (GM) maize have been authorized in Japan as foods and feeds imported from the USA. We improved a multiplex PCR method described in the previous report in order to distinguish the five lines of GM maize. Genomic DNA was extracted from GM maize with a silica spin column kit, which could reduce experimental time and improve safety in the laboratory and potentially in the environment. We sequenced recombinant DNA (r-DNA) introduced into GM maize, and re-designed new primer pairs to increase the specificity of PCR to distinguish five lines of GM maize by multiplex PCR. A primer pair for the maize intrinsic zein gene (Ze1) was also designed to confirm the presence of amplifiable maize DNA. The lengths of PCR products using these six primer pairs were different. The Ze1 and the r-DNAs from the five lines of GM maize were qualitatively detected in one tube. The specific PCR bands were distinguishable from each other on the basis of the expected length. The r-DNA could be detected from maize samples containing 0.5% of each of the five lines of GM maize. The sensitivity would be acceptable to secure the verification of non-GMO materials and to monitor the reliability of the labeling system. PMID:11383153

  6. Automated DNA extraction from genetically modified maize using aminosilane-modified bacterial magnetic particles.

    PubMed

    Ota, Hiroyuki; Lim, Tae-Kyu; Tanaka, Tsuyoshi; Yoshino, Tomoko; Harada, Manabu; Matsunaga, Tadashi

    2006-09-18

    A novel, automated system, PNE-1080, equipped with eight automated pestle units and a spectrophotometer was developed for genomic DNA extraction from maize using aminosilane-modified bacterial magnetic particles (BMPs). The use of aminosilane-modified BMPs allowed highly accurate DNA recovery. The (A(260)-A(320)):(A(280)-A(320)) ratio of the extracted DNA was 1.9+/-0.1. The DNA quality was sufficiently pure for PCR analysis. The PNE-1080 offered rapid assay completion (30 min) with high accuracy. Furthermore, the results of real-time PCR confirmed that our proposed method permitted the accurate determination of genetically modified DNA composition and correlated well with results obtained by conventional cetyltrimethylammonium bromide (CTAB)-based methods. PMID:16621089

  7. Between myth and reality: genetically modified maize, an example of a sizeable scientific controversy.

    PubMed

    Wisniewski, Jean-Pierre; Frangne, Nathalie; Massonneau, Agnès; Dumas, Christian

    2002-11-01

    Maize is a major crop plant with essential agronomical interests and a model plant for genetic studies. With the development of plant genetic engineering technology, many transgenic strains of this monocotyledonous plant have been produced over the past decade. In particular, field-cultivated insect-resistant Bt-maize hybrids are at the centre of an intense debate between scientists and organizations recalcitrant to genetically modified organisms (GMOs). This debate, which addresses both safety and ethical aspects, has raised questions about the impact of genetically modified (GM) crops on the biodiversity of traditional landraces and on the environment. Here, we review some of the key points of maize genetic history as well as the methods used to stably transform this cereal. We describe the genetically engineered Bt-maizes available for field cultivation and we investigate the controversial reports on their impacts on non-target insects such as the monarch butterfly and on the flow of transgenes into Mexican maize landraces. PMID:12595137

  8. Evaluation of modified PCR quantitation of genetically modified maize and soybean using reference molecules: interlaboratory study.

    PubMed

    Kodama, Takashi; Kuribara, Hideo; Minegishi, Yasutaka; Futo, Satoshi; Watai, Masatoshi; Sawada, Chihiro; Watanabe, Takahiro; Akiyama, Hiroshi; Maitani, Tamio; Teshima, Reiko; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

    2009-01-01

    Real-time polymerase chain reaction (PCR)-based quantitative methods were previously developed and validated for genetically modified (GM) maize or soy. In this study, the quantification step of the validated methods was modified, and an interlaboratory study was conducted. The modification included the introduction of the PCR system SSIIb 3 instead of SSIIb 1 for the detection of the taxon-specific sequence of maize, as well as the adoption of colE1 as a carrier included in a reference plasmid solution as a replacement for salmon testis. The interlaboratory study was conducted with the ABI PRISM 7700 and consisted of 2 separate stages: (1) the measurement of conversion factor (Cf) value, which is the ratio of recombinant DNA (r-DNA) sequence to taxon-specific sequence in each genuine GM seed, and (2) the quantification of blind samples. Additionally, Cf values of other instruments, such as the ABI PRISM 7900 and the ABI PRISM 7000, were measured in a multilaboratory trial. After outlier laboratories were eliminated, the repeatability and reproducibility for 5.0% samples were <15.8 and 20.6%, respectively. The quantitation limits of these methods were 0.5% for Bt11, T25, and MON810, and 0.1% for GA21, Event176, and RR soy. The quantitation limits, trueness, and precision of the current modified methods were equivalent to those of the previous methods. Therefore, it was concluded that the modified methods would be a suitable replacement for the validated methods. PMID:19382580

  9. Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

    PubMed

    Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

    2016-04-01

    This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea maysL.) on growth and germination of succeeding crop wheat (Triticum aestivumL.) and associated weed (Avena fatuaL.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatuaL.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. PMID:24215059

  10. Novel reference molecules for quantitation of genetically modified maize and soybean.

    PubMed

    Kuribara, Hideo; Shindo, Yoichiro; Matsuoka, Takeshi; Takubo, Ken; Futo, Satoshi; Aoki, Nobutaro; Hirao, Takashi; Akiyama, Hiroshi; Goda, Yukihiro; Toyoda, Masatake; Hino, Akihiro

    2002-01-01

    New quantitation methods based on a real-time polymerase chain reaction (PCR) technique were developed for 5 lines of genetically modified (GM) maize, including MON810, Event176, Bt11, T25, and GA21, and a GM soy, Roundup Ready. Oligonucleotide DNA, including specific primers and fluorescent dye-labeled probes, were designed for PCRs. Two plasmids were constructed as reference molecules (RMs) for the detection of GM maize and GM soy. The molecules contain the DNA sequences of a specific region found in each GM line, universal sequences used in various GM lines, such as cauliflower mosaic virus 35S promoter and nopaline synthase terminator, and the endogenous DNA sequences of maize or soy. By using these plasmids, no GM maize and GM soy were required as reference materials for the qualitative and quantitative PCR technique. Test samples containing 0, 0.10, 0.50, 1.0, 5.0, and 10% GM maize or GM soy were quantitated. At the 5.0% level, the bias (mean-true value) ranged from 2.8 to 19.4% and the relative standard deviation was <5.2%. These results show that our method involving the use of these plasmids as RMs is reliable and practical for quantitation of GM maize and GM soy. PMID:12374407

  11. Detection of genetically modified maize in processed foods sold commercially in iran by qualitative PCR.

    PubMed

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer's right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  12. Detection of Genetically Modified Maize in Processed Foods Sold Commercially in Iran by Qualitative PCR

    PubMed Central

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer’s right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  13. Loop-mediated isothermal amplification (LAMP) method for detection of genetically modified maize T25

    PubMed Central

    Xu, Junyi; Zheng, Qiuyue; Yu, Ling; Liu, Ran; Zhao, Xin; Wang, Gang; Wang, Qinghua; Cao, Jijuan

    2013-01-01

    The loop-mediated isothermal amplification (LAMP) assay indicates a potential and valuable means for genetically modified organism (GMO) detection especially for its rapidity, simplicity, and low cost. We developed and evaluated the specificity and sensitivity of the LAMP method for rapid detection of the genetically modified (GM) maize T25. A set of six specific primers was successfully designed to recognize six distinct sequences on the target gene, including a pair of inner primers, a pair of outer primers, and a pair of loop primers. The optimum reaction temperature and time were verified to be 65°C and 45 min, respectively. The detection limit of this LAMP assay was 5 g kg−1 GMO component. Comparative experiments showed that the LAMP assay was a simple, rapid, accurate, and specific method for detecting the GM maize T25. PMID:24804053

  14. DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products.

    PubMed

    Turkec, Aydin; Kazan, Hande; Karacanli, Burçin; Lucas, Stuart J

    2015-08-01

    In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products. PMID:26243938

  15. Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

    PubMed

    Devos, Yann; Cougnon, Mathias; Vergucht, Sofie; Bulcke, Robert; Haesaert, Geert; Steurbaut, Walter; Reheul, Dirk

    2008-12-01

    With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize. Impacts on human health and the environment were calculated through the pesticide occupational and environmental risk (POCER) indicator. Results showed that the environmental impact of herbicide regimes solely relying on the active ingredients glyphosate (GLY) or glufosinate-ammonium (GLU) is lower than that of herbicide regimes applied in non-GMHR maize. Due to the lower potential of GLY and GLU to contaminate ground water and their lower acute toxicity to aquatic organisms, the POCER exceedence factor values for the environment were reduced approximately by a sixth when GLY or GLU is used alone. However, the environmental impact of novel herbicide regimes tested may be underestimated due to the assumption that active ingredients used with GMHR maize would be used alone. Data retrieved from literature suggest that weed control efficacy is increased and resistance development delayed when GLY or GLU is used together with other herbicides in the GMHR system. Due to the partial instead of complete replacement of currently used herbicide regimes, the beneficial environmental impact of novel herbicide regimes might sometimes be reduced or counterbalanced. Despite the high weed control efficacy provided by the biotechnology-based weed management strategy, neither indirect harmful effects on farmland biodiversity through losses in food resources and shelter, nor shifts in weed communities have been demonstrated in GMHR maize yet. However, with the increasing adoption rate of GMHR maize and their associated novel herbicide regimes, this situation is expected to change in the short-term. PMID:18404410

  16. First application of a microsphere-based immunoassay to the detection of genetically modified organisms (GMOs): quantification of Cry1Ab protein in genetically modified maize.

    PubMed

    Fantozzi, Anna; Ermolli, Monica; Marini, Massimiliano; Scotti, Domenico; Balla, Branko; Querci, Maddalena; Langrell, Stephen R H; Van den Eede, Guy

    2007-02-21

    An innovative covalent microsphere immunoassay, based on the usage of fluorescent beads coupled to a specific antibody, was developed for the quantification of the endotoxin Cry1Ab present in MON810 and Bt11 genetically modified (GM) maize lines. In particular, a specific protocol was developed to assess the presence of Cry1Ab in a very broad range of GM maize concentrations, from 0.1 to 100% [weight of genetically modified organism (GMO)/weight]. Test linearity was achieved in the range of values from 0.1 to 3%, whereas fluorescence signal increased following a nonlinear model, reaching a plateau at 25%. The limits of detection and quantification were equal to 0.018 and 0.054%, respectively. The present study describes the first application of quantitative high-throughput immunoassays in GMO analysis. PMID:17300145

  17. Effect on soil chemistry of genetically modified (GM) vs. non-GM maize.

    PubMed

    Liu, Na; Zhu, Ping; Peng, Chang; Kang, Lingsheng; Gao, Hongjun; Clarke, Nicholas J; Clarke, Jihong Liu

    2010-01-01

    The effects of genetically modified (GM) maize (Zea mays L.) expressing the Bacillus thuringiensis Berliner Cry1Fa2 protein (Bt) and phosphinothricin or glyphosate herbicide tolerance on soil chemistry (organic matter, N, P, K and pH), compared with non-GM controls, were assessed in field and pot experiments. In the field experiment, NH(4)(+) was significantly higher in soil under the crop modified for herbicide tolerance compared to the control (mean values of 11 and 9.6 mg N/kg respectively) while P was significantly higher in soil under the control compared to under the GM crop (mean values of 6.9 and 6.4 dg P/kg, respectively). No significant differences were found as a result of growing Bt/herbicide tolerant maize. In the pot experiment, using soils from three sites (Gongzhuling, Dehui and Huadian), significant effects of using Bt maize instead of conventional maize were found for all three soils. In the Gongzhuling soil, P was significantly higher in soil under the control compared to under the GM crop (mean values of 4.8 and 4.0 dg P/kg, respectively). For the Dehui soil, the pH was significantly higher in soil under the control compared to under the GM crop (mean values for {H(+)} of 1.1 and 2.4 μM for the control and the GM crop respectively). In the Huadian soil, organic matter and total N were both higher in soil under the GM crop than under the control. For organic matter, the mean values were 3.0 and 2.9% for the GM crop and the control, respectively, while for total nitrogen the mean values were 2.02 and 1.96% for the GM crop and the control respectively. Our results indicate that growing GM crops instead of conventional crops may alter soil chemistry, but not greatly, and that effects will vary with both the specific genetic modification and the soil. PMID:21844670

  18. Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

    PubMed Central

    Mathur, Chandni; Kathuria, Pooran C.; Dahiya, Pushpa; Singh, Anand B.

    2015-01-01

    Background Genetically modified, (GM) crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release. Objective To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize. Methods An integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE) and Immunoblot using food sensitized patients sera (n = 39) to non GM and GM maize antigens was performed. Results In silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05) variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF) revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF. Conclusion Cry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize. PMID:25706412

  19. A look at product development with genetically modified crops: examples from maize.

    PubMed

    Mumm, Rita H

    2013-09-01

    Plant breeding for crop genetic improvement involves the cycle of creating genetic diversity and exploiting that diversity to derive an improved cultivar with outstanding performance for specific traits of interest. Genetic modification through transformation essentially expands the genepool to facilitate access to genes otherwise not available through crossing. Transgenic events are defined by the DNA sequence that has been incorporated into the target genome and the specific point(s) of insertion. In the development of a new transgenic trait, typically many events are generated and evaluated with the aim of identifying one exhibiting consistent trait expression at or above specified thresholds, stable inheritance, and the absence of any negative effects. With transgenic traits for maize, once commercial candidates have been identified, these events are introgressed into elite lines, often through the use of molecular markers that can accelerate the breeding process and aid in producing a quality conversion. Converted elite lines are yield-tested to ensure performance equivalency with their unconverted counterparts. Finally, before commercial sale of seed, quality control monitoring is conducted to ensure event identity and purity and the absence of any unintended events. This monitoring complements other quality control measures to confirm seed viability and line/hybrid purity and uniformity in seed treatments, all in an effort to ensure customer satisfaction and to comply with governmental regulations. Thus, genetically modified (GM) cultivars are subject to significant testing and auditing prior to seed sale and distribution to farmers, more testing and auditing than with non-GM cultivars. PMID:23668783

  20. Effects of insecticidal crystal proteins (Cry proteins) produced by genetically modified maize (Bt maize) on the nematode Caenorhabditis elegans.

    PubMed

    Höss, Sebastian; Menzel, Ralph; Gessler, Frank; Nguyen, Hang T; Jehle, Johannes A; Traunspurger, Walter

    2013-07-01

    The genetically modified maize MON89034 × MON88017 expresses different crystal (Cry) proteins with pesticidal activity against the European corn borer (Cry1.105; Cry2Ab2) and the Western corn root worm (Cry3Bb1). Non-target organisms, such as soil nematodes, might be exposed to the Cry proteins that enter the soil in course of crop growing. Therefore, the risk of those proteins for nematodes was assessed by testing their toxic effects on Caenorhabditis elegans. All three insecticidal Cry proteins showed dose-dependent inhibitory effects on C. elegans reproduction (EC50: 0.12-0.38 μmol L(-1)), however, at concentrations that were far above the expected soil concentrations. Moreover, a reduced toxicity was observed when Cry proteins were added jointly. A C. elegans mutant strain deficient for receptors for the nematicidal Cry5B was also resistant against Cry1.105 and Cry2Ab2, suggesting that these Cry proteins bound to the same or similar receptors as nematicidal Cry proteins and thereby affect the reproduction of C. elegans. PMID:23570782

  1. Detection of airborne genetically modified maize pollen by real-time PCR.

    PubMed

    Folloni, Silvia; Kagkli, Dafni-Maria; Rajcevic, Bojan; Guimarães, Nilson C C; Van Droogenbroeck, Bart; Valicente, Fernando H; Van den Eede, Guy; Van den Bulcke, Marc

    2012-09-01

    The cultivation of genetically modified (GM) crops has raised numerous concerns in the European Union and other parts of the world about their environmental and economic impact. Especially outcrossing of genetically modified organisms (GMO) was from the beginning a critical issue as airborne pollen has been considered an important way of GMO dispersal. Here, we investigate the use of airborne pollen sampling combined with microscopic analysis and molecular PCR analysis as an approach to monitor GM maize cultivations in a specific area. Field trial experiments in the European Union and South America demonstrated the applicability of the approach under different climate conditions, in rural and semi-urban environment, even at very low levels of airborne pollen. The study documents in detail the sampling of GM pollen, sample DNA extraction and real-time PCR analysis. Our results suggest that this 'GM pollen monitoring by bioaerosol sampling and PCR screening' approach might represent an useful aid in the surveillance of GM-free areas, centres of origin and natural reserves. PMID:22805239

  2. Comparative proteomic analysis of genetically modified maize grown under different agroecosystems conditions in Brazil

    PubMed Central

    2013-01-01

    Background Profiling technologies allow the simultaneous measurement and comparison of thousands of cell components without prior knowledge of their identity. In the present study, we used two-dimensional gel electrophoresis combined with mass spectrometry to evaluate protein expression of Brazilian genetically modified maize hybrid grown under different agroecosystems conditions. To this effect, leaf samples were subjected to comparative analysis using the near-isogenic non-GM hybrid as the comparator. Results In the first stage of the analysis, the main sources of variation in the dataset were identified by using Principal Components Analysis which correlated most of the variation to the different agroecosystems conditions. Comparative analysis within each field revealed a total of thirty two differentially expressed proteins between GM and non-GM samples that were identified and their molecular functions were mainly assigned to carbohydrate and energy metabolism, genetic information processing and stress response. Conclusions To the best of our knowledge this study represents the first evidence of protein identities with differentially expressed isoforms in Brazilian MON810 genetic background hybrid grown under field conditions. As global databases on outputs from “omics” analysis become available, these could provide a highly desirable benchmark for safety assessments. PMID:24304660

  3. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize.

    PubMed

    Séralini, Gilles-Eric; Clair, Emilie; Mesnage, Robin; Gress, Steeve; Defarge, Nicolas; Malatesta, Manuela; Hennequin, Didier; de Vendômois, Joël Spiroux

    2012-11-01

    The health effects of a Roundup-tolerant genetically modified maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone (from 0.1 ppb in water), were studied 2 years in rats. In females, all treated groups died 2-3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs. All results were hormone and sex dependent, and the pathological profiles were comparable. Females developed large mammary tumors almost always more often than and before controls, the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5-5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3-2.3 greater. Males presented 4 times more large palpable tumors than controls which occurred up to 600 days earlier. Biochemistry data confirmed very significant kidney chronic deficiencies; for all treatments and both sexes, 76% of the altered parameters were kidney related. These results can be explained by the non linear endocrine-disrupting effects of Roundup, but also by the overexpression of the transgene in the GMO and its metabolic consequences. PMID:22999595

  4. Establishment of Quantitative Analysis Method for Genetically Modified Maize Using a Reference Plasmid and Novel Primers

    PubMed Central

    Moon, Gi-Seong; Shin, Weon-Sun

    2012-01-01

    For the quantitative analysis of genetically modified (GM) maize in processed foods, primer sets and probes based on the 35S promoter (p35S), nopaline synthase terminator (tNOS), p35S-hsp70 intron, and zSSIIb gene encoding starch synthase II for intrinsic control were designed. Polymerase chain reaction (PCR) products (80~101 bp) were specifically amplified and the primer sets targeting the smaller regions (80 or 81 bp) were more sensitive than those targeting the larger regions (94 or 101 bp). Particularly, the primer set 35F1-R1 for p35S targeting 81 bp of sequence was even more sensitive than that targeting 101 bp of sequence by a 3-log scale. The target DNA fragments were also specifically amplified from all GM labeled food samples except for one item we tested when 35F1-R1 primer set was applied. A reference plasmid pGMmaize (3 kb) including the smaller PCR products for p35S, tNOS, p35S-hsp70 intron, and the zSSIIb gene was constructed for real-time PCR (RT-PCR). The linearity of standard curves was confirmed by using diluents ranging from 2×101~105 copies of pGMmaize and the R2 values ranged from 0.999~1.000. In the RT-PCR, the detection limit using the novel primer/probe sets was 5 pg of genomic DNA from MON810 line indicating that the primer sets targeting the smaller regions (80 or 81 bp) could be used for highly sensitive detection of foreign DNA fragments from GM maize in processed foods. PMID:24471096

  5. Genotypic and Environmental Impact on Natural Variation of Nutrient Composition in 50 Non Genetically Modified Commercial Maize Hybrids in North America.

    PubMed

    Cong, Bin; Maxwell, Carl; Luck, Stanley; Vespestad, Deanne; Richard, Keith; Mickelson, James; Zhong, Cathy

    2015-06-10

    This study was designed to assess natural variation in composition and metabolites in 50 genetically diverse non genetically modified maize hybrids grown at six locations in North America. Results showed that levels of compositional components in maize forage were affected by environment more than genotype. Crude protein, all amino acids except lysine, manganese, and β-carotene in maize grain were affected by environment more than genotype; however, most proximates and fibers, all fatty acids, lysine, most minerals, vitamins, and secondary metabolites in maize grain were affected by genotype more than environment. A strong interaction between genotype and environment was seen for some analytes. The results could be used as reference values for future nutrient composition studies of genetically modified crops and to expand conventional compositional data sets. These results may be further used as a genetic basis for improvement of the nutritional value of maize grain by molecular breeding and biotechnology approaches. PMID:25971869

  6. Evaluation of stress- and immune-response biomarkers in Atlantic salmon, Salmo salar L., fed different levels of genetically modified maize (Bt maize), compared with its near-isogenic parental line and a commercial suprex maize.

    PubMed

    Sagstad, A; Sanden, M; Haugland, Ø; Hansen, A-C; Olsvik, P A; Hemre, G-I

    2007-04-01

    The present study was designed to evaluate if genetically modified (GM) maize (Bt maize, event MON810) compared with the near-isogenic non-modified (nGM) maize variety, added as a starch source at low or high inclusions, affected fish health of post-smolt Atlantic salmon, Salmo salar L. To evaluate the health impact, selected stress- and immune-response biomarkers were quantified at the gene transcript (mRNA) level, and some also at the protein level. The diets with low or high inclusions of GM maize, and its near-isogenic nGM parental line, were compared to a control diet containing GM-free suprex maize (reference diet) as the only starch source. Total superoxide dismutase (SOD) activity in liver and distal intestine was significantly higher in fish fed GM maize compared with fish fed nGM maize and with the reference diet group. Fish fed GM maize showed significantly lower catalase (CAT) activity in liver compared with fish fed nGM maize and to the reference diet group. In contrast, CAT activity in distal intestine was significantly higher for fish fed GM maize compared with fish fed reference diet. Protein level of heat shock protein 70 (HSP70) in liver was significantly higher in fish fed GM maize compared with fish fed the reference diet. No diet-related differences were found in normalized gene expression of SOD, CAT or HSP70 in liver or distal intestine. Normalized gene expression of interleukin-1 beta in spleen and head-kidney did not vary significantly between diet groups. Interestingly, fish fed high GM maize showed a significantly larger proportion of plasma granulocytes, a significantly larger sum of plasma granulocyte and monocyte proportions, but a significantly smaller proportion of plasma lymphocytes, compared with fish fed high nGM maize. In conclusion, Atlantic salmon fed GM maize showed some small changes in stress protein levels and activities, but none of these changes were comparable to the normalized gene expression levels analysed for these stress proteins. GM maize seemed to induce significant changes in white blood cell populations which are associated with an immune response. PMID:17394522

  7. Decomposition dynamics and structural plant components of genetically modified Bt maize leaves do not differ from leaves of conventional hybrids.

    PubMed

    Zurbrügg, Corinne; Hönemann, Linda; Meissle, Michael; Romeis, Jörg; Nentwig, Wolfgang

    2010-04-01

    The cultivation of genetically modified Bt maize has raised environmental concerns, as large amounts of plant residues remain in the field and may negatively impact the soil ecosystem. In a field experiment, decomposition of leaf residues from three genetically modified (two expressing the Cry1Ab, one the Cry3Bb1 protein) and six non-transgenic hybrids (the three corresponding non-transformed near-isolines and three conventional hybrids) was investigated using litterbags. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e., C:N ratio, lignin, cellulose, hemicellulose) were examined. Furthermore, Cry1Ab and Cry3Bb1 protein concentrations in maize leaf residues were measured from harvest to the next growing season. While leaf residue decomposition in transgenic and non-transgenic plants was similar, differences among conventional cultivars were evident. Similarly, plant components among conventional hybrids differed more than between transgenic and non-transgenic hybrids. Moreover, differences in senescent plant material collected directly from plants were larger than after exposure to soil for 5 months. While the concentration of Cry3Bb1 was higher in senescent maize leaves than that of Cry1Ab, degradation was faster, indicating that Cry3Bb1 has a shorter persistence in plant residues. As decomposition patterns of Bt-transgenic maize were shown to be well within the range of common conventional hybrids, there is no indication of ecologically relevant, adverse effects on the activity of the decomposer community. PMID:19609704

  8. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified (GM) Bt-maize offers an additional means of control against W...

  9. Maize Genetic Resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the resources held at the Maize Genetics Cooperation Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

  10. Representative taxa in field trials for environmental risk assessment of genetically modified maize.

    PubMed

    Albajes, R; Lumbierres, B; Pons, X; Comas, J

    2013-12-01

    When assessing the benefits and risks of transgenic crops, one consideration is their relative effects on non-target arthropod (NTA) abundance and functions within agroecosystems. Several laboratory and field trials have been conducted in Spain since the late 1990s to assess this issue. A consideration in the design of field trials is whether it is necessary to sample most NTAs living in the crop or only representative taxa that perform main ecological functions and have a good capacity to detect small changes in their abundance. Small changes in the field abundance of an effective representative taxon should be detectable using standard experimental protocols. The ability of a species to reveal differences across treatments may be analysed by examining the detectable treatment effects for surveyed non-target organisms. Analysis of data from several NTAs recorded in 14 field trials conducted over 10 years using complete block designs allowed us to select a number of representative taxa capable of detecting changes in the density or activity of arthropod herbivores, predators, parasitoids and decomposers in transgenic and non-transgenic maize varieties. The most suitable NTA as representative taxa (with detectable treatment effects below 50%) included leafhoppers among arthropod herbivores, Orius spp., Araneae, and Carabidae among predators, chalcidids, particularly the family Mymaridae, among parasitoids and Chloropidae as decomposer. Details of sampling techniques for each sampled taxa and their advantages and disadvantages are discussed. It is concluded that abundance of taxa is the most influential factor determining their capacity to detect changes caused by genetically modified varieties. PMID:23987801

  11. Occurrence and field densities of Coleoptera in the maize herb layer: implications for Environmental Risk Assessment of genetically modified Bt-maize.

    PubMed

    Rauschen, Stefan; Schaarschmidt, Frank; Gathmann, Achim

    2010-10-01

    Beetles (Coleoptera) are a diverse and ecologically important group of insects in agricultural systems. The Environmental Risk Assessment (ERA) of genetically modified Bt-crop varieties with insect resistances thus needs to consider and assess the potential negative impacts on non-target organisms belonging to this group. We analysed data gathered during 6 years of field-release experiments on the impact of two genetically modified Bt-maize varieties (Ostrinia-resistant MON810 and Diabrotica-resistant MON88017) on the occurrence and field densities of Coleoptera, especially the two families Coccinellidae and Chrysomelidae. Based on a statistical analysis aimed at establishing whether Bt-maize varieties are equivalent to their near-isogenic counterparts, we discuss the limitations of using field experiments to assess the effects of Bt-maize on these two beetle families. The densities of most of the beetle families recorded in the herb layer were very low in all growing seasons. Coccinellidae and Chrysomelidae were comparatively abundant and diverse, but still low in numbers. Based on their role as biological control agents, Coccinellidae should be a focus in the ERA of Bt-plants, but given the large natural variability in ladybird densities in the field, most questions need to be addressed in low-tier laboratory tests. Chrysomelidae should play a negligible role in the ERA of Bt-plants, since they occur on-crop as secondary pests only. Species occurring off-crop, however, can be addressed in a similar fashion as non-target Lepidoptera in Cry1Ab expressing Bt-maize. PMID:20012775

  12. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment

    PubMed Central

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J.; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes. PMID:24937207

  13. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment.

    PubMed

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes. PMID:24937207

  14. Ultra-fast simultaneous analysis of genetically modified organisms in maize by microchip electrophoresis with LIF detector.

    PubMed

    Kumar, Kailasa Suresh; Kang, Seong Ho

    2007-11-01

    This study examined the potential of microchip electrophoresis (ME) with a LIF detector using a programmed field strength gradient (PFSG) in a conventional glass double-T microchip for the ultra-fast detection and simultaneous analysis of genetically modified (GM) maize. The separation efficiency and sensitivity at various sieving gels (poly(ethylene oxide) (PEO, M(r) 8,000,000) and 2-hydroxyethylcellulose (HEC) (M(r) 250,000)) and fluorescent dye concentrations were investigated. The PCR products of both the GM and non-GM maize were analyzed within 30 s under the PFSG (470.6 V/cm for 20 s, 117.6 V/cm for 12 s, and 470.6 V/cm for 30 s) with a 2.5% HEC sieving matrix in the running buffer, 1 x Tris-borate EDTA (TBE) (pH 8.30) and 0.5 ppm ethidium bromide. The five transgenic maize varieties (Event176, MON810, Bt11, GA21, and T25) examined in this study were also clearly differentiated by ME-PFSG within 30 s in a single run without any loss of resolution. The ME-PFSG technique is a powerful tool for the ultra-fast detection and simultaneous analysis of GMOs in a variety of foods including maize. PMID:17932874

  15. Molecular level lignin patterns of genetically modified Bt-maize MON88017 and three conventional varieties using tetramethylammonium hydroxide (TMAH)-induced thermochemolysis.

    PubMed

    Poerschmann, Juergen; Rauschen, Stefan; Langer, Uwe; Augustin, Juergen; Górecki, Tadeusz

    2008-12-24

    Bt-maize MON88017, its near-isogenic line DKC5143, and the two conventional varieties DK315 and Benicia were subjected to tetramethylammonium hydroxide (TMAH)-induced thermochemolysis to reveal molecular level lignin patterns. MON88017 is genetically modified to express the Cry3Bb1 protein aimed at the Western corn rootworm Diabrotica virgifera virgifera, a serious threat for European maize production. The results indicated that roots of the Bt-maize were characterized by a slightly enhanced total lignin content (by approximately 7%) compared to the near-isogenic line, whereas the molecular-based patterns, expressed by the relative fractions of p-hydroxyphenyl, guaiacyl, and syringyl breakdown products (P-, G-, and S-units, respectively) were virtually identical for both lines. No effects regarding either total lignin or molecular-based lignin patterns could be observed for leaves, indicating that biogenesis of lignin was not pleiotropically affected by the genetic modification. Significant differences for both total lignin and different lignin proxies existed between the conventional maize lines. Molecular level lignin analysis by means of TMAH-induced thermochemolysis is able to distinguish conventional maize varieties. Further work is necessary to evaluate lignin-related pleiotropic effects in genetically modified maize plants. The validation and application of a commonly accepted method for lignin analysis, capable of characterizing lignin at the molecular level, is a prerequisite. PMID:19053395

  16. Sequence-Based Analysis of the Intestinal Microbiota of Sows and Their Offspring Fed Genetically Modified Maize Expressing a Truncated Form of Bacillus thuringiensis Cry1Ab Protein (Bt Maize)

    PubMed Central

    Buzoianu, Stefan G.; Walsh, Maria C.; Rea, Mary C.; Quigley, Lisa; O'Sullivan, Orla; Cotter, Paul D.; Ross, R. Paul; Lawlor, Peadar G.

    2013-01-01

    The aim was to investigate transgenerational effects of feeding genetically modified (GM) maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt maize) to sows and their offspring on maternal and offspring intestinal microbiota. Sows were assigned to either non-GM or GM maize dietary treatments during gestation and lactation. At weaning, offspring were assigned within sow treatment to non-GM or GM maize diets for 115 days, as follows: (i) non-GM maize-fed sow/non-GM maize-fed offspring (non-GM/non-GM), (ii) non-GM maize-fed sow/GM maize-fed offspring (non-GM/GM), (iii) GM maize-fed sow/non-GM maize-fed offspring (GM/non-GM), and (iv) GM maize-fed sow/GM maize-fed offspring (GM/GM). Offspring of GM maize-fed sows had higher counts of fecal total anaerobes and Enterobacteriaceae at days 70 and 100 postweaning, respectively. At day 115 postweaning, GM/non-GM offspring had lower ileal Enterobacteriaceae counts than non-GM/non-GM or GM/GM offspring and lower ileal total anaerobes than pigs on the other treatments. GM maize-fed offspring also had higher ileal total anaerobe counts than non-GM maize-fed offspring, and cecal total anaerobes were lower in non-GM/GM and GM/non-GM offspring than in those from the non-GM/non-GM treatment. The only differences observed for major bacterial phyla using 16S rRNA gene sequencing were that fecal Proteobacteria were less abundant in GM maize-fed sows prior to farrowing and in offspring at weaning, with fecal Firmicutes more abundant in offspring. While other differences occurred, they were not observed consistently in offspring, were mostly encountered for low-abundance, low-frequency bacterial taxa, and were not associated with pathology. Therefore, their biological relevance is questionable. This confirms the lack of adverse effects of GM maize on the intestinal microbiota of pigs, even following transgenerational consumption. PMID:24096421

  17. Sequence-based analysis of the intestinal Microbiota of sows and their offspring fed genetically modified maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt Maize).

    PubMed

    Buzoianu, Stefan G; Walsh, Maria C; Rea, Mary C; Quigley, Lisa; O'Sullivan, Orla; Cotter, Paul D; Ross, R Paul; Gardiner, Gillian E; Lawlor, Peadar G

    2013-12-01

    The aim was to investigate transgenerational effects of feeding genetically modified (GM) maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt maize) to sows and their offspring on maternal and offspring intestinal microbiota. Sows were assigned to either non-GM or GM maize dietary treatments during gestation and lactation. At weaning, offspring were assigned within sow treatment to non-GM or GM maize diets for 115 days, as follows: (i) non-GM maize-fed sow/non-GM maize-fed offspring (non-GM/non-GM), (ii) non-GM maize-fed sow/GM maize-fed offspring (non-GM/GM), (iii) GM maize-fed sow/non-GM maize-fed offspring (GM/non-GM), and (iv) GM maize-fed sow/GM maize-fed offspring (GM/GM). Offspring of GM maize-fed sows had higher counts of fecal total anaerobes and Enterobacteriaceae at days 70 and 100 postweaning, respectively. At day 115 postweaning, GM/non-GM offspring had lower ileal Enterobacteriaceae counts than non-GM/non-GM or GM/GM offspring and lower ileal total anaerobes than pigs on the other treatments. GM maize-fed offspring also had higher ileal total anaerobe counts than non-GM maize-fed offspring, and cecal total anaerobes were lower in non-GM/GM and GM/non-GM offspring than in those from the non-GM/non-GM treatment. The only differences observed for major bacterial phyla using 16S rRNA gene sequencing were that fecal Proteobacteria were less abundant in GM maize-fed sows prior to farrowing and in offspring at weaning, with fecal Firmicutes more abundant in offspring. While other differences occurred, they were not observed consistently in offspring, were mostly encountered for low-abundance, low-frequency bacterial taxa, and were not associated with pathology. Therefore, their biological relevance is questionable. This confirms the lack of adverse effects of GM maize on the intestinal microbiota of pigs, even following transgenerational consumption. PMID:24096421

  18. High-Throughput Sequence-Based Analysis of the Intestinal Microbiota of Weanling Pigs Fed Genetically Modified MON810 Maize Expressing Bacillus thuringiensis Cry1Ab (Bt Maize) for 31 Days

    PubMed Central

    Buzoianu, Stefan G.; Walsh, Maria C.; Rea, Mary C.; O'Sullivan, Orla; Cotter, Paul D.; Ross, R. Paul; Lawlor, Peadar G.

    2012-01-01

    The objective of this study was to investigate if feeding genetically modified (GM) MON810 maize expressing the Bacillus thuringiensis insecticidal protein (Bt maize) had any effects on the porcine intestinal microbiota. Eighteen pigs were weaned at ∼28 days and, following a 6-day acclimatization period, were assigned to diets containing either GM (Bt MON810) maize or non-GM isogenic parent line maize for 31 days (n = 9/treatment). Effects on the porcine intestinal microbiota were assessed through culture-dependent and -independent approaches. Fecal, cecal, and ileal counts of total anaerobes, Enterobacteriaceae, and Lactobacillus were not significantly different between pigs fed the isogenic or Bt maize-based diets. Furthermore, high-throughput 16S rRNA gene sequencing revealed few differences in the compositions of the cecal microbiotas. The only differences were that pigs fed the Bt maize diet had higher cecal abundance of Enterococcaceae (0.06 versus 0%; P < 0.05), Erysipelotrichaceae (1.28 versus 1.17%; P < 0.05), and Bifidobacterium (0.04 versus 0%; P < 0.05) and lower abundance of Blautia (0.23 versus 0.40%; P < 0.05) than pigs fed the isogenic maize diet. A lower enzyme-resistant starch content in the Bt maize, which is most likely a result of normal variation and not due to the genetic modification, may account for some of the differences observed within the cecal microbiotas. These results indicate that Bt maize is well tolerated by the porcine intestinal microbiota and provide additional data for safety assessment of Bt maize. Furthermore, these data can potentially be extrapolated to humans, considering the suitability of pigs as a human model. PMID:22467509

  19. Randomly Detected Genetically Modified (GM) Maize (Zea mays L.) near a Transport Route Revealed a Fragile 45S rDNA Phenotype

    PubMed Central

    Waminal, Nomar Espinosa; Ryu, Ki Hyun; Choi, Sun-Hee; Kim, Hyun Hee

    2013-01-01

    Monitoring of genetically modified (GM) crops has been emphasized to prevent their potential effects on the environment and human health. Monitoring of the inadvertent dispersal of transgenic maize in several fields and transport routes in Korea was carried out by qualitative multiplex PCR, and molecular analyses were conducted to identify the events of the collected GM maize. Cytogenetic investigations through fluorescence in situ hybridization (FISH) of the GM maize were performed to check for possible changes in the 45S rDNA cluster because this cluster was reported to be sensitive to replication and transcription stress. Three GM maize kernels were collected from a transport route near Incheon port, Korea, and each was found to contain NK603, stacked MON863 x NK603, and stacked NK603 x MON810 inserts, respectively. Cytogenetic analysis of the GM maize containing the stacked NK603 x MON810 insert revealed two normal compact 5S rDNA signals, but the 45S rDNA showed a fragile phenotype, demonstrating a “beads-on-a-string” fragmentation pattern, which seems to be a consequence of genetic modification. Implications of the 45S rDNA cluster fragility in GM maize are also discussed. PMID:24040165

  20. Multiplex quantification of 12 European Union authorized genetically modified maize lines with droplet digital polymerase chain reaction.

    PubMed

    Dobnik, David; Spilsberg, Bjørn; Bogožalec Košir, Alexandra; Holst-Jensen, Arne; Žel, Jana

    2015-08-18

    Presence of genetically modified organisms (GMO) in food and feed products is regulated in many countries. The European Union (EU) has implemented a threshold for labeling of products containing more than 0.9% of authorized GMOs per ingredient. As the number of GMOs has increased over time, standard-curve based simplex quantitative polymerase chain reaction (qPCR) analyses are no longer sufficiently cost-effective, despite widespread use of initial PCR based screenings. Newly developed GMO detection methods, also multiplex methods, are mostly focused on screening and detection but not quantification. On the basis of droplet digital PCR (ddPCR) technology, multiplex assays for quantification of all 12 EU authorized GM maize lines (per April first 2015) were developed. Because of high sequence similarity of some of the 12 GM targets, two separate multiplex assays were needed. In both assays (4-plex and 10-plex), the transgenes were labeled with one fluorescence reporter and the endogene with another (GMO concentration = transgene/endogene ratio). It was shown that both multiplex assays produce specific results and that performance parameters such as limit of quantification, repeatability, and trueness comply with international recommendations for GMO quantification methods. Moreover, for samples containing GMOs, the throughput and cost-effectiveness is significantly improved compared to qPCR. Thus, it was concluded that the multiplex ddPCR assays could be applied for routine quantification of 12 EU authorized GM maize lines. In case of new authorizations, the events can easily be added to the existing multiplex assays. The presented principle of quantitative multiplexing can be applied to any other domain. PMID:26169291

  1. [Development and validation of event-specific quantitative PCR method for genetically modified maize LY038].

    PubMed

    Mano, Junichi; Masubuchi, Tomoko; Hatano, Shuko; Futo, Satoshi; Koiwa, Tomohiro; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi

    2013-01-01

    In this article, we report a novel real-time PCR-based analytical method for quantitation of the GM maize event LY038. We designed LY038-specific and maize endogenous reference DNA-specific PCR amplifications. After confirming the specificity and linearity of the LY038-specific PCR amplification, we determined the conversion factor required to calculate the weight-based content of GM organism (GMO) in a multilaboratory evaluation. Finally, in order to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind DNA samples containing LY038 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The precision of the method was evaluated as the RSD of reproducibility (RSDR), and the values obtained were all less than 25%. The limit of quantitation of the method was judged to be 0.5% based on the definition of ISO 24276 guideline. The results from the collaborative trial suggested that the developed quantitative method would be suitable for practical testing of LY038 maize. PMID:23470871

  2. A new PCR-CGE (size and color) method for simultaneous detection of genetically modified maize events.

    PubMed

    Nadal, Anna; Coll, Anna; La Paz, Jose-Luis; Esteve, Teresa; Pla, Maria

    2006-10-01

    We present a novel multiplex PCR assay for simultaneous detection of multiple transgenic events in maize. Initially, five PCR primers pairs specific to events Bt11, GA21, MON810, and NK603, and Zea mays L. (alcohol dehydrogenase) were included. The event specificity was based on amplification of transgene/plant genome flanking regions, i.e., the same targets as for validated real-time PCR assays. These short and similarly sized amplicons were selected to achieve high and similar amplification efficiency for all targets; however, its unambiguous identification was a technical challenge. We achieved a clear distinction by a novel CGE approach that combined the identification by size and color (CGE-SC). In one single step, all five targets were amplified and specifically labeled with three different fluorescent dyes. The assay was specific and displayed an LOD of 0.1% of each genetically modified organism (GMO). Therefore, it was adequate to fulfill legal thresholds established, e.g., in the European Union. Our CGE-SC based strategy in combination with an adequate labeling design has the potential to simultaneously detect higher numbers of targets. As an example, we present the detection of up to eight targets in a single run. Multiplex PCR-CGE-SC only requires a conventional sequencer device and enables automation and high throughput. In addition, it proved to be transferable to a different laboratory. The number of authorized GMO events is rapidly growing; and the acreage of genetically modified (GM) varieties cultivated and commercialized worldwide is rapidly increasing. In this context, our multiplex PCR-CGE-SC can be suitable for screening GM contents in food. PMID:16972302

  3. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method. PMID:25381609

  4. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is provided each year to our stakeholders in the maize genetic community. In this report, we describe the five-year plan for MaizeGDB reviewed in early 2008 by the USDA-ARS peer review process and which was developed with inputs from our Working Group and the Allerton 2007 Report (MNL 82...

  5. Validation of real-time PCR analyses for line-specific quantitation of genetically modified maize and soybean using new reference molecules.

    PubMed

    Shindo, Yoichiro; Kuribara, Hideo; Matsuoka, Takeshi; Futo, Satoshi; Sawada, Chihiro; Shono, Jinji; Akiyama, Hiroshi; Goda, Yukihiro; Toyoda, Masatake; Hino, Akihiro

    2002-01-01

    Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were <13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops. PMID:12374412

  6. Ninety-day oral toxicity studies on two genetically modified maize MON810 varieties in Wistar Han RCC rats (EU 7th Framework Programme project GRACE).

    PubMed

    Zeljenková, Dagmar; Ambrušová, Katarína; Bartušová, Mária; Kebis, Anton; Kovrižnych, Jevgenij; Krivošíková, Zora; Kuricová, Miroslava; Líšková, Aurélia; Rollerová, Eva; Spustová, Viera; Szabová, Elena; Tulinská, Jana; Wimmerová, Soňa; Levkut, Mikuláš; Révajová, Viera; Ševčíková, Zuzana; Schmidt, Kerstin; Schmidtke, Jörg; La Paz, Jose Luis; Corujo, Maria; Pla, Maria; Kleter, Gijs A; Kok, Esther J; Sharbati, Jutta; Hanisch, Carlos; Einspanier, Ralf; Adel-Patient, Karine; Wal, Jean-Michel; Spök, Armin; Pöting, Annette; Kohl, Christian; Wilhelm, Ralf; Schiemann, Joachim; Steinberg, Pablo

    2014-12-01

    The GMO Risk Assessment and Communication of Evidence (GRACE; www.grace-fp7.eu ) project is funded by the European Commission within the 7th Framework Programme. A key objective of GRACE is to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of two 90-day feeding trials with two different GM maize MON810 varieties, their near-isogenic non-GM varieties and four additional conventional maize varieties are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 408. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after subchronic exposure, independently of the two different genetic backgrounds of the event. PMID:25270621

  7. Event specific qualitative and quantitative polymerase chain reaction detection of genetically modified MON863 maize based on the 5'-transgene integration sequence.

    PubMed

    Yang, Litao; Xu, Songci; Pan, Aihu; Yin, Changsong; Zhang, Kewei; Wang, Zhenying; Zhou, Zhigang; Zhang, Dabing

    2005-11-30

    Because of the genetically modified organisms (GMOs) labeling policies issued in many countries and areas, polymerase chain reaction (PCR) methods were developed for the execution of GMO labeling policies, such as screening, gene specific, construct specific, and event specific PCR detection methods, which have become a mainstay of GMOs detection. The event specific PCR detection method is the primary trend in GMOs detection because of its high specificity based on the flanking sequence of the exogenous integrant. This genetically modified maize, MON863, contains a Cry3Bb1 coding sequence that produces a protein with enhanced insecticidal activity against the coleopteran pest, corn rootworm. In this study, the 5'-integration junction sequence between the host plant DNA and the integrated gene construct of the genetically modified maize MON863 was revealed by means of thermal asymmetric interlaced-PCR, and the specific PCR primers and TaqMan probe were designed based upon the revealed 5'-integration junction sequence; the conventional qualitative PCR and quantitative TaqMan real-time PCR detection methods employing these primers and probes were successfully developed. In conventional qualitative PCR assay, the limit of detection (LOD) was 0.1% for MON863 in 100 ng of maize genomic DNA for one reaction. In the quantitative TaqMan real-time PCR assay, the LOD and the limit of quantification were eight and 80 haploid genome copies, respectively. In addition, three mixed maize samples with known MON863 contents were detected using the established real-time PCR systems, and the ideal results indicated that the established event specific real-time PCR detection systems were reliable, sensitive, and accurate. PMID:16302741

  8. Selection of Suitable DNA Extraction Methods for Genetically Modified Maize 3272, and Development and Evaluation of an Event-Specific Quantitative PCR Method for 3272.

    PubMed

    Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2016-01-01

    A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize, 3272. We first attempted to obtain genome DNA from this maize using a DNeasy Plant Maxi kit and a DNeasy Plant Mini kit, which have been widely utilized in our previous studies, but DNA extraction yields from 3272 were markedly lower than those from non-GM maize seeds. However, lowering of DNA extraction yields was not observed with GM quicker or Genomic-tip 20/G. We chose GM quicker for evaluation of the quantitative method. We prepared a standard plasmid for 3272 quantification. The conversion factor (Cf), which is required to calculate the amount of a genetically modified organism (GMO), was experimentally determined for two real-time PCR instruments, the Applied Biosystems 7900HT (the ABI 7900) and the Applied Biosystems 7500 (the ABI7500). The determined Cf values were 0.60 and 0.59 for the ABI 7900 and the ABI 7500, respectively. To evaluate the developed method, a blind test was conducted as part of an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSDr). The determined values were similar to those in our previous validation studies. The limit of quantitation for the method was estimated to be 0.5% or less, and we concluded that the developed method would be suitable and practical for detection and quantification of 3272. PMID:26936302

  9. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations.

    PubMed

    Devos, Yann; Meihls, Lisa N; Kiss, József; Hibbard, Bruce E

    2013-04-01

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified Bt-maize offers an additional management tool for WCR and has been valuable in reducing insecticide use and increasing farm income. A concern is that the widespread, repeated, and exclusive deployment of the same Bt-maize transformation event will result in the rapid evolution of resistance in WCR. This publication explores the potential of WCR to evolve resistance to plant-produced Bt-toxins from the first generation of Diabrotica-active Bt-maize events (MON 863 and MON 88017, DAS-59122-7 and MIR604), and whether currently implemented risk management strategies to delay and monitor resistance evolution are appropriate. In twelve of the twelve artificial selection experiments reported, resistant WCR populations were yielded rapidly. Field-selected resistance of WCR to Cry3Bb1 is documented in some US maize growing areas, where an increasing number of cases of unexpected damage of WCR larvae to Bt-maize MON 88017 has been reported. Currently implemented insect resistance management measures for Bt-crops usually rely on the high dose/refuge (HDR) strategy. Evidence (including laboratory, greenhouse and field data) indicates that several conditions contributing to the success of the HDR strategy may not be met for the first generation of Bt-maize events and WCR: (1) the Bt-toxins are expressed heterogeneously at a low-to-moderate dose in roots; (2) resistance alleles may be present at a higher frequency than initially assumed; (3) WCR may mate in a non-random manner; (4) resistance traits could have non-recessive inheritance; and (5) fitness costs may not necessarily be associated with resistance evolution. However, caution must be exercised when extrapolating laboratory and greenhouse results to field conditions. Model predictions suggest that a 20 % refuge of non-Diabrotica-active Bt-maize can delay resistance evolution in WCR under certain conditions. This publication concludes that further research is needed to resolve the remaining scientific uncertainty related to the appropriateness of the HDR in delaying resistance evolution in WCR, resistance monitoring is essential to detect early warning signs indicating resistance evolution in the field, and that integrated pest management reliant on multiple tactics should be deployed to ensure effective long-term corn rootworm management and sustainable use of Bt-maize. PMID:23011587

  10. Interlaboratory transfer of a PCR multiplex method for simultaneous detection of four genetically modified maize lines: Bt11, MON810, T25, and GA21.

    PubMed

    Hernández, Marta; Rodríguez-Lázaro, David; Zhang, David; Esteve, Teresa; Pla, Maria; Prat, Salomé

    2005-05-01

    The number of cultured hectares and commercialized genetically modified organisms (GMOs) has increased exponentially in the past 9 years. Governments in many countries have established a policy of labeling all food and feed containing or produced by GMOs. Consequently, versatile, laboratory-transferable GMO detection methods are in increasing demand. Here, we describe a qualitative PCR-based multiplex method for simultaneous detection and identification of four genetically modified maize lines: Bt11, MON810, T25, and GA21. The described system is based on the use of five primers directed to specific sequences in these insertion events. Primers were used in a single optimized multiplex PCR reaction, and sequences of the amplified fragments are reported. The assay allows amplification of the MON810 event from the 35S promoter to the hsp intron yielding a 468 bp amplicon. Amplification of the Bt11 and T25 events from the 35S promoter to the PAT gene yielded two different amplicons of 280 and 177 bp, respectively, whereas amplification of the 5' flanking region of the GA21 gave rise to an amplicon of 72 bp. These fragments are clearly distinguishable in agarose gels and have been reproduced successfully in a different laboratory. Hence, the proposed method comprises a rapid, simple, reliable, and sensitive (down to 0.05%) PCR-based assay, suitable for detection of these four GM maize lines in a single reaction. PMID:15853368

  11. Development and Interlaboratory Validation of a Simple Screening Method for Genetically Modified Maize Using a ΔΔCq-Based Multiplex Real-Time PCR Assay.

    PubMed

    Noguchi, Akio; Nakamura, Kosuke; Sakata, Kozue; Sato-Fukuda, Nozomi; Ishigaki, Takumi; Mano, Junichi; Takabatake, Reona; Kitta, Kazumi; Teshima, Reiko; Kondo, Kazunari; Nishimaki-Mogami, Tomoko

    2016-04-19

    A number of genetically modified (GM) maize events have been developed and approved worldwide for commercial cultivation. A screening method is needed to monitor GM maize approved for commercialization in countries that mandate the labeling of foods containing a specified threshold level of GM crops. In Japan, a screening method has been implemented to monitor approved GM maize since 2001. However, the screening method currently used in Japan is time-consuming and requires generation of a calibration curve and experimental conversion factor (Cf) value. We developed a simple screening method that avoids the need for a calibration curve and Cf value. In this method, ΔCq values between the target sequences and the endogenous gene are calculated using multiplex real-time PCR, and the ΔΔCq value between the analytical and control samples is used as the criterion for determining analytical samples in which the GM organism content is below the threshold level for labeling of GM crops. An interlaboratory study indicated that the method is applicable independently with at least two models of PCR instruments used in this study. PMID:27010783

  12. [Laboratory-performance study of the notified methods to detect genetically modified maize (CBH351) and potato (NewLeaf Plus and NewLeaf Y)].

    PubMed

    Watanabe, Takahiro; Kasama, Kikuko; Wakui, Chiseko; Shibuya, Masaaki; Matsuki, Akihiko; Akiyama, Hiroshi; Maitani, Tamio

    2003-12-01

    To investigate the key factors affecting the reliability of the analytical results, a laboratory-performance study was attempted for the notified methods to detect genetically modified (GM) maize (CBH351) and GM potato (NewLeaf Plus and NewLeaf Y). The test samples were designed as three pairs of blind duplicates, which included 0%, 0.1% and 1.0% GM maize (CBH351) or GM potato (NewLeaf Plus or NewLeaf Y). Fourteen laboratories participated in the study. The test samples were sent to the participating laboratories along with the protocol. The data were collected from all laboratories and statistically analyzed. For the 0% sample of the CBH351 maize, one laboratory reported a false-positive result. It was considered that contamination could have occurred via the common use of equipment or tools for the test. For the 0.1% samples of the NewLeaf Plus potato or NewLeaf Y potato, on the other hand, three laboratories reported false-negative results. It was presumed that these results were due to changes of the conditions of the electrophoresis and agarose-gel staining. The other laboratories reported appropriate results. It was considered that the method employed in this study was suitable for the assessment of laboratory performance. PMID:15038109

  13. Transportable data from non-target arthropod field studies for the environmental risk assessment of genetically modified maize expressing an insecticidal double-stranded RNA.

    PubMed

    Ahmad, Aqeel; Negri, Ignacio; Oliveira, Wladecir; Brown, Christopher; Asiimwe, Peter; Sammons, Bernard; Horak, Michael; Jiang, Changjian; Carson, David

    2016-02-01

    As part of an environmental risk assessment, the potential impact of genetically modified (GM) maize MON 87411 on non-target arthropods (NTAs) was evaluated in the field. MON 87411 confers resistance to corn rootworm (CRW; Diabrotica spp.) by expressing an insecticidal double-stranded RNA (dsRNA) transcript and the Cry3Bb1 protein and tolerance to the herbicide glyphosate by producing the CP4 EPSPS protein. Field trials were conducted at 14 sites providing high geographic and environmental diversity within maize production areas from three geographic regions including the U.S., Argentina, and Brazil. MON 87411, the conventional control, and four commercial conventional reference hybrids were evaluated for NTA abundance and damage. Twenty arthropod taxa met minimum abundance criteria for valid statistical analysis. Nine of these taxa occurred in at least two of the three regions and in at least four sites across regions. These nine taxa included: aphid, predatory earwig, lacewing, ladybird beetle, leafhopper, minute pirate bug, parasitic wasp, sap beetle, and spider. In addition to wide regional distribution, these taxa encompass the ecological functions of herbivores, predators and parasitoids in maize agro-ecosystems. Thus, the nine arthropods may serve as representative taxa of maize agro-ecosystems, and thereby support that analysis of relevant data generated in one region can be transportable for the risk assessment of the same or similar GM crop products in another region. Across the 20 taxa analyzed, no statistically significant differences in abundance were detected between MON 87411 and the conventional control for 123 of the 128 individual-site comparisons (96.1 %). For the nine widely distributed taxa, no statistically significant differences in abundance were detected between MON 87411 and the conventional control. Furthermore, no statistically significant differences were detected between MON 87411 and the conventional control for 53 out of 56 individual-site comparisons (94.6 %) of NTA pest damage to the crop. In each case where a significant difference was observed in arthropod abundance or damage, the mean value for MON 87411 was within the reference range and/or the difference was not consistently observed across collection methods and/or sites. Thus, the differences were not representative of an adverse effect unfamiliar to maize and/or were not indicative of a consistent plant response associated with the GM traits. Results from this study support a conclusion of no adverse environmental impact of MON 87411 on NTAs compared to conventional maize and demonstrate the utility of relevant transportable data across regions for the ERA of GM crops. PMID:26433587

  14. MAIZEGDB, THE MAIZE GENETICS AND GENOMICS DATABASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the database that houses data and analysis tools crafted to suit the needs of the community of maize geneticists. Among the data sets included in MaizeGDB are sequences; detailed genetic, physical, recombination nodule, and cytological maps; molecular markers; a...

  15. MaizeGDB: The Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genetic, genomic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website...

  16. Genetic mechanisms of Maize dwarf mosaic virus resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize resistance to viruses has been well-characterized at the genetic level, and loci responsible for resistance to potyviruses including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), have been mapped in several ge...

  17. MaizeGDB: The Maize Genetics and Genomics Database.

    PubMed

    Harper, Lisa; Gardiner, Jack; Andorf, Carson; Lawrence, Carolyn J

    2016-01-01

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website ( http://www.maizegdb.org ) are custom interfaces enabling researchers to browse data and to seek out specific information matching explicit search criteria. In addition, pre-compiled reports are made available for particular types of data and bulletin boards are provided to facilitate communication and coordination among members of the community of maize geneticists. PMID:26519406

  18. Answers to critics: Why there is a long term toxicity due to a Roundup-tolerant genetically modified maize and to a Roundup herbicide.

    PubMed

    Séralini, Gilles-Eric; Mesnage, Robin; Defarge, Nicolas; Gress, Steeve; Hennequin, Didier; Clair, Emilie; Malatesta, Manuela; de Vendômois, Joël Spiroux

    2013-03-01

    Our recent work (Séralini et al., 2012) remains to date the most detailed study involving the life-long consumption of an agricultural genetically modified organism (GMO). This is true especially for NK603 maize for which only a 90-day test for commercial release was previously conducted using the same rat strain (Hammond et al., 2004). It is also the first long term detailed research on mammals exposed to a highly diluted pesticide in its total formulation with adjuvants. This may explain why 75% of our first criticisms arising within a week, among publishing authors, come from plant biologists, some developing patents on GMOs, even if it was a toxicological paper on mammals, and from Monsanto Company who owns both the NK603 GM maize and Roundup herbicide (R). Our study has limits like any one, and here we carefully answer to all criticisms from agencies, consultants and scientists, that were sent to the Editor or to ourselves. At this level, a full debate is biased if the toxicity tests on mammals of NK603 and R obtained by Monsanto Company remain confidential and thus unavailable in an electronic format for the whole scientific community to conduct independent scrutiny of the raw data. In our article, the conclusions of long-term NK603 and Roundup toxicities came from the statistically highly discriminant findings at the biochemical level in treated groups in comparison to controls, because these findings do correspond in an blinded analysis to the pathologies observed in organs, that were in turn linked to the deaths by anatomopathologists. GM NK603 and R cannot be regarded as safe to date. PMID:23146697

  19. Subchronic feeding study with genetically modified stacked trait lepidopteran and coleopteran resistant (DAS-157-1xDAS-59122-7) maize grain in Sprague-Dawley rats.

    PubMed

    Appenzeller, Laura M; Malley, Linda; Mackenzie, Susan A; Hoban, Denise; Delaney, Bryan

    2009-07-01

    DAS-157-1xDAS-59122-7 (1507x59122) is a genetically modified (GM) maize hybrid that was produced by crossing of two GM maize inbreds; DAS-157-1 and DAS-59122-7. This hybrid cross expresses four transgenic proteins: Cry1F and PAT (from DAS-157-1) and Cry34Ab1/Cry35Ab1 and PAT (from DAS-59122-7) that confer resistance to lepidopteran and coleopteran pests and tolerance to the herbicidal active ingredient glufosinate-ammonium. The current subchronic feeding study was conducted in Sprague-Dawley rats to evaluate the potential health effects of long-term consumption of a rodent diet containing 1507x59122 maize grain compared with a diet containing maize grain from its near-isogenic control (091). Diets formulated with three unrelated non-GM commercial hybrids (3573, 35P12, 36G12) were also included for within study reference data. All diets contained 34% (w/wt) maize grain and were prepared according to the specifications of PMI((R)) Nutrition International, LLC Certified Rodent LabDiet((R)) 5002 (PMI((R)) 5002). Diets were fed ad libitum to rats for at least 92days. OECD 408 response variables from rats fed the 1507x59122 diet were compared with those from rats fed the 091 control diet. No toxicologically significant differences were observed in nutritional performance variables, clinical and neurobehavioral signs, ophthalmology, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis), organ weights, and gross and microscopic pathology between rats in the 091 and 1507x59122 treatment groups. The results from this study demonstrate that 1507x59122 maize grain is as safe and nutritious as non-GM maize grain and support the concept that crossing of two safe GM maize events results in production of a safe stacked GM event. PMID:19358870

  20. Development, Optimization, and Evaluation of a Duplex Droplet Digital PCR Assay To Quantify the T-nos/hmg Copy Number Ratio in Genetically Modified Maize.

    PubMed

    Félix-Urquídez, Dalmira; Pérez-Urquiza, Melina; Valdez Torres, José-Benigno; León-Félix, Josefina; García-Estrada, Raymundo; Acatzi-Silva, Abraham

    2016-01-01

    Certified reference materials (CRMs) are required to guarantee the reliability of analytical measurements. The CRMs available in the field of genetically modified organisms (GMOs) are characterized using real-time polymerase chain reaction (qPCR). This technology has limited application, because of its dependence on a calibrant. The objective of this study was to obtain a method with higher metrological quality, to characterize the CRMs for their contents of T-nos/hmg copy number ratio in maize. A duplex droplet digital PCR (ddPCR) assay was developed and optimized by a central composite design. The developed method achieved an absolute limit of detection (LOD) of 11 cP T-nos, a relative LOD of 0.034%, a limit of quantification (LOQ) of 23 cP (relative LOQ of 0.08%), and a dynamic range of 0.08%-100% T-nos/hmg ratio. The specificity and applicability of the assay were established for the analysis of low T-nos concentrations (0.9%) in several corn varieties. The convenience of DNA digestion to reduce measurement bias in the case of multiple-copy binding was confirmed through an enzymatic restriction assay. Given its overall performance, this method can be used to characterize CRM candidates for their contents of T-nos/hmg ratio. PMID:26605751

  1. Rapid visual detection of phytase gene in genetically modified maize using loop-mediated isothermal amplification method.

    PubMed

    Huang, Xin; Chen, Lili; Xu, Jiangmin; Ji, Hai-Feng; Zhu, Shuifang; Chen, Hongjun

    2014-08-01

    Transgenic maize plant expressing high phytase activity has been reported and approved by Chinese government in 2009. Here, we report a highly specific loop-mediated isothermal amplification (LAMP) method to detect the phytase gene in the GMO maize. The LAMP reaction takes less than 20min and the amplification is visible without gel electrophoresis. The detection sensitivity of the LAMP method is about 30 copies of phytase genomic DNA, which is 33.3 times greater than the conventional PCR method with gel electrophoresis. The quantitative detection results showed that the LAMP method has a good linear correlation between the DNA copy number and the associated Tt values over a large dynamic range of template concentration from 6×10(1) to 6×10(7) copies, with a quantification limit of 60 copies. Therefore, the LAMP method is visual, faster, and more sensitive, and does not need special equipment compared to traditional PCR technique, which is very useful for field tests and fast screening of GMO feeds. PMID:24629956

  2. New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity.

    PubMed

    Séralini, Gilles-Eric; Cellier, Dominique; de Vendomois, Joël Spiroux

    2007-05-01

    Health risk assessment of genetically modified organisms (GMOs) cultivated for food or feed is under debate throughout the world, and very little data have been published on mid- or long-term toxicological studies with mammals. One of these studies performed under the responsibility of Monsanto Company with a transgenic corn MON863 has been subjected to questions from regulatory reviewers in Europe, where it was finally approved in 2005. This necessitated a new assessment of kidney pathological findings, and the results remained controversial. An Appeal Court action in Germany (Münster) allowed public access in June 2005 to all the crude data from this 90-day rat-feeding study. We independently re-analyzed these data. Appropriate statistics were added, such as a multivariate analysis of the growth curves, and for biochemical parameters comparisons between GMO-treated rats and the controls fed with an equivalent normal diet, and separately with six reference diets with different compositions. We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24-40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively); urine phosphorus and sodium excretions diminished in males by 31-35% (week 14, dose 33%) for the most important results significantly linked to the treatment in comparison to seven diets tested. Longer experiments are essential in order to indicate the real nature and extent of the possible pathology; with the present data it cannot be concluded that GM corn MON863 is a safe product. PMID:17356802

  3. THE MAIZE GENETICS AND GENOMICS DATABASE: A COMMUNITY RESOURCE FOR ACCESS TO DIVERSE MAIZE DATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (the Maize Genetics and Genomics Database) is the research database for the maize community. The site features a wealth of resources and data facilitating the scientific study of maize. Among the data sets included in MaizeGDB are sequences, including PlantGDB's EST and GSS contig assemblie...

  4. MAIZEGDB: THE MAIZE COMMUNITY GENETICS AND GENOMICS DATABASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (Maize Genetics and Genomics Database) is the research database for the maize community. The site features a wealth of resources and data facilitating the scientific study of maize. Among the data sets included in MaizeGDB are sequences, including integration with various contig assemblies;...

  5. The genetic architecture of maize height.

    PubMed

    Peiffer, Jason A; Romay, Maria C; Gore, Michael A; Flint-Garcia, Sherry A; Zhang, Zhiwu; Millard, Mark J; Gardner, Candice A C; McMullen, Michael D; Holland, James B; Bradbury, Peter J; Buckler, Edward S

    2014-04-01

    Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in >64,500 plots across 13 environments. These plots contained >7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be >90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of height variation. The effects of two tropical alleles at this QTL were independently validated by fine mapping in NIL families. Several significant associations found by GWAS colocalized with established height loci, including brassinosteroid-deficient dwarf1, dwarf plant1, and semi-dwarf2. GBLUP explained >80% of height variation in the panels and outperformed bootstrap aggregation of family-nested QTL models in evaluations of prediction accuracy. These results revealed maize height was under strong genetic control and had a highly polygenic genetic architecture. They also showed that multiple models of genetic architecture differing in polygenicity and effect sizes can plausibly explain a population's variation in maize height, but they may vary in predictive efficacy. PMID:24514905

  6. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2007 report for MaizeGDB lists the new hires who will focus on curation/outreach and the genome sequence, respectively. Currently all sequence in the database comes from a PlantGDB pipeline and is presented with deep links to external resources such as PlantGDB, Dana Farber, GenBank, the Arizona...

  7. The 50th Annual Maize Genetics Conference

    SciTech Connect

    Cone, Karen

    2014-03-26

    The 50th Annual Maize Genetics Conference was held February 27 - March 2, 2008 at the Marriott Wardman Park Hotel in Washington, D.C. As the golden anniversary of the Conference and coinciding with the release of a draft of the maize genome sequence, this was a special meeting. To publicize this unique occasion, meeting organizers hosted a press conference, which was attended by members of the press representing science and non-science publications, and an evening reception at the Smithsonian National Museum of Natural History, where the draft sequence was announced and awards were presented to Dr. Mary Clutter and Senator Kit Bond to thank them for their outstanding contributions to maize genetics and genomics research. As usual, the Conference provided an invigorating forum for exchange of recent research results in many areas of maize genetics, e.g., cytogenetics, development, molecular genetics, transposable element biology, biochemical genetics, and genomics. Results were shared via both oral and poster presentations. Invited talks were given by four distinguished geneticists: Vicki Chandler, University of Arizona; John Doebley, University of Wisconsin; Susan Wessler, University of Georgia; and Richard Wilson, Washington University. There were 46 short talks and 241 poster presentations. The Conference was attended by over 500 participants. This included a large number of first-time participants in the meeting and an increasingly visible presence by individuals from underrepresented groups. Although we do not have concrete counts, there seem to be more African American, African and Hispanic/Latino attendees coming to the meeting than in years past. In addition, this meeting attracted many participants from outside the U.S. Student participation continues to be hallmark of the spirit of free exchange and cooperation characteristic of the maize genetics community. With the generous support provided by DOE, USDA NSF, and corporate/private donors, organizers were able to defray lodging and meal costs for 133 graduate and undergraduate students and 66 postdocs

  8. The genetic architecture of maize flowering time.

    PubMed

    Buckler, Edward S; Holland, James B; Bradbury, Peter J; Acharya, Charlotte B; Brown, Patrick J; Browne, Chris; Ersoz, Elhan; Flint-Garcia, Sherry; Garcia, Arturo; Glaubitz, Jeffrey C; Goodman, Major M; Harjes, Carlos; Guill, Kate; Kroon, Dallas E; Larsson, Sara; Lepak, Nicholas K; Li, Huihui; Mitchell, Sharon E; Pressoir, Gael; Peiffer, Jason A; Rosas, Marco Oropeza; Rocheford, Torbert R; Romay, M Cinta; Romero, Susan; Salvo, Stella; Sanchez Villeda, Hector; da Silva, H Sofia; Sun, Qi; Tian, Feng; Upadyayula, Narasimham; Ware, Doreen; Yates, Heather; Yu, Jianming; Zhang, Zhiwu; Kresovich, Stephen; McMullen, Michael D

    2009-08-01

    Flowering time is a complex trait that controls adaptation of plants to their local environment in the outcrossing species Zea mays (maize). We dissected variation for flowering time with a set of 5000 recombinant inbred lines (maize Nested Association Mapping population, NAM). Nearly a million plants were assayed in eight environments but showed no evidence for any single large-effect quantitative trait loci (QTLs). Instead, we identified evidence for numerous small-effect QTLs shared among families; however, allelic effects differ across founder lines. We identified no individual QTLs at which allelic effects are determined by geographic origin or large effects for epistasis or environmental interactions. Thus, a simple additive model accurately predicts flowering time for maize, in contrast to the genetic architecture observed in the selfing plant species rice and Arabidopsis. PMID:19661422

  9. Expanding maize genetic resources with predomestication alleles: maize-teosinte introgression populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teosinte (Zea mays ssp. parviglumis) has greater genetic diversity than maize inbreds and landraces (Z. mays ssp. mays). There are, however, limited genetic resources to efficiently evaluate and tap this diversity. To broaden resources for genetic diversity studies in maize, we developed and evaluat...

  10. MAIZE GDB: THE MAIZE GENETICS AND GENOMICS DATABASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three exercises are presented to familiarize workshop participants with how to use the MaizeGDB website. The first exercise guides the student through the online MaizeGDB Tutorial and asks questions that can only be answered by having completed the exercise. The second exercise uses the MaizeGDB w...

  11. Use of Mutant-Assisted Gene Identification and Characterization (MAGIC) to identify novel genetic loci that modify the maize hypersensitive response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The partially-dominant, autoactive maize disease resistance gene Rp1-D21 causes hypersensitive response (HR) lesions to form spontaneously on the leaves and stem in the absence of pathogen recognition. The maize nested association mapping (NAM) population consists of 25 200-line subpopulations each...

  12. Entering the second century of maize quantitative genetics

    PubMed Central

    Wallace, J G; Larsson, S J; Buckler, E S

    2014-01-01

    Maize is the most widely grown cereal in the world. In addition to its role in global agriculture, it has also long served as a model organism for genetic research. Maize stands at a genetic crossroads, as it has access to all the tools available for plant genetics but exhibits a genetic architecture more similar to other outcrossing organisms than to self-pollinating crops and model plants. In this review, we summarize recent advances in maize genetics, including the development of powerful populations for genetic mapping and genome-wide association studies (GWAS), and the insights these studies yield on the mechanisms underlying complex maize traits. Most maize traits are controlled by a large number of genes, and linkage analysis of several traits implicates a ‘common gene, rare allele' model of genetic variation where some genes have many individually rare alleles contributing. Most natural alleles exhibit small effect sizes with little-to-no detectable pleiotropy or epistasis. Additionally, many of these genes are locked away in low-recombination regions that encourage the formation of multi-gene blocks that may underlie maize's strong heterotic effect. Domestication left strong marks on the maize genome, and some of the differences in trait architectures may be due to different selective pressures over time. Overall, maize's advantages as a model system make it highly desirable for studying the genetics of outcrossing species, and results from it can provide insight into other such species, including humans. PMID:23462502

  13. The art and design of genetic screens: maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) is an excellent model for basic research. Genetic screens have informed our understanding of developmental processes, meiosis, epigenetics and biochemical pathways--not only in maize but also in other cereal crops. We discuss the forward and reverse genetic screens that are possible...

  14. Genetic erosion in maize's center of origin.

    PubMed

    Dyer, George A; López-Feldman, Alejandro; Yúnez-Naude, Antonio; Taylor, J Edward

    2014-09-30

    Crop genetic diversity is an indispensable resource for farmers and professional breeders responding to changing climate, pests, and diseases. Anecdotal appraisals in centers of crop origin have suggested serious threats to this diversity for over half a century. However, a nationwide inventory recently found all maize races previously described for Mexico, including some formerly considered nearly extinct. A flurry of social studies seems to confirm that farmers maintain considerable diversity. Here, we compare estimates of maize diversity from case studies over the past 15 y with nationally and regionally representative matched longitudinal data from farmers across rural Mexico. Our findings reveal an increasing bias in inferences based on case study results and widespread loss of diversity. Cross-sectional, case study data suggest that farm-level richness has increased by 0.04 y(-1) nationwide; however, direct estimates using matched longitudinal data reveal that richness dropped -0.04 y(-1) between 2002 and 2007, from 1.43 to 1.22 varieties per farm. Varietal losses occurred across regions and altitudinal zones, and regardless of farm turnover within the sector. Extinction of local maize populations may not have resulted in an immediate loss of alleles, but low varietal richness and changes in maize's metapopulation dynamics may prevent farmers from accessing germplasm suitable to a rapidly changing climate. Declining yields could then lead farmers to leave the sector and result in a further loss of diversity. Similarities in research approaches across crops suggest that methodological biases could conceal a loss of diversity at other centers of crop origin. PMID:25197088

  15. Genetic control of leaf curl in maize.

    PubMed

    Entringer, G C; Guedes, F L; Oliveira, A A; Nascimento, J P; Souza, J C

    2014-01-01

    Among the many implications of climatic change on agriculture, drought is expected to continue to have a major impact on agribusinesses. Leaf curling is an anatomical characteristic that might be potentially used to enhance plant tolerance to water deficit. Hence, we aimed to study the genetic control of leaf curl in maize. From 2 contrasting inbred lines for the trait, generations F1, F2, and the backcrosses were obtained. All of these generations were evaluated in a randomized block design with 2 replicates. Leaf curl samples were collected from 3 leaves above the first ear at the tasseling stage, and quantified by dividing the width of the leaf blade with natural curling against its extended width. The mean and variance components were estimated by the weighted least square method. It was found that the trait studied has predominance of the additive effects, with genetic control being attributed to few genes that favor selection and exhibit minimal influence from the environment. PMID:24535902

  16. The Other NPGS Maize Collection – A Rich Source of Maize Genetic Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize collection at the North Central Regional Plant Introduction Station, Ames, IA is comprised of over 18,300 accessions from all over the world. Of these, 16,000 are maize accessions with population level genetic diversity and over 2,000 are inbred lines with little segregation. The collectio...

  17. Genetically modified bacteriophages.

    PubMed

    Sagona, Antonia P; Grigonyte, Aurelija M; MacDonald, Paul R; Jaramillo, Alfonso

    2016-04-18

    Phages or bacteriophages, viruses that infect and replicate inside bacteria, are the most abundant microorganisms on earth. The realization that antibiotic resistance poses a substantial risk to the world's health and global economy is revitalizing phage therapy as a potential solution. The increasing ease by which phage genomes can be modified, owing to the influx of new technologies, has led to an expansion of their natural capabilities, and a reduced dependence on phage isolation from environmental sources. This review will discuss the way synthetic biology has accelerated the construction of genetically modified phages and will describe the wide range of their applications. It will further provide insight into the societal and economic benefits that derive from the use of recombinant phages in various sectors, from health to biodetection, biocontrol and the food industry. PMID:26906932

  18. Breeding Specialty Starch Maize Using Exotic Genetic Resources for Gene Discovery of Novel Alleles and Modifiers with Materials Generated from the USDA-ARS GEM Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amylomaize VII, a class of High Amylose Maize with at least 70% of the kernel starch composed of the linear amylose polymer, has had numerous food and industrial applications including the manufacturing of biodegradable plastics, adhesives and candies. More recently it has been found to be a signi...

  19. Maize centromere mapping: A comparison of physical and genetic strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The location of chromosome centromeres in various maize genetic maps relative to physical maps has not been consistently and clearly identified due to the paucity of markers and low recombination in the highly heterochromatic centromeric and flanking regions. Centromere positions on seven maize chro...

  20. Genetic Properties of the Maize Nested Association Mapping Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the world’s most diverse species, and this variation can be used to understand the molecular basis of phenotypic variation and to improve agricultural efficiency and sustainability. To access this genetic variation, 25 diverse inbred maize lines were crossed to the B73 reference lin...

  1. The Genetic Architecture of Maize Flowering Time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering time is the key trait controlling adaptation of plants to their local environment, and, in an outcrossing species like maize, it is a complex trait. Variation for this complex trait was dissected in maize using a novel set of 5000 recombinant inbred lines (maize Nested Association Mapping...

  2. Application of capillary electrophoretic chips in protein profiling of plant extracts for identification of genetic modifications of maize.

    PubMed

    Poboży, Ewa; Filaber, Monika; Koc, Anna; Garcia-Reyes, Juan F

    2013-09-01

    In this study, the chip gel electrophoresis with LIF detection was applied in protein profiling of fractionated and total extracts of maize standards. The sensitivity of such determinations can be enhanced by lyophilization of extracts or employing filtering and preconcentration with cutoff filters. Combinatorial peptide ligand library applied for sample processing prior to the electrophoretic analysis was, especially, an effective pretreatment step in the determination of low-abundance proteins. Several repeatable differences were observed for protein profiles between maize standards not containing the genetically modified organisms (GMOs) and those containing GMO, which can be potentially employed for identification of GMO in maize samples and foods of maize origin. PMID:23856913

  3. Genome-wide genetic changes during modern breeding of maize.

    PubMed

    Jiao, Yinping; Zhao, Hainan; Ren, Longhui; Song, Weibin; Zeng, Biao; Guo, Jinjie; Wang, Baobao; Liu, Zhipeng; Chen, Jing; Li, Wei; Zhang, Mei; Xie, Shaojun; Lai, Jinsheng

    2012-07-01

    The success of modern maize breeding has been demonstrated by remarkable increases in productivity over the last four decades. However, the underlying genetic changes correlated with these gains remain largely unknown. We report here the sequencing of 278 temperate maize inbred lines from different stages of breeding history, including deep resequencing of 4 lines with known pedigree information. The results show that modern breeding has introduced highly dynamic genetic changes into the maize genome. Artificial selection has affected thousands of targets, including genes and non-genic regions, leading to a reduction in nucleotide diversity and an increase in the proportion of rare alleles. Genetic changes during breeding happen rapidly, with extensive variation (SNPs, indels and copy-number variants (CNVs)) occurring, even within identity-by-descent regions. Our genome-wide assessment of genetic changes during modern maize breeding provides new strategies as well as practical targets for future crop breeding and biotechnology. PMID:22660547

  4. Metabolite profiling of maize kernels--genetic modification versus environmental influence.

    PubMed

    Frank, Thomas; Röhlig, Richard M; Davies, Howard V; Barros, Eugenia; Engel, Karl-Heinz

    2012-03-28

    A metabolite profiling approach based on gas chromatography-mass spectrometry (GC-MS) was applied to investigate the metabolite profiles of genetically modified (GM) Bt-maize (DKC78-15B, TXP 138F) and Roundup Ready-maize (DKC78-35R). For the comparative investigation of the impact of genetic modification versus environmental influence on the metabolite profiles, GM maize was grown together with the non-GM near-isogenic comparators under different environmental conditions, including several growing locations and seasons in Germany and South Africa. Analyses of variance (ANOVA) revealed significant differences between GM and non-GM maize grown in Germany and South Africa. For the factor genotype, 4 and 3%, respectively, of the total number of peaks detected by GC-MS showed statistically significant differences (p < 0.01) in peak heights as compared to the respective isogenic lines. However, ANOVA for the factor environment (growing location, season) revealed higher numbers of significant differences (p < 0.01) between the GM and the non-GM maize grown in Germany (42%) and South Africa (10%), respectively. This indicates that the majority of differences observed are related to natural variability rather than to the genetic modifications. In addition, multivariate data assessment by means of principal component analysis revealed that environmental factors, that is, growing locations and seasons, were dominant parameters driving the variability of the maize metabolite profiles. PMID:22375597

  5. The Genetic Architecture of Maize Stalk Strength

    PubMed Central

    Peiffer, Jason A.; Flint-Garcia, Sherry A.; De Leon, Natalia; McMullen, Michael D.; Kaeppler, Shawn M.; Buckler, Edward S.

    2013-01-01

    Stalk strength is an important trait in maize (Zea mays L.). Strong stalks reduce lodging and maximize harvestable yield. Studies show rind penetrometer resistance (RPR), or the force required to pierce a stalk rind with a spike, is a valid approximation of strength. We measured RPR across 4,692 recombinant inbreds (RILs) comprising the maize nested association mapping (NAM) panel derived from crosses of diverse inbreds to the inbred, B73. An intermated B73×Mo17 family (IBM) of 196 RILs and a panel of 2,453 diverse inbreds from the North Central Regional Plant Introduction Station (NCRPIS) were also evaluated. We measured RPR in three environments. Family-nested QTL were identified by joint-linkage mapping in the NAM panel. We also performed a genome-wide association study (GWAS) and genomic best linear unbiased prediction (GBLUP) in each panel. Broad sense heritability computed on a line means basis was low for RPR. Only 8 of 26 families had a heritability above 0.20. The NCRPIS diversity panel had a heritability of 0.54. Across NAM and IBM families, 18 family-nested QTL and 141 significant GWAS associations were identified for RPR. Numerous weak associations were also found in the NCRPIS diversity panel. However, few were linked to loci involved in phenylpropanoid and cellulose synthesis or vegetative phase transition. Using an identity-by-state (IBS) relationship matrix estimated from 1.6 million single nucleotide polymorphisms (SNPs) and RPR measures from 20% of the NAM panel, genomic prediction by GBLUP explained 64±2% of variation in the remaining RILs. In the NCRPIS diversity panel, an IBS matrix estimated from 681,257 SNPs and RPR measures from 20% of the panel explained 33±3% of variation in the remaining inbreds. These results indicate the high genetic complexity of stalk strength and the potential for genomic prediction to hasten its improvement. PMID:23840585

  6. Genetic, Physical, Maps, and Database Resources for Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resources for maize genetics and genomics exist in great depth and breadth. They can be brought to bear on its productivity, on selected properties, and on studies of genetic functions, mechanisms of inheritance, phylogeny, and processes of change during domestication. Genetic materials available ...

  7. The genetic architecture of maize height

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state (IBS) among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formida...

  8. Genetic Analysis of Rough Sheath1 Developmental Mutants of Maize

    PubMed Central

    Becraft, P. W.; Freeling, M.

    1994-01-01

    Maize Rough sheath1 (Rs1) mutants are dominant and cause a proliferation of sheath-like tissue at the base of the blade and throughout the ligular region. They also cause ligule displacement, a chaotic pattern of vasculature and abnormal cellular structure of vascular bundles. The affected region of Rs1-O leaves displays genetic and morphological attributes of both sheath and auricle, suggesting an overlap of these genetic programs. The rs1 locus maps approximately 26 map units distal to opaque2 (o2) on chromosome 7S, defining a new distal-most locus on the genetic map. Three mutant alleles, Rs1-O, Rs1-1025 and Rs1-Z, all display similar phenotypes. The mutations are completely dominant and the Rs1-O phenotype is not affected by dosage of the chromosome arm carrying the rs1(+) allele, indicating that these alleles are neomorphic. Analysis of genetic mosaics showed that the Rs1-O phenotype is non-cell-autonomous, suggesting that intercellular signals convey the phenotype. Rs1 mutant phenotypes are affected by modifiers present in particular genetic backgrounds. An enhancer of Rs1-O was identified; segregation data imply a single recessive gene, ers1. Rs1 mutants were also found to enhance the expression of unlinked rs2 and Rs4 mutants, suggesting that these mutations affect similar developmental processes. We discuss the phenotypic and genetic similarities between Rs1 and Knotted1 (Kn1) mutants that led to the identification of rs1 as a kn1-like homeobox gene (unpublished data). PMID:8138166

  9. From many, one: genetic control of prolificacy during maize domestication.

    PubMed

    Wills, David M; Whipple, Clinton J; Takuno, Shohei; Kursel, Lisa E; Shannon, Laura M; Ross-Ibarra, Jeffrey; Doebley, John F

    2013-06-01

    A reduction in number and an increase in size of inflorescences is a common aspect of plant domestication. When maize was domesticated from teosinte, the number and arrangement of ears changed dramatically. Teosinte has long lateral branches that bear multiple small ears at their nodes and tassels at their tips. Maize has much shorter lateral branches that are tipped by a single large ear with no additional ears at the branch nodes. To investigate the genetic basis of this difference in prolificacy (the number of ears on a plant), we performed a genome-wide QTL scan. A large effect QTL for prolificacy (prol1.1) was detected on the short arm of chromosome 1 in a location that has previously been shown to influence multiple domestication traits. We fine-mapped prol1.1 to a 2.7 kb "causative region" upstream of the grassy tillers1 (gt1) gene, which encodes a homeodomain leucine zipper transcription factor. Tissue in situ hybridizations reveal that the maize allele of prol1.1 is associated with up-regulation of gt1 expression in the nodal plexus. Given that maize does not initiate secondary ear buds, the expression of gt1 in the nodal plexus in maize may suppress their initiation. Population genetic analyses indicate positive selection on the maize allele of prol1.1, causing a partial sweep that fixed the maize allele throughout most of domesticated maize. This work shows how a subtle cis-regulatory change in tissue specific gene expression altered plant architecture in a way that improved the harvestability of maize. PMID:23825971

  10. [Detection of genetic modification in maize and maize products by ELISA-test].

    PubMed

    Urbanek-Karłowska, Bogumiła; Sawilska-Rautenstrauch, Dorota; Jedra, Małgorzata; Badowski, Paweł

    2003-01-01

    Enzyme immunoassay methods--TRAIT Test--was applied for detection of genetic modification in maize seeds and foodstuffs, which have been produced from this crop. TRAIT Test is based on the identification GMO protein Cry 1Ab produced by a gene derived from Bacillus thuringiensis (Bt) incorporated into insect resistant corn grain. The experiment was carried out on maize standards and foodstuffs from Warsaw market. The positive result was obtained for one maize product, which was not labelled as GMO. The presence of GMO material was approximately equal to 1%. In conclusion, this test is proper for fast routine qualitative (yes/no) determination GMO material in maize seeds and unprocessed food products. PMID:15052732

  11. Molecular Genetics of Mitochondrial Biogenesis in Maize.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mitochondrial genome encodes proteins essential for mitochondrial respiration and ATP synthesis. Nuclear gene products, however, are required for the expression of mitochondrial genes and the elaboration of functional mitochondrial protein complexes. We are exploiting a unique collection of maiz...

  12. Genetic Modifiers for Neuromuscular Diseases

    PubMed Central

    Lamar, Kay-Marie; McNally, Elizabeth M.

    2015-01-01

    Neuromuscular diseases, which encompass disorders that affect muscle and its innervation, are highly heritable. Genetic diagnosis now frequently pinpoints the primary mutation responsible for a given neuromuscular disease. However, the results from genetic testing indicate that neuromuscular disease phenotypes may vary widely, even in individuals with the same primary disease-causing mutation. Clinical variability arises from both genetic and environmental factors. Genetic modifiers can now be identified using candidate gene as well as genomic approaches. The presence of genetic modifiers for neuromuscular disease helps define the clinical outcome and also highlights pathways of potential therapeutic utility. Herein, we will focus on single gene neuromuscular disorders, including muscular dystrophy, spinal muscular atrophy, and amyotrophic lateral sclerosis, and the methods that have been used to identify modifier genes. Animal models have been an invaluable resource for modifier gene discovery and subsequent mechanistic studies. Some modifiers, identified using animal models, have successfully translated to the human counterpart. Furthermore, in a few instances, modifier gene discovery has repetitively uncovered the same pathway, such as TGFβ signaling in muscular dystrophy, further emphasizing the relevance of that pathway. Knowledge of genetic factors that influence disease can have direct clinical applications for prognosis and predicted outcome. PMID:25729645

  13. Genetic Characterization of a Core Set of a Tropical Maize Race Tuxpeño for Further Use in Maize Improvement

    PubMed Central

    Chavez-Tovar, Victor H.; Yan, Jianbing; Taba, Suketoshi

    2012-01-01

    The tropical maize race Tuxpeño is a well-known race of Mexican dent germplasm which has greatly contributed to the development of tropical and subtropical maize gene pools. In order to investigate how it could be exploited in future maize improvement, a panel of maize germplasm accessions was assembled and characterized using genome-wide Single Nucleotide Polymorphism (SNP) markers. This panel included 321 core accessions of Tuxpeño race from the International Maize and Wheat Improvement Center (CIMMYT) germplasm bank collection, 94 CIMMYT maize lines (CMLs) and 54 U.S. Germplasm Enhancement of Maize (GEM) lines. The panel also included other diverse sources of reference germplasm: 14 U.S. maize landrace accessions, 4 temperate inbred lines from the U.S. and China, and 11 CIMMYT populations (a total of 498 entries with 795 plants). Clustering analyses (CA) based on Modified Rogers Distance (MRD) clearly partitioned all 498 entries into their corresponding groups. No sub clusters were observed within the Tuxpeño core set. Various breeding strategies for using the Tuxpeño core set, based on grouping of the studied germplasm and genetic distance among them, were discussed. In order to facilitate sampling diversity within the Tuxpeño core, a minicore subset of 64 Tuxpeño accessions (20% of its usual size) representing the diversity of the core set was developed, using an approach combining phenotypic and molecular data. Untapped diversity represents further use of the Tuxpeño landrace for maize improvement through the core and/or minicore subset available to the maize community. PMID:22412898

  14. THE MAIZE MAPPING PROJECT: COMPREHENSIVE GENETIC, PHYSICAL AND DATABASE RESOURCES FOR MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Progress in preparing an integrated genetic and physical map of maize is described. The strategy is to fingerprint bacterial artificial chromosome (BAC) fragments and assemble the fragments in a deep-coverage resource, accompanied by pegging with markers to confirm and to intercalate the assembled c...

  15. Prospects for reducing fumonisin contamination of maize through genetic modification.

    PubMed Central

    Duvick, J

    2001-01-01

    Fumonisins (FB) are mycotoxins found in (italic)Fusarium verticillioides-infected maize grain worldwide. Attention has focused on FBs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. FBs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. Among the strategies for reducing risk of FB contamination in maize supplied to the market, development and deployment of Fusarium ear mold-resistant maize germplasm is a high priority. Breeding for increased ear mold tolerance and reduced mycotoxin levels is being practiced today in both commercial and public programs, but the amount of resistance achievable may be limited due to complicated genetics and/or linkage to undesirable agronomic traits. Molecular markers can be employed to speed up the incorporation of chromosomal regions that have a quantitative effect on resistance (quantitative trait loci). Transgenic approaches to ear mold/mycotoxin resistance are now feasible as well. These potentially include genetically enhanced resistance to insect feeding, increased fungal resistance, and detoxification/prevention of mycotoxins in the grain. An example of the first of these approaches is already on the market, namely transgenic maize expressing Bacillus thuringiensis (Bt) toxin, targeted to the European corn borer. Some Bt maize hybrids have the potential to reduce FB levels in field-harvested grain, presumably through reduced feeding of Bt-susceptible insects in ear tissues. However, improved ear mold resistance per se is still an important goal, as the plant will still be vulnerable to noninsect routes of entry to (italic)Fusarium. A second approach, transgene-mediated control of the ability of Fusarium to infect and colonize the ear, could potentially be achieved through overexpression of specific antifungal proteins and metabolites, or enhancement of the plant's own defense systems in kernel tissues. This has not yet been accomplished in maize, although promising results have been obtained recently in other monocots versus other fungal and bacterial pathogens. Achieving reproducible and stable enhanced ear mold resistance under field conditions will be immensely challenging for biotechnologists. A third approach, transgene strategies aimed at preventing mycotoxin biosynthesis, or detoxifying mycotoxins in planta, could provide further protection for the grower in environments where FBs present a risk to the crop even when the maize is relatively resistant to Fusarium mold. In one example of such a strategy, enzymes that degrade FBs have been identified in a filamentous saprophytic fungus isolated from maize, and corresponding genes have been cloned and are currently being tested in transgenic maize. PMID:11359705

  16. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Octenylsuccinic anhydride (OSA)-modified starches with degree of substitution of 0.018 (OS-S-L) and 0.092 (OS-S-H) were prepared from granular native waxy maize starch in an aqueous slurry system. The substitution distribution of OS groups was investigated by enzyme hydrolysis followed by chromatogr...

  17. Genetic adjustment to changing climates: MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prospects for more widespread and frequent drought in the near future are placing considerable pressure on maize breeding programs to develop more drought tolerant germplasm. Despite the complexity of the plant’s responses to water limited conditions, rational application of molecular/genomic ap...

  18. The genetic architecture of maize stalk strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stalk strength is an important trait in maize (Zea mays L.). Strong stalks reduce lodging and maximize harvestable yield. Studies show rind penetrometer resistance (RPR), or the force required to pierce a stalk rind with a spike, is a valid approximation of strength. We measured RPR across 4,892 rec...

  19. Maize Genetics Outreach to American Indians

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is an excellent vehicle for plant genomics outreach to those American Indian tribes who use and appreciate it nutritionally, culturally, and spiritually. During the summer 2006 season we mentored six Native American Indian students for eight weeks. All six worked at the USDA-ARS North Centra...

  20. The Genetic Basis of Disease Resistance in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The advent of high throughput genomics has accelerated progress in understanding the genetic basis of disease resistance in maize, much as it enhanced discovery in other fields. Here we summarize progress made in recent years using resources such as association mapping and nested association mapping...

  1. Molecular genetic basis of pod corn (Tunicate maize)

    PubMed Central

    Wingen, Luzie U.; Münster, Thomas; Faigl, Wolfram; Deleu, Wim; Sommer, Hans; Saedler, Heinz; Theißen, Günter

    2012-01-01

    Pod corn is a classic morphological mutant of maize in which the mature kernels of the cob are covered by glumes, in contrast to generally grown maize varieties in which kernels are naked. Pod corn, known since pre-Columbian times, is the result of a dominant gain-of-function mutation at the Tunicate (Tu) locus. Some classic articles of 20th century maize genetics reported that the mutant Tu locus is complex, but molecular details remained elusive. Here, we show that pod corn is caused by a cis-regulatory mutation and duplication of the ZMM19 MADS-box gene. Although the WT locus contains a single-copy gene that is expressed in vegetative organs only, mutation and duplication of ZMM19 in Tu lead to ectopic expression of the gene in the inflorescences, thus conferring vegetative traits to reproductive organs. PMID:22517751

  2. Metabolomics of Genetically Modified Crops

    PubMed Central

    Simó, Carolina; Ibáñez, Clara; Valdés, Alberto; Cifuentes, Alejandro; García-Cañas, Virginia

    2014-01-01

    Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. PMID:25334064

  3. Metabolomics of genetically modified crops.

    PubMed

    Simó, Carolina; Ibáñez, Clara; Valdés, Alberto; Cifuentes, Alejandro; García-Cañas, Virginia

    2014-01-01

    Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. PMID:25334064

  4. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding

    PubMed Central

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-01-01

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects. PMID:26308050

  5. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding.

    PubMed

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-08-01

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects. PMID:26308050

  6. DNA extraction methods for detecting genetically modified foods: A comparative study.

    PubMed

    Elsanhoty, Rafaat M; Ramadan, Mohamed Fawzy; Jany, Klaus Dieter

    2011-06-15

    The work presented in this manuscript was achieved to compare six different methods for extracting DNA from raw maize and its derived products. The methods that gave higher yield and quality of DNA were chosen to detect the genetic modification in the samples collected from the Egyptian market. The different methods used were evaluated for extracting DNA from maize kernels (without treatment), maize flour (mechanical treatment), canned maize (sweet corn), frozen maize (sweet corn), maize starch, extruded maize, popcorn, corn flacks, maize snacks, and bread made from corn flour (mechanical and thermal treatments). The quality and quantity of the DNA extracted from the standards, containing known percentages of GMO material and from the different food products were evaluated. For qualitative detection of the GMO varieties in foods, the GMOScreen 35S/NOS test kit was used, to screen the genetic modification in the samples. The positive samples for the 35S promoter and/or the NOS terminator were identified by the standard methods adopted by EU. All of the used methods extracted yielded good DNA quality. However, we noted that the purest DNA extract were obtained using the DNA extraction kit (Roche) and this generally was the best method for extracting DNA from most of the maize-derived foods. We have noted that the yield of DNA extracted from maize-derived foods was generally lower in the processed products. The results indicated that 17 samples were positive for the presence of 35S promoter, while 34% from the samples were positive for the genetically modified maize line Bt-176. PMID:25213972

  7. The Physical and Genetic Framework of the B73 Maize Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn (Maize) is a major cereal crop and an important model system for basic biological research. Knowledge gained from maize research can also be used to genetically improve its grass relatives such as sorghum, wheat, rice. The primary objective of the Maize Genome Sequencing Consortium (MGSC) was t...

  8. Genetic Perturbation of the Maize Methylome[W

    PubMed Central

    Li, Qing; Hermanson, Peter J.; Zaunbrecher, Virginia M.; Song, Jawon; Wendt, Jennifer; Rosenbaum, Heidi; Madzima, Thelma F.; Sloan, Amy E.; Huang, Ji; Burgess, Daniel L.; Richmond, Todd A.; McGinnis, Karen M.; Meeley, Robert B.; Danilevskaya, Olga N.; Vaughn, Matthew W.; Kaeppler, Shawn M.; Jeddeloh, Jeffrey A.

    2014-01-01

    DNA methylation can play important roles in the regulation of transposable elements and genes. A collection of mutant alleles for 11 maize (Zea mays) genes predicted to play roles in controlling DNA methylation were isolated through forward- or reverse-genetic approaches. Low-coverage whole-genome bisulfite sequencing and high-coverage sequence-capture bisulfite sequencing were applied to mutant lines to determine context- and locus-specific effects of these mutations on DNA methylation profiles. Plants containing mutant alleles for components of the RNA-directed DNA methylation pathway exhibit loss of CHH methylation at many loci as well as CG and CHG methylation at a small number of loci. Plants containing loss-of-function alleles for chromomethylase (CMT) genes exhibit strong genome-wide reductions in CHG methylation and some locus-specific loss of CHH methylation. In an attempt to identify stocks with stronger reductions in DNA methylation levels than provided by single gene mutations, we performed crosses to create double mutants for the maize CMT3 orthologs, Zmet2 and Zmet5, and for the maize DDM1 orthologs, Chr101 and Chr106. While loss-of-function alleles are viable as single gene mutants, the double mutants were not recovered, suggesting that severe perturbations of the maize methylome may have stronger deleterious phenotypic effects than in Arabidopsis thaliana. PMID:25527708

  9. Genetically modified organisms and monitoring.

    PubMed

    Diamand, E

    1999-12-01

    The genetic modification of organisms for food use has raised serious concern about the potential for adverse effects on the environment, ecosystems and on the health of humans and animals. As a relatively new technology, its impacts remain uncertain but could range from disturbances to the genetic functioning of individual organisms to a reduction in the biodiversity of farmland. As a result, the question of how to monitor for potential impacts is beset with problems. The fact that genetic modification can be used on a range of organisms for a variety of purposes means that those developing monitoring systems will need to be as imaginative as those developing GMOs. In the case of genetically modified organisms (GMOs) for food use, concern has focussed on the transfer of genes to other organisms, the potential for effects on non-target organisms, or on the health of humans and animals, and the likelihood of adverse effects on wildlife due to changes in farming practice. As with other new and unfamiliar technologies, genetic modification is also plagued by the problem of uncertainty. Novel genes are inserted randomly into the genome of the host organisms, and this leads to the possibility of unexpected effects. Unanticipated environmental disasters, such as the concentration of persistent organic pollutants in ecosystems at high latitudes, have highlighted the need for monitoring despite the obvious difficulties inherent in monitoring for unexpected effects. PMID:11529177

  10. Genetic analysis of arsenic accumulation in maize using QTL mapping

    PubMed Central

    Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

    2016-01-01

    Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars. PMID:26880701

  11. Genetic analysis of arsenic accumulation in maize using QTL mapping.

    PubMed

    Fu, Zhongjun; Li, Weihua; Xing, Xiaolong; Xu, Mengmeng; Liu, Xiaoyang; Li, Haochuan; Xue, Yadong; Liu, Zonghua; Tang, Jihua

    2016-01-01

    Arsenic (As) is a toxic heavy metal that can accumulate in crops and poses a threat to human health. The genetic mechanism of As accumulation is unclear. Herein, we used quantitative trait locus (QTL) mapping to unravel the genetic basis of As accumulation in a maize recombinant inbred line population derived from the Chinese crossbred variety Yuyu22. The kernels had the lowest As content among the different maize tissues, followed by the axes, stems, bracts and leaves. Fourteen QTLs were identified at each location. Some of these QTLs were identified in different environments and were also detected by joint analysis. Compared with the B73 RefGen v2 reference genome, the distributions and effects of some QTLs were closely linked to those of QTLs detected in a previous study; the QTLs were likely in strong linkage disequilibrium. Our findings could be used to help maintain maize production to satisfy the demand for edible corn and to decrease the As content in As-contaminated soil through the selection and breeding of As pollution-safe cultivars. PMID:26880701

  12. The genetic architecture of leaf number and its genetic relationship to flowering time in maize.

    PubMed

    Li, Dan; Wang, Xufeng; Zhang, Xiangbo; Chen, Qiuyue; Xu, Guanghui; Xu, Dingyi; Wang, Chenglong; Liang, Yameng; Wu, Lishuan; Huang, Cheng; Tian, Jinge; Wu, Yaoyao; Tian, Feng

    2016-04-01

    The number of leaves and their distributions on plants are critical factors determining plant architecture in maize (Zea mays), and leaf number is frequently used as a measure of flowering time, a trait that is key to local environmental adaptation. Here, using a large set of 866 maize-teosinte BC2 S3 recombinant inbred lines genotyped by using 19 838 single nucleotide polymorphism markers, we conducted a comprehensive genetic dissection to assess the genetic architecture of leaf number and its genetic relationship to flowering time. We demonstrated that the two components of total leaf number, the number of leaves above (LA) and below (LB) the primary ear, were under relatively independent genetic control and might be subject to differential directional selection during maize domestication and improvement. Furthermore, we revealed that flowering time and leaf number are commonly regulated at a moderate level. The pleiotropy of the genes ZCN8, dlf1 and ZmCCT on leaf number and flowering time were validated by near-isogenic line analysis. Through fine mapping, qLA1-1, a major-effect locus that specifically affects LA, was delimited to a region with severe recombination suppression derived from teosinte. This study provides important insights into the genetic basis of traits affecting plant architecture and adaptation. The genetic independence of LA from LB enables the optimization of leaf number for ideal plant architecture breeding in maize. PMID:26593156

  13. Genetically modified bacteria in agriculture.

    PubMed

    Amarger, N

    2002-11-01

    Certain bacteria isolated from soils possess properties that allow them to exert beneficial effects on plants either by enhancing crop nutrition or by reducing damages caused by pathogens or pests. Some of them, such as rhizobia, azospirilla, and agrobacteria, have been traditionally released in fields as seed inoculants and they often lead to increases in the yield of different crops while the application of others, such as pseudomonads, often fails to give the expected results. Bacteria genetically modified to be easily traceable and/or to be improved in their expression of beneficial traits have been constructed and released with plants in a number of experimental field plots. With these releases, it has been possible to monitor the modified inoculant bacteria after their introduction in field ecosystems and to assess their impact on the resident microflora. Local environmental factors appeared as playing a crucial role in the survival and persistence of bacteria once released in fields and in the expression of the beneficial traits whether improved or not. The spread of inoculant bacteria from their point of dissemination was limited. Transient shifts in favour of the released bacteria and in disfavour of some members of the bacterial and fungal populations present in the plant rhizosphere might occur with certain released bacteria. The changes observed were, however, less important than those observed under usual agricultural practices. Gene transfer from resident population to introduced bacteria was detected in one case. The transconjugants were found only transiently in the phytosphere of plants but not in soils. No differences between the survival, spread, persistence in field and ecological impacts of genetically modified bacteria and of the corresponding unmodified parent strain could be detected. PMID:12595134

  14. The population genetics of maize dwarf mosaic virus in Spain.

    PubMed

    Achon, M A; Larrañaga, A; Alonso-Dueñas, N

    2012-12-01

    The population genetics of maize dwarf mosaic virus (MDMV) in Spain was assessed by analysis of the P1-HC region. Restriction fragment length polymorphism analysis of 363 isolates revealed that the MDMV population consisted of 69 haplotypes. Sequence analysis of 112 isolates confirmed a high degree of nucleotide sequence diversity (0.143), which was higher for P1 than for the HC. Twelve sequences showed a single different recombination event. Selection pressure analysis revealed that the P1-HC region was under strong negative selection. The MDMV population was spatially structured but not structured temporally or by host. Phylogenetic analysis split the sequences into five major groups. PMID:22855126

  15. Identification of Genetic Differentiation between Waxy and Common Maize by SNP Genotyping

    PubMed Central

    Hao, Derong; Zhang, Zhenliang; Cheng, Yujing; Chen, Guoqing; Lu, Huhua; Mao, Yuxiang; Shi, Mingliang; Huang, Xiaolan; Zhou, Guangfei; Xue, Lin

    2015-01-01

    Waxy maize (Zea mays L. var. ceratina) is an important vegetable and economic crop that is thought to have originated from cultivated flint maize and most recently underwent divergence from common maize. In this study, a total of 110 waxy and 110 common maize inbred lines were genotyped with 3072 SNPs to evaluate the genetic diversity, population structure, and linkage disequilibrium decay as well as identify putative loci that are under positive selection. The results revealed abundant genetic diversity in the studied panel and that genetic diversity was much higher in common than in waxy maize germplasms. Principal coordinate analysis and neighbor-joining cluster analysis consistently classified the 220 accessions into two major groups and a mixed group with mixed ancestry. Subpopulation structure in both waxy and common maize sets were associated with the germplasm origin and corresponding heterotic groups. The LD decay distance (1500–2000 kb) in waxy maize was lower than that in common maize. Fourteen candidate loci were identified as under positive selection between waxy and common maize at the 99% confidence level. The information from this study can assist waxy maize breeders by enhancing parental line selection and breeding program design. PMID:26566240

  16. Analysis of genetic traits for drought tolerance in maize.

    PubMed

    Muhammad, R W; Qayyum, A; Hamza, A; Ahmad, M Q; Naseer, N S; Liaqat, S; Ahmad, B; Malik, W; Noor, E

    2015-01-01

    Fifty-four genotypes of maize were crossed and evaluated in the field during the crop season in February 2012 under both normal and water stress conditions. To identify the major parameters responsible for variation among genotypes, single linkage cluster analysis and principle component analysis (PCA) were carried out. Thirteen characters were studied. The PCA showed that the first six components, with eigen values >1, contributed 82.30% of the variability among the genotypes under normal field irrigation conditions while other PCs (7-13) had eigen values less than 1. Under drought conditions, the first four PCs, with eigen values >1, contributed 64.79% of the variability among genotypes while the other PCs (5-13) had eigen values less than 1. In the absence of water stress, heritability ranged from 68% (sucrose content) to 99% (plant height) and genetic advance ranged between 158.43% for stomatal frequency and 0.87 for biological yield. Under drought conditions, the coefficient of variability (CV) was 1.43-7.79, whereas estimates of heritability ranged between 68% and 99% for sucrose content and leaf area, respectively. The values of genetic advance ranged between 153.41 for stomatal frequency and 0.47 for nitrogen content. CV was 1.52-7.38 under drought conditions. The results indicated that the plant characters studied were under the control of additive genetic effects and suggested that selection should lead to fast genetic improvements. Clusters with superior agronomic types were identified and could be exploited for the transfer of desirable genes to improve the yield potential of the maize crop. PMID:26535668

  17. Overexpression of ARGOS Genes Modifies Plant Sensitivity to Ethylene, Leading to Improved Drought Tolerance in Both Arabidopsis and Maize.

    PubMed

    Shi, Jinrui; Habben, Jeffrey E; Archibald, Rayeann L; Drummond, Bruce J; Chamberlin, Mark A; Williams, Robert W; Lafitte, H Renee; Weers, Ben P

    2015-09-01

    Lack of sufficient water is a major limiting factor to crop production worldwide, and the development of drought-tolerant germplasm is needed to improve crop productivity. The phytohormone ethylene modulates plant growth and development as well as plant response to abiotic stress. Recent research has shown that modifying ethylene biosynthesis and signaling can enhance plant drought tolerance. Here, we report novel negative regulators of ethylene signal transduction in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). These regulators are encoded by the ARGOS gene family. In Arabidopsis, overexpression of maize ARGOS1 (ZmARGOS1), ZmARGOS8, Arabidopsis ARGOS homolog ORGAN SIZE RELATED1 (AtOSR1), and AtOSR2 reduced plant sensitivity to ethylene, leading to enhanced drought tolerance. RNA profiling and genetic analysis suggested that the ZmARGOS1 transgene acts between an ethylene receptor and CONSTITUTIVE TRIPLE RESPONSE1 in the ethylene signaling pathway, affecting ethylene perception or the early stages of ethylene signaling. Overexpressed ZmARGOS1 is localized to the endoplasmic reticulum and Golgi membrane, where the ethylene receptors and the ethylene signaling protein ETHYLENE-INSENSITIVE2 and REVERSION-TO-ETHYLENE SENSITIVITY1 reside. In transgenic maize plants, overexpression of ARGOS genes also reduces ethylene sensitivity. Moreover, field testing showed that UBIQUITIN1:ZmARGOS8 maize events had a greater grain yield than nontransgenic controls under both drought stress and well-watered conditions. PMID:26220950

  18. Analysis of genetically modified organisms by pyrosequencing on a portable photodiode-based bioluminescence sequencer.

    PubMed

    Song, Qinxin; Wei, Guijiang; Zhou, Guohua

    2014-07-01

    A portable bioluminescence analyser for detecting the DNA sequence of genetically modified organisms (GMOs) was developed by using a photodiode (PD) array. Pyrosequencing on eight genes (zSSIIb, Bt11 and Bt176 gene of genetically modified maize; Lectin, 35S-CTP4, CP4EPSPS, CaMV35S promoter and NOS terminator of the genetically modified Roundup ready soya) was successfully detected with this instrument. The corresponding limit of detection (LOD) was 0.01% with 35 PCR cycles. The maize and soya available from three different provenances in China were detected. The results indicate that pyrosequencing using the small size of the detector is a simple, inexpensive, and reliable way in a farm/field test of GMO analysis. PMID:24518318

  19. Detection of Genetically Modified Food: Has Your Food Been Genetically Modified?

    ERIC Educational Resources Information Center

    Brandner, Diana L.

    2002-01-01

    Explains the benefits and risks of genetically-modified foods and describes methods for genetically modifying food. Presents a laboratory experiment using a polymerase chain reaction (PCR) test to detect foreign DNA in genetically-modified food. (Contains 18 references.) (YDS)

  20. Traceability of genetically modified organisms.

    PubMed

    Aarts, Henk J M; van Rie, Jean-Paul P F; Kok, Esther J

    2002-01-01

    EU regulations stipulate the labeling of food products containing genetically modified organisms (GMOs) unless the GMO content is due to adventitious and unintended 'contamination' and not exceeding the 1% level at ingredient basis. In addition, member states have to ensure full traceability at all stages of the placing on the market of GMOs. Both requirements ensure consumers 'right to know', facilitate enforcement of regulatory requirements and are of importance for environmental monitoring and postmarket surveillance. Besides administrative procedures, such as used in quality certification systems, the significance of adequate molecular methods becomes more and more apparent. During the last decade a considerable number of molecular methods have been developed and validated that enable the detection, identification and quantification of GMO impurities. Most of them rely on the PCR technology and can only detect one specific stretch of DNA. It can, however, be anticipated that in the near future the situation will become more complex. The number of GMO varieties, including 'stacked-gene' varieties, which will enter the European Market will increase and it is likely that these varieties will harbor more variable constructs. New tools will be necessary to keep up with these developments. One of the most promising techniques is microarray analysis. This technique enables the screening for a large number of different GMOs within a single experiment. PMID:11963810

  1. Influence of genetic background on anthocyanin and copigment composition and behavior during thermoalkaline processing of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visual color is a primary factor for foods purchase; identifying factors that influence in-situ color quality of pigmented maize during processing is important. We used 24 genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) to investigate the effect of pigment and copigme...

  2. Genetic, Genomic, and Breeding Approaches to Further Explore Kernel Composition Traits and Grain Yield in Maize

    ERIC Educational Resources Information Center

    Da Silva, Helena Sofia Pereira

    2009-01-01

    Maize ("Zea mays L.") is a model species well suited for the dissection of complex traits which are often of commercial value. The purpose of this research was to gain a deeper understanding of the genetic control of maize kernel composition traits starch, protein, and oil concentration, and also kernel weight and grain yield. Germplasm with

  3. Physical and Genetic Structure of the Maize Genome Reflects its Complex Evolutionary History

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) is one of the most important cereal crops and a model for the study of genetics, evolution, and domestication. To better understand maize genome organization and build a framework for genome sequencing, we constructed a sequence ready fingerprinted contig (FPC)-based physical ma...

  4. A BAC POOLING STRATEGY: POWERFUL TOOL FOR THE MAIZE INTEGRATED GENETIC AND PHYSICAL MAP CONSTRUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The construction of an integrated genetic and physical map of the maize genome (2500 Mbp) is the primary goal of our ongoing maize genome project. To accomplish this goal, we have used a BAC pooling strategy combined with a high-throughput PCR-based screening method to facilitate anchoring of the m...

  5. Genetic, Genomic, and Breeding Approaches to Further Explore Kernel Composition Traits and Grain Yield in Maize

    ERIC Educational Resources Information Center

    Da Silva, Helena Sofia Pereira

    2009-01-01

    Maize ("Zea mays L.") is a model species well suited for the dissection of complex traits which are often of commercial value. The purpose of this research was to gain a deeper understanding of the genetic control of maize kernel composition traits starch, protein, and oil concentration, and also kernel weight and grain yield. Germplasm with…

  6. Genetic diversity of Hungarian Maize dwarf mosaic virus isolates.

    PubMed

    Gell, Gyöngyvér; Balázs, Ervin; Petrik, Kathrin

    2010-04-01

    The genetic diversity of the coat-protein (CP) region and the untranslated C-terminal region (3'UTR) of Maize dwarf mosaic virus (MDMV) was analyzed to evaluate the variability between isolates (inter-isolate sequence diversity). The results of inter-isolate sequence diversity analysis showed that the diversity of the MDMV CP gene is fairly high (p-distance: up to 0.136). During sequence analysis, a 13 amino-acid residue insertion and an 8 amino-acid residue deletion were found within the N-terminal region of the CP gene. The phylogenetic analysis showed that-unlike other potyvirus species in this subgroup-the MDMV isolates could not be distinguished on the basis of their host plants or geographic origins. PMID:20033839

  7. Testing for Genetically Modified Foods Using PCR

    ERIC Educational Resources Information Center

    Taylor, Ann; Sajan, Samin

    2005-01-01

    The polymerase chain reaction (PCR) is a Nobel Prize-winning technique that amplifies a specific segment of DNA and is commonly used to test for the presence of genetic modifications. Students use PCR to test corn meal and corn-muffin mixes for the presence of a promoter commonly used in genetically modified foods, the cauliflower mosaic virus 35S

  8. Testing for Genetically Modified Foods Using PCR

    ERIC Educational Resources Information Center

    Taylor, Ann; Sajan, Samin

    2005-01-01

    The polymerase chain reaction (PCR) is a Nobel Prize-winning technique that amplifies a specific segment of DNA and is commonly used to test for the presence of genetic modifications. Students use PCR to test corn meal and corn-muffin mixes for the presence of a promoter commonly used in genetically modified foods, the cauliflower mosaic virus 35S…

  9. Maize Seed Chitinase is Modified by a Protein Secreted by Bipolaris zeicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants contain defense mechanisms that prevent infection by most fungi. Some specialized fungi have the ability to overcome plant defenses. The Zea mays (maize) seed chitinase ChitA has been previously reported as an antifungal protein. Here we report that ChitA is converted to a modified form by...

  10. Modification of recombinant maize ChitA chitinase by fungal chitinase-modifying proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In commercial maize, there are at least two different alleles of the chiA gene that encode alloforms of ChitA chitinase, a protein that is abundant in developing seed. Both known alloforms are modified by Bz-cmp, a protein secreted by the fungal pathogen Bipolaris zeicola. One alloform (ChitA-B73) i...

  11. Genetic structure and diversity among maize inbred lines as inferred from DNA microsatellites.

    PubMed Central

    Liu, Kejun; Goodman, Major; Muse, Spencer; Smith, J Stephen; Buckler, Ed; Doebley, John

    2003-01-01

    Two hundred and sixty maize inbred lines, representative of the genetic diversity among essentially all public lines of importance to temperate breeding and many important tropical and subtropical lines, were assayed for polymorphism at 94 microsatellite loci. The 2039 alleles identified served as raw data for estimating genetic structure and diversity. A model-based clustering analysis placed the inbred lines in five clusters that correspond to major breeding groups plus a set of lines showing evidence of mixed origins. A "phylogenetic" tree was constructed to further assess the genetic structure of maize inbreds, showing good agreement with the pedigree information and the cluster analysis. Tropical and subtropical inbreds possess a greater number of alleles and greater gene diversity than their temperate counterparts. The temperate Stiff Stalk lines are on average the most divergent from all other inbred groups. Comparison of diversity in equivalent samples of inbreds and open-pollinated landraces revealed that maize inbreds capture <80% of the alleles in the landraces, suggesting that landraces can provide additional genetic diversity for maize breeding. The contributions of four different segments of the landrace gene pool to each inbred group's gene pool were estimated using a novel likelihood-based model. The estimates are largely consistent with known histories of the inbreds and indicate that tropical highland germplasm is poorly represented in maize inbreds. Core sets of inbreds that capture maximal allelic richness were defined. These or similar core sets can be used for a variety of genetic applications in maize. PMID:14704191

  12. Advances in maize genomics and their value for enhancing genetic gains from breeding.

    PubMed

    Xu, Yunbi; Skinner, Debra J; Wu, Huixia; Palacios-Rojas, Natalia; Araus, Jose Luis; Yan, Jianbing; Gao, Shibin; Warburton, Marilyn L; Crouch, Jonathan H

    2009-01-01

    Maize is an important crop for food, feed, forage, and fuel across tropical and temperate areas of the world. Diversity studies at genetic, molecular, and functional levels have revealed that, tropical maize germplasm, landraces, and wild relatives harbor a significantly wider range of genetic variation. Among all types of markers, SNP markers are increasingly the marker-of-choice for all genomics applications in maize breeding. Genetic mapping has been developed through conventional linkage mapping and more recently through linkage disequilibrium-based association analyses. Maize genome sequencing, initially focused on gene-rich regions, now aims for the availability of complete genome sequence. Conventional insertion mutation-based cloning has been complemented recently by EST- and map-based cloning. Transgenics and nutritional genomics are rapidly advancing fields targeting important agronomic traits including pest resistance and grain quality. Substantial advances have been made in methodologies for genomics-assisted breeding, enhancing progress in yield as well as abiotic and biotic stress resistances. Various genomic databases and informatics tools have been developed, among which MaizeGDB is the most developed and widely used by the maize research community. In the future, more emphasis should be given to the development of tools and strategic germplasm resources for more effective molecular breeding of tropical maize products. PMID:19688107

  13. Advances in Maize Genomics and Their Value for Enhancing Genetic Gains from Breeding

    PubMed Central

    Xu, Yunbi; Skinner, Debra J.; Wu, Huixia; Palacios-Rojas, Natalia; Araus, Jose Luis; Yan, Jianbing; Gao, Shibin; Warburton, Marilyn L.; Crouch, Jonathan H.

    2009-01-01

    Maize is an important crop for food, feed, forage, and fuel across tropical and temperate areas of the world. Diversity studies at genetic, molecular, and functional levels have revealed that, tropical maize germplasm, landraces, and wild relatives harbor a significantly wider range of genetic variation. Among all types of markers, SNP markers are increasingly the marker-of-choice for all genomics applications in maize breeding. Genetic mapping has been developed through conventional linkage mapping and more recently through linkage disequilibrium-based association analyses. Maize genome sequencing, initially focused on gene-rich regions, now aims for the availability of complete genome sequence. Conventional insertion mutation-based cloning has been complemented recently by EST- and map-based cloning. Transgenics and nutritional genomics are rapidly advancing fields targeting important agronomic traits including pest resistance and grain quality. Substantial advances have been made in methodologies for genomics-assisted breeding, enhancing progress in yield as well as abiotic and biotic stress resistances. Various genomic databases and informatics tools have been developed, among which MaizeGDB is the most developed and widely used by the maize research community. In the future, more emphasis should be given to the development of tools and strategic germplasm resources for more effective molecular breeding of tropical maize products. PMID:19688107

  14. Genetic Variation at Bx 1 Controls DIMBOA Content in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The main hydroxamic acid in maize (Zea mays L.) is 2-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA). DIMBOA confers resistance to leaf-feeding by several corn borers. Most genes involved in the DIMBOA metabolic pathway are located on the short arm of chromosome 4, and QTLs involved in maize resis...

  15. Genetic, evoluntionary and plant breedinginsights from the domestication of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural history of maize began nine thousand years ago when Mexican farmers started to collect the seeds of the wild grass, teosinte. Invaluable as a food source, maize permeated Mexican culture and religion. Its domestication eventually led to its adoption as a model organism, aided in large pa...

  16. Genetic analysis of water-deficit response traits in maize.

    PubMed

    Ahmad, M; Saleem, M; Ahsan, M; Ahmad, A

    2016-01-01

    A set of sixty inbred lines of maize (Zea mays L.) were screened in the greenhouse at the seedling stage under both normal and water-deficit conditions. Six water deficit-tolerant inbred lines were selected based on root to shoot ratios. These selected lines were crossed in a diallel pattern. The parental, F1, and reciprocal cross plants were planted in a field under both normal and water-deficit conditions. Normal irrigation was applied to the control set, while the water-deficit set received 50% of normal irrigation levels. Analyses of variance of various morpho-physiological parameters identified significant differences among the selected lines under both conditions, indicating the presence of significant genetic variability. Variance components for general combining ability (GCA), specific combining ability (SCA), and reciprocal effects for all the parameters were estimated to determine the relative importance of additive and non-additive or dominance type of gene action. Variance components for GCA were larger than for SCA indicating the preponderance of additive types of gene action for all the traits under study. Hybrids developed from inbred lines W-10 and W-64SP proved to have the best grain yield under normal and water-deficit conditions. Under water-deficit conditions, the best performing cross was B-34 x W-10. Hence, these inbred lines and the hybrids might be of value in future breeding programs. PMID:27051012

  17. [Genetically modified food--unnecessary controversy?].

    PubMed

    Tchórz, Michał; Radoniewicz-Chagowska, Anna; Lewandowska-Stanek, Hanna; Szponar, Elzbieta; Szponar, Jarosław

    2012-01-01

    Fast development of genetic engineering and biotechnology allows use of genetically modified organisms (GMO) more and more in different branches of science and economy. Every year we can see an increase of food amount produced with the use of modification of genetic material. In our supermarkets we can find brand new types of plants, products including genetically modified ingredients or meat from animals fed with food containing GMO. This article presents general information about genetically modified organisms, it also explains the range of genetic manipulation, use of newly developed products and current field area for GMO in the world. Based on scientific data the article presents benefits from development of biotechnology in reference to modified food. It also presents the voice of skeptics who are extremely concerned about the impact of those organisms on human health and natural environment. Problems that appear or can appear as a result of an increase of GMO are very important not only from a toxicologist's or a doctor's point of view but first of all from the point of view of ordinary consumers--all of us. PMID:23243917

  18. Genetically Modified Foods and Consumer Perspective.

    PubMed

    Boccia, Flavio; Sarnacchiaro, Pasquale

    2015-01-01

    Genetically modified food is able to oppose the world's hunger and preserve the environment, even if the patents in this matter are symptomatic of several doubts. And also, transgenic consumption causes problems and skepticism among consumers in several European countries, but above all in Italy, where there is a strong opposition over recent years. So, the present study conducted a research to study the consumption of genetically modified food products by Italian young generation. This research presented the following purposes: firstly, to analyze genetically modified products' consumption among a particular category of consumers; secondly, to implement a quantitative model to understand behaviour about this particular kind of consumption and identify the factors that determine their purchase. The proposed model shows that transgenic consumption is especially linked to knowledge and impact on environment and mankind's health. PMID:25827570

  19. Genetically modified animals and pharmacological research.

    PubMed

    Wells, Dominic J

    2010-01-01

    This chapter reviews the use of genetically modified animals and the increasingly detailed knowledge of the genomes of the domestic species. The different approaches to genetic modification are outlined as are the advantages and disadvantages of the techniques in different species. Genetically modified mice have been fundamental in understanding gene function and in generating affordable models of human disease although these are not without their drawbacks. Transgenic farm animals have been developed for nutritionally enhanced food, disease resistance and xenografting. Transgenic rabbits, goats, sheep and cows have been developed as living bioreactors producing potentially high value biopharmaceuticals, commonly referred to as "pharming". Domestic animals are also important as a target as well as for testing genetic-based therapies for both inherited and acquired disease. This latter field may be the most important of all, in the future development of novel therapies. PMID:20204589

  20. Genetically modified pig models for neurodegenerative disorders.

    PubMed

    Holm, Ida E; Alstrup, Aage Kristian Olsen; Luo, Yonglun

    2016-01-01

    Increasing incidence of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease has become one of the most challenging health issues in ageing humans. One approach to combat this is to generate genetically modified animal models of neurodegenerative disorders for studying pathogenesis, prognosis, diagnosis, treatment, and prevention. Owing to the genetic, anatomic, physiologic, pathologic, and neurologic similarities between pigs and humans, genetically modified pig models of neurodegenerative disorders have been attractive large animal models to bridge the gap of preclinical investigations between rodents and humans. In this review, we provide a neuroanatomical overview in pigs and summarize and discuss the generation of genetically modified pig models of neurodegenerative disorders including Alzheimer's diseases, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, spinal muscular atrophy, and ataxia-telangiectasia. We also highlight how non-invasive bioimaging technologies such as positron emission tomography (PET), computer tomography (CT), and magnetic resonance imaging (MRI), and behavioural testing have been applied to characterize neurodegenerative pig models. We further propose a multiplex genome editing and preterm recloning (MAP) approach by using the rapid growth of the ground-breaking precision genome editing technology CRISPR/Cas9 and somatic cell nuclear transfer (SCNT). With this approach, we hope to shorten the temporal requirement in generating multiple transgenic pigs, increase the survival rate of founder pigs, and generate genetically modified pigs that will more closely resemble the disease-causing mutations and recapitulate pathological features of human conditions. PMID:26446984

  1. [Effect of genetically modified plants on the development of rat progeny].

    PubMed

    Tyshko, N V; Zhminchenko, V M; Pashorina, V A; Saprykin, V P; Seliaskin, K E; Utembaeva, N T; Tutel'ian, V A

    2011-01-01

    The paper presents the results of evaluating the effect of genetically modified (GM) maize on the prenatal and postnatal development of rat progeny in three generations. An experiment used 280 adult rats (160 females and 120 males) and 1545 infant rats of the first month of life. The animals were divided into 2 groups: 1) those given a diet including GM maize (an experimental group); 2) those fed on its isogenic control (a control group). The maize was included into the diet in maximally possible amount that did not impair the balance of essential nutrients (31.4% caloric value). Analysis of the data obtained from studies of the prenatal (preimplantation and postimplantation death and fetal somatometric parameters) and postnatal (physical development, survival, changes in somatometric parameters) development of rat offspring revealed no effect of GM maize as compared to the isogenic control. All the parameters were in the normal physiological range typical of the animals of this species and age. Thus, dietary intake of the given amount of GM maize had no impact on rat progeny development. PMID:22250399

  2. Genetically Modified Plants: Public and Scientific Perceptions

    PubMed Central

    2013-01-01

    The potential of genetically modified plants to meet the requirements of growing population is not being recognized at present. This is a consequence of concerns raised by the public and the critics about their applications and release into the environment. These include effect on human health and environment, biosafety, world trade monopolies, trustworthiness of public institutions, integrity of regulatory agencies, loss of individual choice, and ethics as well as skepticism about the real potential of the genetically modified plants, and so on. Such concerns are enormous and prevalent even today. However, it should be acknowledged that most of them are not specific for genetically modified plants, and the public should not forget that the conventionally bred plants consumed by them are also associated with similar risks where no information about the gene(s) transfer is available. Moreover, most of the concerns are hypothetical and lack scientific background. Though a few concerns are still to be disproved, it is viewed that, with proper management, these genetically modified plants have immense potential for the betterment of mankind. In the present paper, an overview of the raised concerns and wherever possible reasons assigned to explain their intensity or unsuitability are reviewed. PMID:25937981

  3. Genetic modifiers of tauopathy in Drosophila.

    PubMed Central

    Shulman, Joshua M; Feany, Mel B

    2003-01-01

    In Alzheimer's disease and related disorders, the microtubule-associated protein Tau is abnormally hyperphosphorylated and aggregated into neurofibrillary tangles. Mutations in the tau gene cause familial frontotemporal dementia. To investigate the molecular mechanisms responsible for Tau-induced neurodegeneration, we conducted a genetic modifier screen in a Drosophila model of tauopathy. Kinases and phosphatases comprised the major class of modifiers recovered, and several candidate Tau kinases were similarly shown to enhance Tau toxicity in vivo. Despite some clinical and pathological similarities among neurodegenerative disorders, a direct comparison of modifiers between different Drosophila disease models revealed that the genetic pathways controlling Tau and polyglutamine toxicity are largely distinct. Our results demonstrate that kinases and phosphatases control Tau-induced neurodegeneration and have important implications for the development of therapies in Alzheimer's disease and related disorders. PMID:14668378

  4. Detection of genetically modified organisms in foods.

    PubMed

    Ahmed, Farid E

    2002-05-01

    Legislation enacted worldwide to regulate the presence of genetically modified organisms (GMOs) in crops, foods and ingredients, necessitated the development of reliable and sensitive methods for GMO detection. In this article, protein- and DNA-based methods employing western blots, enzyme-linked immunosorbant assay, lateral flow strips, Southern blots, qualitative-, quantitative-, real-time- and limiting dilution-PCR methods, are discussed. Where information on modified gene sequences is not available, new approaches, such as near-infrared spectrometry, might tackle the problem of detection of non-approved genetically modified (GM) foods. The efficiency of screening, identification and confirmation strategies should be examined with respect to false-positive rates, disappearance of marker genes, increased use of specific regulator sequences and the increasing number of GM foods. PMID:11943377

  5. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas

    PubMed Central

    Ortiz, Carlos S.; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-01-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  6. Computational identification of genetic subnetwork modules associated with maize defense response to Fusarium verticillioides

    PubMed Central

    2015-01-01

    Background Maize, a crop of global significance, is vulnerable to a variety of biotic stresses resulting in economic losses. Fusarium verticillioides (teleomorph Gibberella moniliformis) is one of the key fungal pathogens of maize, causing ear rots and stalk rots. To better understand the genetic mechanisms involved in maize defense as well as F. verticillioides virulence, a systematic investigation of the host-pathogen interaction is needed. The aim of this study was to computationally identify potential maize subnetwork modules associated with its defense response against F. verticillioides. Results We obtained time-course RNA-seq data from B73 maize inoculated with wild type F. verticillioides and a loss-of-virulence mutant, and subsequently established a computational pipeline for network-based comparative analysis. Specifically, we first analyzed the RNA-seq data by a cointegration-correlation-expression approach, where maize genes were jointly analyzed with known F. verticillioides virulence genes to find candidate maize genes likely associated with the defense mechanism. We predicted maize co-expression networks around the selected maize candidate genes based on partial correlation, and subsequently searched for subnetwork modules that were differentially activated when inoculated with two different fungal strains. Based on our analysis pipeline, we identified four potential maize defense subnetwork modules. Two were directly associated with maize defense response and were associated with significant GO terms such as GO:0009817 (defense response to fungus) and GO:0009620 (response to fungus). The other two predicted modules were indirectly involved in the defense response, where the most significant GO terms associated with these modules were GO:0046914 (transition metal ion binding) and GO:0046686 (response to cadmium ion). Conclusion Through our RNA-seq data analysis, we have shown that a network-based approach can enhance our understanding of the complicated host-pathogen interactions between maize and F. verticillioides by interpreting the transcriptome data in a system-oriented manner. We expect that the proposed analytic pipeline can also be adapted for investigating potential functional modules associated with host defense response in diverse plant-pathogen interactions. PMID:26423221

  7. Clarification of colloidal and suspended material in water using triethanolamine modified maize tassels.

    PubMed

    Kinyua, Esther Mbuci; Mwangi, Isaac W; Wanjau, Ruth N; Ngila, J C

    2016-03-01

    Suspended particles in water are a major concern in global pollution management. They affect the appreciation of water due to clarity, photosynthesis, and poor oxygen environment rendering water unsuitable for aquatic animals. Some suspended materials contain functional groups capable of forming complex compounds with metals making them available for poisoning. Such material promotes the growth of bacteria and fouling that give rise to unpleasant taste and odor of the water and thus requires removal. Removal of suspended solids is normally achieved through sedimentation or filtration. However, some suspended colloidal particles are very stable in water and cannot settle while others are able to pass through the filter due to small size, hence difficult to remove. This study investigated the use of triethanolamine-modified maize tassels to form a flocculent for their removal. The modified maize tassels were characterized using Fourier transform infrared (FTIR), and it was found that the triethanolamine was anchored within the cellulose structure of the maize tassels. Clarification parameters such as settling time, reagent dosage, and pH were investigated. The best clarification was at a pH of 6.0 with clearance being less than in 30 min. The optimal flocculent dosage was found to be 3.5 ml of the material, showing that the material has a potential of enhancing clarity in polluted water. PMID:26561324

  8. Genetic analysis of visually scored orange kernel color in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing levels of provitamin A carotenoids in maize (Zea mays L.) grain through plant breeding, termed biofortification, is an economical and sustainable way to help humans suffering from vitamin A deficiency (VAD). Unfortunately, in parts of Africa where VAD is prevalent, there is frequently a c...

  9. Genetic and biochemical analysis of iron bioavailability in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is a major cereal crop widely consumed in developing countries, which have a high prevalence of iron (Fe) deficiency including anemia. The major cause of Fe deficiency in these countries is an inadequate intake of bioavailable Fe, of which poverty is a major contributing factor. Therefore, b...

  10. Genetic and biochemical analysis of iron bioavailability in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is a major cereal crop widely consumed in developing countries, which have a high prevalence of iron (Fe) deficiency including anemia. The major cause of Fe deficiency in these countries is inadequate intake of bioavailable Fe, of which poverty is a major contributing factor. Therefore, biofor...

  11. Genetics and Biochemistry of Insect Resistance in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insects are a major concern for maize production worldwide. Host plant resistance to insects involves a number of chemical and biochemical factors that limit but rarely eliminate insect damage. Most chemical and many biochemical factors involved in resistance to insects are synthesized independent...

  12. GMEnzy: A Genetically Modified Enzybiotic Database

    PubMed Central

    Lu, Hairong; Li, Guodong; Huang, Qingshan

    2014-01-01

    GMEs are genetically modified enzybiotics created through molecular engineering approaches to deal with the increasing problem of antibiotic resistance prevalence. We present a fully manually curated database, GMEnzy, which focuses on GMEs and their design strategies, production and purification methods, and biological activity data. GMEnzy collects and integrates all available GMEs and their related information into one web based database. Currently GMEnzy holds 186 GMEs from published literature. The GMEnzy interface is easy to use, and allows users to rapidly retrieve data according to desired search criteria. GMEnzy’s construction will increase the efficiency and convenience of improving these bioactive proteins for specific requirements, and will expand the arsenal available for researches to control drug-resistant pathogens. This database will prove valuable for researchers interested in genetically modified enzybiotics studies. GMEnzy is freely available on the Web at http://biotechlab.fudan.edu.cn/database/gmenzy/. PMID:25084271

  13. GMEnzy: a genetically modified enzybiotic database.

    PubMed

    Wu, Hongyu; Huang, Jinjiang; Lu, Hairong; Li, Guodong; Huang, Qingshan

    2014-01-01

    GMEs are genetically modified enzybiotics created through molecular engineering approaches to deal with the increasing problem of antibiotic resistance prevalence. We present a fully manually curated database, GMEnzy, which focuses on GMEs and their design strategies, production and purification methods, and biological activity data. GMEnzy collects and integrates all available GMEs and their related information into one web based database. Currently GMEnzy holds 186 GMEs from published literature. The GMEnzy interface is easy to use, and allows users to rapidly retrieve data according to desired search criteria. GMEnzy's construction will increase the efficiency and convenience of improving these bioactive proteins for specific requirements, and will expand the arsenal available for researches to control drug-resistant pathogens. This database will prove valuable for researchers interested in genetically modified enzybiotics studies. GMEnzy is freely available on the Web at http://biotechlab.fudan.edu.cn/database/gmenzy/. PMID:25084271

  14. Earthworms modify microbial community structure and accelerate maize stover decomposition during vermicomposting.

    PubMed

    Chen, Yuxiang; Zhang, Yufen; Zhang, Quanguo; Xu, Lixin; Li, Ran; Luo, Xiaopei; Zhang, Xin; Tong, Jin

    2015-11-01

    In the present study, maize stover was vermicomposted with the epigeic earthworm Eisenia fetida. The results showed that, during vermicomposting process, the earthworms promoted decomposition of maize stover. Analysis of microbial communities of the vermicompost by high-throughput pyrosequencing showed more complex bacterial community structure in the substrate treated by the earthworms than that in the control group. The dominant microbial genera in the treatment with the earthworms were Pseudoxanthomonas, Pseudomonas, Arthrobacter, Streptomyces, Cryptococcus, Guehomyces, and Mucor. Compared to the control group, the relative abundance of lignocellulose degradation microorganisms increased. The results indicated that the earthworms modified the structure of microbial communities during vermicomposting process, activated the growth of lignocellulose degradation microorganisms, and triggered the lignocellulose decomposition. PMID:26139410

  15. Genetically modified foods and social concerns.

    PubMed

    Maghari, Behrokh Mohajer; Ardekani, Ali M

    2011-07-01

    Biotechnology is providing us with a wide range of options for how we can use agricultural and commercial forestry lands. The cultivation of genetically modified (GM) crops on millions of hectares of lands and their injection into our food chain is a huge global genetic experiment involving all living beings. Considering the fast pace of new advances in production of genetically modified crops, consumers, farmers and policymakers worldwide are challenged to reach a consensus on a clear vision for the future of world food supply. The current food biotechnology debate illustrates the serious conflict between two groups: 1) Agri-biotech investors and their affiliated scientists who consider agricultural biotechnology as a solution to food shortage, the scarcity of environmental resources and weeds and pests infestations; and 2) independent scientists, environmentalists, farmers and consumers who warn that genetically modified food introduces new risks to food security, the environment and human health such as loss of biodiversity; the emergence of superweeds and superpests; the increase of antibiotic resistance, food allergies and other unintended effects. This article reviews major viewpoints which are currently debated in the food biotechnology sector in the world. It also lays the ground-work for deep debate on benefits and risks of Biotech-crops for human health, ecosystems and biodiversity. In this context, although some regulations exist, there is a need for continuous vigilance for all countries involved in producing genetically engineered food to follow the international scientific bio-safety testing guidelines containing reliable pre-release experiments and post-release track of transgenic plants to protect public health and avoid future environmental harm. PMID:23408723

  16. Genetically Modified Foods and Social Concerns

    PubMed Central

    Maghari, Behrokh Mohajer; Ardekani, Ali M.

    2011-01-01

    Biotechnology is providing us with a wide range of options for how we can use agricultural and commercial forestry lands. The cultivation of genetically modified (GM) crops on millions of hectares of lands and their injection into our food chain is a huge global genetic experiment involving all living beings. Considering the fast pace of new advances in production of genetically modified crops, consumers, farmers and policymakers worldwide are challenged to reach a consensus on a clear vision for the future of world food supply. The current food biotechnology debate illustrates the serious conflict between two groups: 1) Agri-biotech investors and their affiliated scientists who consider agricultural biotechnology as a solution to food shortage, the scarcity of environmental resources and weeds and pests infestations; and 2) independent scientists, environmentalists, farmers and consumers who warn that genetically modified food introduces new risks to food security, the environment and human health such as loss of biodiversity; the emergence of superweeds and superpests; the increase of antibiotic resistance, food allergies and other unintended effects. This article reviews major viewpoints which are currently debated in the food biotechnology sector in the world. It also lays the ground-work for deep debate on benefits and risks of Biotech-crops for human health, ecosystems and biodiversity. In this context, although some regulations exist, there is a need for continuous vigilance for all countries involved in producing genetically engineered food to follow the international scientific bio-safety testing guidelines containing reliable pre-release experiments and post-release track of transgenic plants to protect public health and avoid future environmental harm. PMID:23408723

  17. SINGLE NUCLEOTIDE POLYMORPHISMS AND INDELS FOR THE DEVELOPMENT OF INTEGRATED PHYSICAL AND GENETIC MAPS OF MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single nucleotide polymorphisms (SNPs) and insertion-deletion polymorphisms (InDels) are becoming important genetic markers for major crop species. We amplified genomic regions corresponding to 678 unigenes across 12 maize inbred lines. The amplification products from 592 unigenes were sequenced (17...

  18. Genetic mapping shows intraspecific variation and transgressive segregation for caterpillar-induced aphid resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants in nature have inducible defenses that sometimes lead to targeted resistance against particular herbivores, but susceptibility to others. The metabolic diversity and genetic resources available for maize (Zea mays) make this a suitable system for a mechanistic study of within- species variati...

  19. Distinct genetic architectures for male and female inflorescence traits of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We compared the genetic architecture of thirteen maize morphological traits in a large population of recombinant inbred lines. Four traits from the male inflorescence (tassel) and three traits from the female inflorescence (ear) were measured and studied using linkage and genome-wide association ana...

  20. Maize databases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

  1. Overexpression of ARGOS Genes Modifies Plant Sensitivity to Ethylene, Leading to Improved Drought Tolerance in Both Arabidopsis and Maize[OPEN

    PubMed Central

    Shi, Jinrui; Habben, Jeffrey E.; Archibald, Rayeann L.; Drummond, Bruce J.; Chamberlin, Mark A.; Williams, Robert W.; Lafitte, H. Renee; Weers, Ben P.

    2015-01-01

    Lack of sufficient water is a major limiting factor to crop production worldwide, and the development of drought-tolerant germplasm is needed to improve crop productivity. The phytohormone ethylene modulates plant growth and development as well as plant response to abiotic stress. Recent research has shown that modifying ethylene biosynthesis and signaling can enhance plant drought tolerance. Here, we report novel negative regulators of ethylene signal transduction in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). These regulators are encoded by the ARGOS gene family. In Arabidopsis, overexpression of maize ARGOS1 (ZmARGOS1), ZmARGOS8, Arabidopsis ARGOS homolog ORGAN SIZE RELATED1 (AtOSR1), and AtOSR2 reduced plant sensitivity to ethylene, leading to enhanced drought tolerance. RNA profiling and genetic analysis suggested that the ZmARGOS1 transgene acts between an ethylene receptor and CONSTITUTIVE TRIPLE RESPONSE1 in the ethylene signaling pathway, affecting ethylene perception or the early stages of ethylene signaling. Overexpressed ZmARGOS1 is localized to the endoplasmic reticulum and Golgi membrane, where the ethylene receptors and the ethylene signaling protein ETHYLENE-INSENSITIVE2 and REVERSION-TO-ETHYLENE SENSITIVITY1 reside. In transgenic maize plants, overexpression of ARGOS genes also reduces ethylene sensitivity. Moreover, field testing showed that UBIQUITIN1:ZmARGOS8 maize events had a greater grain yield than nontransgenic controls under both drought stress and well-watered conditions. PMID:26220950

  2. Genetic mapping shows intraspecific variation and transgressive segregation for caterpillar-induced aphid resistance in maize.

    PubMed

    Tzin, Vered; Lindsay, Penelope L; Christensen, Shawn A; Meihls, Lisa N; Blue, Levi B; Jander, Georg

    2015-11-01

    Plants in nature have inducible defences that sometimes lead to targeted resistance against particular herbivores, but susceptibility to others. The metabolic diversity and genetic resources available for maize (Zea mays) make this a suitable system for a mechanistic study of within-species variation in such plant-mediated interactions between herbivores. Beet armyworms (Spodoptera exigua) and corn leaf aphids (Rhopalosiphum maidis) are two naturally occurring maize herbivores with different feeding habits. Whereas chewing herbivore-induced methylation of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc) to form 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) promotes caterpillar resistance, lower DIMBOA-Glc levels favour aphid reproduction. Thus, caterpillar-induced DIMBOA-Glc methyltransferase activity in maize is predicted to promote aphid growth. To test this hypothesis, the impact of S. exigua feeding on R. maidis progeny production was assessed using seventeen genetically diverse maize inbred lines. Whereas aphid progeny production was increased by prior caterpillar feeding on lines B73, Ki11, Ki3 and Tx303, it decreased on lines Ky21, CML103, Mo18W and W22. Genetic mapping of this trait in a population of B73 × Ky21 recombinant inbred lines identified significant quantitative trait loci on maize chromosomes 1, 7 and 10. There is a transgressive segregation for aphid resistance, with the Ky21 alleles on chromosomes 1 and 7 and the B73 allele on chromosome 10 increasing aphid progeny production. The chromosome 1 QTL coincides with a cluster of three maize genes encoding benzoxazinoid O-methyltransferases that convert DIMBOA-Glc to HDMBOA-Glc. Gene expression studies and benzoxazinoid measurements indicate that S. exigua -induced responses in this pathway differentially affect R. maidis resistance in B73 and Ky21. PMID:26462033

  3. Genetic analysis of resistance to six virus diseases in a multiple virus-resistant maize inbred line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus diseases in maize can cause severe yield reductions that threaten crop production and food supplies in some regions of the world. Genetic resistance to different viruses has been characterized in maize populations under diverse environments and screening techniques, and resistance loci have be...

  4. An ultra-high-density map as a community resource for discerning the genetic basis of quantitative traits in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we generated a linkage map containing 1,151,856 high quality SNPs between Mo17 and B73, which were verified in the maize intermated B73'×'Mo17 (IBM) Syn10 population. This resource is an excellent complement to existing maize genetic maps available in an online database (iPlant, http:...

  5. Engineering a thermoregulated intein-modified xylanase into maize for consolidated lignocellulosic biomass processing.

    PubMed

    Shen, Binzhang; Sun, Xueguang; Zuo, Xiao; Shilling, Taran; Apgar, James; Ross, Mary; Bougri, Oleg; Samoylov, Vladimir; Parker, Matthew; Hancock, Elaina; Lucero, Hector; Gray, Benjamin; Ekborg, Nathan A; Zhang, Dongcheng; Johnson, Jeremy C Schley; Lazar, Gabor; Raab, R Michael

    2012-11-01

    Plant cellulosic biomass is an abundant, low-cost feedstock for producing biofuels and chemicals. Expressing cell wall-degrading (CWD) enzymes (e.g. xylanases) in plant feedstocks could reduce the amount of enzymes required for feedstock pretreatment and hydrolysis during bioprocessing to release soluble sugars. However, in planta expression of xylanases can reduce biomass yield and plant fertility. To overcome this problem, we engineered a thermostable xylanase (XynB) with a thermostable self-splicing bacterial intein to control the xylanase activity. Intein-modified XynB (iXynB) variants were selected that have <10% wild-type enzymatic activity but recover >60% enzymatic activity upon intein self-splicing at temperatures >59 °C. Greenhouse-grown xynB maize expressing XynB has shriveled seeds and low fertility, but ixynB maize had normal seeds and fertility. Processing dried ixynB maize stover by temperature-regulated xylanase activation and hydrolysis in a cocktail of commercial CWD enzymes produced >90% theoretical glucose and >63% theoretical xylose yields. PMID:23086202

  6. Simultaneous Detection of Genetically Modified Organisms in a Mixture by Multiplex PCR-Chip Capillary Electrophoresis.

    PubMed

    Patwardhan, Supriya; Dasari, Srikanth; Bhagavatula, Krishna; Mueller, Steffen; Deepak, Saligrama Adavigowda; Ghosh, Sudip; Basak, Sanjay

    2015-01-01

    An efficient PCR-based method to trace genetically modified food and feed products is in demand due to regulatory requirements and contaminant issues in India. However, post-PCR detection with conventional methods has limited sensitivity in amplicon separation that is crucial in multiplexing. The study aimed to develop a sensitive post-PCR detection method by using PCR-chip capillary electrophoresis (PCR-CCE) to detect and identify specific genetically modified organisms in their genomic DNA mixture by targeting event-specific nucleotide sequences. Using the PCR-CCE approach, novel multiplex methods were developed to detect MON531 cotton, EH 92-527-1 potato, Bt176 maize, GT73 canola, or GA21 maize simultaneously when their genomic DNAs in mixtures were amplified using their primer mixture. The repeatability RSD (RSDr) of the peak migration time was 0.06 and 3.88% for the MON531 and Bt176, respectively. The RSD (RSDR) of the Cry1Ac peak ranged from 0.12 to 0.40% in multiplex methods. The method was sensitive in resolving amplicon of size difference up to 4 bp. The PCR-CCE method is suitable to detect multiple genetically modified events in a composite DNA sample by tagging their event specific sequences. PMID:26525256

  7. Genetically Modified (GM) Foods and Ethical Eating.

    PubMed

    Dizon, Francis; Costa, Sarah; Rock, Cheryl; Harris, Amanda; Husk, Cierra; Mei, Jenny

    2016-02-01

    The ability to manipulate and customize the genetic code of living organisms has brought forth the production of genetically modified organisms (GMOs) and consumption of genetically modified (GM) foods. The potential for GM foods to improve the efficiency of food production, increase customer satisfaction, and provide potential health benefits has contributed to the rapid incorporation of GM foods into the American diet. However, GM foods and GMOs are also a topic of ethical debate. The use of GM foods and GM technology is surrounded by ethical concerns and situational judgment, and should ideally adhere to the ethical standards placed upon food and nutrition professionals, such as: beneficence, nonmaleficence, justice and autonomy. The future of GM foods involves many aspects and trends, including enhanced nutritional value in foods, strict labeling laws, and potential beneficial economic conditions in developing nations. This paper briefly reviews the origin and background of GM foods, while delving thoroughly into 3 areas: (1) GMO labeling, (2) ethical concerns, and (3) health and industry applications. This paper also examines the relationship between the various applications of GM foods and their corresponding ethical issues. Ethical concerns were evaluated in the context of the code of ethics developed by the Academy of Nutrition and Dietetics (AND) that govern the work of food and nutrition professionals. Overall, there is a need to stay vigilant about the many ethical implications of producing and consuming GM foods and GMOs. PMID:26709962

  8. Genetic analysis of maturity and flowering characteristics in maize (Zea mays L.)

    PubMed Central

    Sher, Hassan; Iqbal, Muhammad; Khan, Kiramat; yasir, Muhammad; Hameed-ur-Rahman

    2012-01-01

    Objective To elucidate the pattern of inheritance and determine the relative magnitude of various genetic effects for maturity and flowering attributes in subtropical maize. Methods Four white grain maize inbred lines from flint group of corn, two with late maturity and two with early maturity, were used. These contrasting inbred lines were crossed to form four crosses. Six generations (P1, P2, F1, F2, BC1, and BC2) were developed for each individual cross. These were evaluated in triplicate trial for two consecutive years. Results Both dominance gene action and epistatic interaction played major role in governing inheritance of days to pollen shedding, 50% silking, anthesis silking interval and maturity. Conclusions Preponderance of dominance gene action for these traits indicated their usefulness in hybrid programs of subtropical maize. PMID:23569982

  9. Identification and genetic characterization of maize cell wall variation for improved biorefinery feedstock characteristics

    SciTech Connect

    Pauly, Markus; Hake, Sarah

    2013-10-31

    The objectives of this program are to 1) characterize novel maize mutants with altered cell walls for enhanced biorefinery characteristics and 2) find quantitative trait loci (QTLs) related to biorefinery characteristics by taking advantage of the genetic diversity of maize. As a result a novel non-transgenic maize plant (cal1) has been identified, whose stover (leaves and stalk) contain more glucan in their walls leading to a higher saccharification yield, when subjected to a standard enzymatic digestion cocktail. Stacking this trait with altered lignin mutants yielded evene higher saccharification yields. Cal-1 mutants do not show a loss of kernel and or biomass yield when grown in the field . Hence, cal1 biomass provides an excellent feedstock for the biofuel industry.

  10. Fatty acid production in genetically modified cyanobacteria

    PubMed Central

    Liu, Xinyao; Sheng, Jie; Curtiss III, Roy

    2011-01-01

    To avoid costly biomass recovery in photosynthetic microbial biofuel production, we genetically modified cyanobacteria to produce and secrete fatty acids. Starting with introducing an acyl–acyl carrier protein thioesterase gene, we made six successive generations of genetic modifications of cyanobacterium Synechocystis sp. PCC6803 wild type (SD100). The fatty acid secretion yield was increased to 197 ± 14 mg/L of culture in one improved strain at a cell density of 1.0 × 109 cells/mL by adding codon-optimized thioesterase genes and weakening polar cell wall layers. Although these strains exhibited damaged cell membranes at low cell densities, they grew more rapidly at high cell densities in late exponential and stationary phase and exhibited less cell damage than cells in wild-type cultures. Our results suggest that fatty acid secreting cyanobacteria are a promising technology for renewable biofuel production. PMID:21482809

  11. Spectroscopic characterization of genetically modified flax fibers

    NASA Astrophysics Data System (ADS)

    Dymińska, L.; Gągor, A.; Hanuza, J.; Kulma, A.; Preisner, M.; Żuk, M.; Szatkowski, M.; Szopa, J.

    2014-09-01

    The principal goal of this paper is an analysis of flax fiber composition. Natural and genetically modified flax fibers derived from transgenic flax have been analyzed. Development of genetic engineering enables to improve the quality of fibers. Three transgenic plant lines with different modifications were generated based on fibrous flax plants as the origin. These are plants with: silenced cinnamyl alcohol dehydrogenase (CAD) gene; overexpression of polygalacturonase (PGI); and expression of three genes construct containing β-ketothiolase (phb A), acetoacetyl-CoA reductase (phb B), and poly-3-hydroxybutyric acid synthase (phb C). Flax fibers have been studied by FT-IR spectroscopy. The integral intensities of the IR bands have been used for estimation of the chemical content of the normal and transgenic flaxes. The spectroscopic data were compared to those obtained from chemical analysis of flax fibers. X-ray studies have been used to characterize the changes of the crystalline structure of the flax cellulose fibers.

  12. [Genetically modified organisms (GMO): toxicological aspects].

    PubMed

    Ludwicki, J K

    1998-01-01

    The genetically modified organisms (GMO) are one of the major public concerns partially due to the activity of the non-governmental organizations which believe that public opinion must be duly informed on what leaves the laboratories and enters the environment or is proposed as food. This article discusses some major toxicological and nutritional aspects of GMO designed as food for humans. The range of current use of GMOs, potential hazards for humans, safety assessment, allergenic concerns, and some aspects of the use of marker genes are discussed in regard to human safety. The need for relevant regulations is stressed. PMID:9930018

  13. Reinventing MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

  14. A somatic gene rearrangement contributing to genetic diversity in maize

    SciTech Connect

    Das, O.P.; Levi-Minzi, S.; Koury, M.; Benner, M.; Messing, J. )

    1990-10-01

    The authors have discovered a somatic genomic rearrangement that occurs at high frequency at a duplicated zein locus in certain cultures of the maize inbred line A188. The rearranged allele arises from the duplication by a two-step process involving a homologous recombination and a second event, which may be a deletion, inversion, or insertion; both steps always occur together. The frequency of rearrangement is lower in homozygous states of the parental allele than in heterozygotes. In both cases, the rearrangement is shown to be mitotic. The rearranged product can be transmitted through meiosis, providing another mechanism for genome evolution in higher eukaryotes.

  15. Screening Maize Germplasm for Resistance to Western and Northern Corn Rootworms (Chrysomelidae: Diabrotica spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), with a subterranean larval stage that consumes root tissue. To lessen reliance on soil insecticides and provide alternatives for genetically modified maize hybrids, researchers have developed novel maize germpla...

  16. Societal aspects of genetically modified foods.

    PubMed

    Frewer, L; Lassen, J; Kettlitz, B; Scholderer, J; Beekman, V; Berdal, K G

    2004-07-01

    This paper aims to examine some of the reasons behind public controversy associated with the introduction of genetically modified foods in Europe the 1990s. The historical background to the controversy is provided to give context. The issue of public acceptance of genetically modified foods, and indeed the emerging biosciences more generally, is considered in the context of risk perceptions and attitudes, public trust in regulatory institutions, scientists, and industry, and the need to develop communication strategies that explicitly include public concerns rather than exclude them. Increased public participation has been promoted as a way of increasing trust in institutional practices associated with the biosciences, although questions still arise as to how to best utilise the outputs of such exercises in policy development. This issue will become more of a priority as decision-making systems become more transparent and open to public scrutiny. The results are discussed in the context of risk assessment and risk management, and recommendations for future research are made. In particular, it is recommended that new methods are developed in order to integrate public values more efficaciously into risk analysis processes, specifically with respect to the biosciences and to technology implementation in general. PMID:15123386

  17. Genetic control of abscisic acid biosynthesis in maize

    PubMed Central

    Tan, Bao Cai; Schwartz, Steven H.; Zeevaart, Jan A. D.; McCarty, Donald R.

    1997-01-01

    Abscisic acid (ABA), an apocarotenoid synthesized from cleavage of carotenoids, regulates seed maturation and stress responses in plants. The viviparous seed mutants of maize identify genes involved in synthesis and perception of ABA. Two alleles of a new mutant, viviparous14 (vp14), were identified by transposon mutagenesis. Mutant embryos had normal sensitivity to ABA, and detached leaves of mutant seedlings showed markedly higher rates of water loss than those of wild type. The ABA content of developing mutant embryos was 70% lower than that of wild type, indicating a defect in ABA biosynthesis. vp14 embryos were not deficient in epoxy-carotenoids, and extracts of vp14 embryos efficiently converted the carotenoid cleavage product, xanthoxin, to ABA, suggesting a lesion in the cleavage reaction. vp14 was cloned by transposon tagging. The VP14 protein sequence is similar to bacterial lignostilbene dioxygenases (LSD). LSD catalyzes a double-bond cleavage reaction that is closely analogous to the carotenoid cleavage reaction of ABA biosynthesis. Southern blots indicated a family of four to six related genes in maize. The Vp14 mRNA is expressed in embryos and roots and is strongly induced in leaves by water stress. A family of Vp14-related genes evidently controls the first committed step of ABA biosynthesis. These genes are likely to play a key role in the developmental and environmental control of ABA synthesis in plants. PMID:9342392

  18. Genetic diversity of maize kernel starch-synthesis genes with SNAPs.

    PubMed

    Shin, Ji-Hyun; Kwon, Soon-Jae; Lee, Ju Kyong; Min, Hwang-Kee; Kim, Nam-Soo

    2006-10-01

    Measuring genetic diversity in populations of a crop species is very important for understanding the genetic structure of and subsequently improving the crop species by genetic manipulation. Single-nucleotide amplified polymorphisms (SNAPs) among and within maize populations of waxy, dent, and sweet corns at 25 single-nucleotide polymorphism (SNP) sites in 6 kernel starch-synthesis genes (sh2, bt2, su1, ae1, wx1, and sh1) were determined. Because of the intensive selection of some favorable alleles in starch-synthesis genes during the breeding process, and the resultant strong linkage disequilibrium (LD), the number of haplotypes in each population was far less than expected. Subsequent phenetic clustering analysis with the SNAPs indicated that the dent, waxy, and sweet corns formed distinct subclusters, except in a few incidences. LD was surveyed among SNAPs of intragenic, intergenic, and intrachromosomal SNPs in whole and subpopulations, which revealed that some SNAPs showed high LD with many other SNAPs, but some SNAPs showed low or no significant LD with others, depending on the subpopulation, indicating that these starch genes have undergone different selection in each subpopulation during the breeding process. Because the starch synthesis genes used in this study are important in maize breeding, the genetic diversity, LD, and accessions having rare SNAP alleles might be valuable in maize improvement programs. PMID:17213911

  19. MATERNAL EFFECTS IN ADVANCED HYBRIDS OF GENETICALLY MODIFIED AND NON-GENETICALLY MODIFIED BRASSICA SPECIES

    EPA Science Inventory

    Identification of fitness traits potentially impacted by gene flow from genetically modified (GM) crops to compatible relatives is of interest in risk assessments for GM crops. Reciprocal crosses were made between GM canola, Brassica napus cv. RaideRR that expresses CP4 EPSPS fo...

  20. Genetic Analysis of 63 Mutations Affecting Maize Kernel Development Isolated from Mutator Stocks

    PubMed Central

    Scanlon, M. J.; Stinard, P. S.; James, M. G.; Myers, A. M.; Robertson, D. S.

    1994-01-01

    Sixty-three mutations affecting development of the maize kernel were isolated from active Robertson's Mutator (Mu) stocks. At least 14 previously undescribed maize gene loci were defined by mutations in this collection. Genetic mapping located 53 of these defective kernel (dek) mutations to particular chromosome arms, and more precise map determinations were made for 21 of the mutations. Genetic analyses identified 20 instances of allelism between one of the novel mutations and a previously described dek mutation, or between new dek mutations identified in this study; phenotypic variability was observed in three of the allelic series. Viability testing of homozygous mutant kernels identified numerous dek mutations with various pleiotropic effects on seedling and plant development. The mutations described here presumably arose by insertion of a Mu transposon within a dek gene; thus, many of the affected loci are expected to be accessible to molecular cloning via transposon-tagging. PMID:8138165

  1. Genetic Resources for Maize Cell Wall Biology1[C][W][OA

    PubMed Central

    Penning, Bryan W.; Hunter, Charles T.; Tayengwa, Reuben; Eveland, Andrea L.; Dugard, Christopher K.; Olek, Anna T.; Vermerris, Wilfred; Koch, Karen E.; McCarty, Donald R.; Davis, Mark F.; Thomas, Steven R.; McCann, Maureen C.; Carpita, Nicholas C.

    2009-01-01

    Grass species represent a major source of food, feed, and fiber crops and potential feedstocks for biofuel production. Most of the biomass is contributed by cell walls that are distinct in composition from all other flowering plants. Identifying cell wall-related genes and their functions underpins a fundamental understanding of growth and development in these species. Toward this goal, we are building a knowledge base of the maize (Zea mays) genes involved in cell wall biology, their expression profiles, and the phenotypic consequences of mutation. Over 750 maize genes were annotated and assembled into gene families predicted to function in cell wall biogenesis. Comparative genomics of maize, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) sequences reveal differences in gene family structure between grass species and a reference eudicot species. Analysis of transcript profile data for cell wall genes in developing maize ovaries revealed that expression within families differed by up to 100-fold. When transcriptional analyses of developing ovaries before pollination from Arabidopsis, rice, and maize were contrasted, distinct sets of cell wall genes were expressed in grasses. These differences in gene family structure and expression between Arabidopsis and the grasses underscore the requirement for a grass-specific genetic model for functional analyses. A UniformMu population proved to be an important resource in both forward- and reverse-genetics approaches to identify hundreds of mutants in cell wall genes. A forward screen of field-grown lines by near-infrared spectroscopic screen of mature leaves yielded several dozen lines with heritable spectroscopic phenotypes. Pyrolysis-molecular beam mass spectrometry confirmed that several nir mutants had altered carbohydrate-lignin compositions. PMID:19926802

  2. Indicators to assess temporal genetic diversity in the French Catalogue: no losses for maize and peas.

    PubMed

    Le Clerc, V; Cadot, V; Canadas, M; Lallemand, J; Guèrin, D; Boulineau, F

    2006-11-01

    The aim of this study, led by the GEVES (Research and Control Group for Varieties and Seeds), was to suggest indicators to assess the diversity available to farmers since the French Official Catalogue for Plant Varieties and Species was initiated. The largest datasets of 1990 inbred maize lines and 578 pea lines from the last 50 years were analysed using morphological and enzymatic parameters. Lines were grouped into three to five periods. Genetic diversity was estimated in each period from morphological and enzymatic markers by computing numerous indices, such as the number of classes of scores for each characteristic, allelic richness or genetic diversity index (H ( e )). Population differentiation parameters (G(ST), G(ST)', F(ST), Q(ST)) were also estimated between periods. While genetic diversity computed from distinction, uniformity, stability traits was more marked for maize (0.66) than for garden peas (0.35) or feed peas (0.29), the opposite trend was observed with enzymes, resulting in a genetic diversity of 0.43, 0.35 and 0.22 for garden peas, feed peas and maize, respectively. However, no significant changes in genetic diversity were observed over time, and genetic differentiation was slight between periods. All our results demonstrated that no significant reduction in the diversity available to farmers had been observed since initiation of the French Catalogue. The H ( e ) was a good indicator providing a quantitative estimate of genetic diversity, but it should be interpreted alongside a more precise indicator such as allelic richness or the number of classes for morphological characteristics. PMID:16900350

  3. Identification of functional genetic variations underlying drought tolerance in maize using SNP markers.

    PubMed

    Hao, Zhuanfang; Li, Xinhai; Xie, Chuanxiao; Weng, Jianfeng; Li, Mingshun; Zhang, Degui; Liang, Xiaoling; Liu, Lingling; Liu, Sisi; Zhang, Shihuang

    2011-08-01

    Single nucleotide polymorphism (SNP) is a common form of genetic variation and popularly exists in maize genome. An Illumina GoldenGate assay with 1 536 SNP markers was used to genotype maize inbred lines and identified the functional genetic variations underlying drought tolerance by association analysis. Across 80 lines, 1 006 polymorphic SNPs (65.5% of the total) in the assay with good call quality were used to estimate the pattern of genetic diversity, population structure, and familial relatedness. The analysis showed the best number of fixed subgroups was six, which was consistent with their original sources and results using only simple sequence repeat markers. Pairwise linkage disequilibrium (LD) and association mapping with phenotypic traits investigated under water-stressed and well-watered regimes showed rapid LD decline within 100-500 kb along the physical distance of each chromosome, and that 29 SNPs were associated with at least two phenotypic traits in one or more environments, which were related to drought-tolerant or drought-responsive genes. These drought-tolerant SNPs could be converted into functional markers and then used for maize improvement by marker-assisted selection. PMID:21564545

  4. Chinese newspaper coverage of genetically modified organisms

    PubMed Central

    2012-01-01

    Background Debates persist around the world over the development and use of genetically modified organisms (GMO). News media has been shown to both reflect and influence public perceptions of health and science related debates, as well as policy development. To better understand the news coverage of GMOs in China, we analyzed the content of articles in two Chinese newspapers that relate to the development and promotion of genetically modified technologies and GMOs. Methods Searching in the Chinese National Knowledge Infrastructure Core Newspaper Database (CNKI-CND), we collected 77 articles, including news reports, comments and notes, published between January 2002 and August 2011 in two of the major Chinese newspapers: People’s Daily and Guangming Daily. We examined articles for perspectives that were discussed and/or mentioned regarding GMOs, the risks and benefits of GMOs, and the tone of news articles. Results The newspaper articles reported on 29 different kinds of GMOs. Compared with the possible risks, the benefits of GMOs were much more frequently discussed in the articles. 48.1% of articles were largely supportive of the GM technology research and development programs and the adoption of GM cottons, while 51.9% of articles were neutral on the subject of GMOs. Risks associated with GMOs were mentioned in the newspaper articles, but none of the articles expressed negative tones in regards to GMOs. Conclusion This study demonstrates that the Chinese print media is largely supportive of GMOs. It also indicates that the print media describes the Chinese government as actively pursuing national GMO research and development programs and the promotion of GM cotton usage. So far, discussion of the risks associated with GMOs is minimal in the news reports. The media, scientists, and the government should work together to ensure that science communication is accurate and balanced. PMID:22551150

  5. Genetically modified plants for law enforcement applications

    NASA Astrophysics Data System (ADS)

    Stewart, C. Neal, Jr.

    2002-08-01

    Plants are ubiquitous in the environment and have the unique ability to respond to their environment physiologically and through altered gene expression profiles (they cannot walk away). In addition, plant genetic transformation techniques and genomic information in plants are becoming increasingly advanced. We have been performing research to express the jellyfish green fluorescent protein (GFP) in plants. GFP emits green light when excited by blue or UV light. In addition, my group and collaborators have developed methods to detect GFP in plants by contact instruments and at a standoff. There are several law enforcement applications for this technology. One involves using tagging and perhaps modifying drug plants genetically. In one instance, we could tag them for destruction. In another, we could adulterate them directly. Another application is one that falls into the chemical terrorism and bioterrorism countermeasures category. We are developing plants to sense toxins and whole organisms covertly. Plants are well adapted to monitor large geographic areas; biosurveillance. Some examples of research being performed focus on plants with plant pathogen inducible promoters fused to GFP for disease sensing, and algae biosensors for chemicals.

  6. Production of resistant starch by extrusion cooking of acid-modified normal-maize starch.

    PubMed

    Hasjim, Jovin; Jane, Jay-Lin

    2009-09-01

    The objective of this study was to utilize extrusion cooking and hydrothermal treatment to produce resistant starch (RS) as an economical alternative to a batch-cooking process. A hydrothermal treatment (110 degrees C, 3 d) of batch-cooked and extruded starch samples facilitated propagation of heat-stable starch crystallites and increased the RS contents from 2.1% to 7.7% up to 17.4% determined using AOAC Method 991.43 for total dietary fiber. When starch samples were batch cooked and hydrothermally treated at a moisture content below 70%, acid-modified normal-maize starch (AMMS) produced a greater RS content than did native normal-maize starch (NMS). This was attributed to the partially hydrolyzed, smaller molecules in the AMMS, which had greater mobility and freedom than the larger molecules in the NMS. The RS contents of the batch-cooked and extruded AMMS products after the hydrothermal treatment were similar. A freezing treatment of the AMMS samples at -20 degrees C prior to the hydrothermal treatment did not increase the RS content. The DSC thermograms and the X-ray diffractograms showed that retrograded amylose and crystalline starch-lipid complex, which had melting temperatures above 100 degrees C, accounted for the RS contents. PMID:19895460

  7. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology.

    PubMed

    Johnston, Robyn; Candela, Héctor; Hake, Sarah; Foster, Toshi

    2010-07-01

    Plant lateral organs, such as leaves, have three primary axes of growth-proximal-distal, medial--lateral and adaxial-abaxial (dorsal-ventral). Although most leaves are planar, modified leaf forms, such as the bikeeled grass prophyll, can be found in nature. A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive mutations in the maize (Zea mays) KANADI (KAN) gene milkweed pod1 (mwp1), which promotes abaxial cell identity, strongly affect development of the prophyll and silks (fused carpels). The prophyll is reduced to two unfused midribs and the silks are narrow and misshapen. Our data indicate that the prophyll and other fused organs are particularly sensitive to disruptions in adaxial-abaxial polarity. In addition, lateral and proximal-distal growth of most lateral organs is reduced in the mwp1-R mutant, supporting a role for the adaxial-abaxial boundary in promoting growth along both axes. We propose that the adaxial-abaxial patterning mechanism has been co-opted during evolution to generate diverse organ morphologies. PMID:20213690

  8. Removal of cadmium(II) from aqueous solutions by chemically modified maize straw.

    PubMed

    Guo, Hong; Zhang, Shufen; Kou, Zinong; Zhai, Shangru; Ma, Wei; Yang, Yi

    2015-01-22

    A new regenerable adsorbent was successfully prepared by modifying maize straw (MS) with succinic anhydride in xylene. The succinylated-maize straw (S-MS) was characterized by FTIR, solid-state MAS (13)C NMR spectroscopy, SEM-EDX and point of zero charge analysis. NaS-MS was successfully obtained after deprotonating the carboxylic acid groups of S-MS by Na2CO3 solution. Batch experiments were carried out with NaS-MS for the removal of Cd(II). The effects of pH, adsorbent dosage, contact time, initial concentration and temperature were investigated. The experimental data were best described by a pseudo-second-order kinetics and Langmuir adsorption models. Thermodynamic parameters (ΔG, ΔH, and ΔS) were also calculated from data obtained from experiments performed to study the effect of temperatures. NaS-MS could be regenerated at least five times in saturated NaCl solution without any loss. Furthermore, ∼97% of adsorbed Cd(II) ions could be recovered as the metal oxide. Finally, the adsorption mechanism of NaS-MS was discussed. PMID:25439883

  9. Genetic studies on cytoplasmic male sterility in maize

    SciTech Connect

    Laughnan, J.R.

    1992-01-01

    Our research concerns the basic mechanisms of cytoplasmic male sterility (CMS) and fertility restoration in maize. The molecular determination of CMS is in the DNA of the mitochondria (mtDNA) but specific nuclear restorer-of-fertility (Rf) genes can overrule the male-sterile effect of the cytoplasm. Our approach to the study of the Rf genes is threefold. We are attempting to tag the cms-S Rf genes and the cms-T Rf2 gene with controlling elements (CEs). Since we have identified a number of spontaneous Rf genes for cms-S and have demonstrated that they are themselves transposable, we are also searching for cases in which an Rf gene is inserted into a wild-type gene. The other aspect of our research involves the nuclear control over the organization of the mitochondrial genome. We found that the changes in mtDNA organization upon cytoplasmic reversion to fertility were characteristic of the nuclear background in which the reversion event occurred. We have investigated whether these differences are a reflection of differences in the organization of the mtDNA genome before reversion.

  10. Model studies on the detectability of genetically modified feeds in milk.

    PubMed

    Poms, R E; Hochsteiner, W; Luger, K; Glössl, J; Foissy, H

    2003-02-01

    Detecting the use of genetically modified feeds in milk has become important, because the voluntary labeling of milk and dairy products as "GMO free" or as "organically grown" prohibits the employment of genetically modified organisms (GMOs). The aim of this work was to investigate whether a DNA transfer from foodstuffs like soya and maize was analytically detectable in cow's milk after digestion and transportation via the bloodstream of dairy cows and, thus, whether milk could report for the employment of transgene feeds. Blood, milk, urine, and feces of dairy cows were examined, and foreign DNA was detected by polymerase chain reaction by specifically amplifying a 226-bp fragment of the maize invertase gene and a 118-bp fragment of the soya lectin gene. An intravenous application of purified plant DNA showed a fast elimination of marker DNA in blood or its reduction below the detection limit. With feeding experiments, it could be demonstrated that a specific DNA transfer from feeds into milk was not detectable. Therefore, foreign DNA in milk cannot serve as an indicator for the employment of transgene feeds unless milk is directly contaminated with feed components or airborne feed particles. PMID:12597493

  11. Weeds in fields with contrasting conventional and genetically modified herbicide-tolerant crops. II. Effects on individual species.

    PubMed Central

    Heard, M S; Hawes, C; Champion, G T; Clark, S J; Firbank, L G; Haughton, A J; Parish, A M; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Skellern, M P; Squire, G R; Hill, M O

    2003-01-01

    We compared the effects of the management of genetically modified herbicide-tolerant (GMHT) and conventional beet, maize and spring oilseed rape on 12 weed species. We sampled the seedbank before and after cropping. During the season we counted plants and measured seed rain and biomass. Ratios of densities were used to calculate emergence, survival, reproduction and seedbank change. Treatments significantly affected the biomass of six species in beet, eight in maize and five in spring oilseed rape. The effects were generally consistent, with biomass lower in GMHT beet and spring oilseed rape and higher in GMHT maize. With few exceptions, emergence was higher in GMHT crops. Subsequent survival was significantly lowered for eight species in beet and six in spring oilseed rape in the GMHT treatments. It was increased for five species in maize and one in spring oilseed rape. Significant effects on seedbank change were found for four species. However, for many species in beet and spring oilseed rape (19 out of 24 cases), seed densities were lower in the seedbank after GMHT cropping. These differences compounded over time would result in large decreases in population densities of arable weeds. In maize, populations may increase. PMID:14561317

  12. High-resolution genetic mapping of maize pan-genome sequence anchors.

    PubMed

    Lu, Fei; Romay, Maria C; Glaubitz, Jeffrey C; Bradbury, Peter J; Elshire, Robert J; Wang, Tianyu; Li, Yu; Li, Yongxiang; Semagn, Kassa; Zhang, Xuecai; Hernandez, Alvaro G; Mikel, Mark A; Soifer, Ilya; Barad, Omer; Buckler, Edward S

    2015-01-01

    In addition to single-nucleotide polymorphisms, structural variation is abundant in many plant genomes. The structural variation across a species can be represented by a 'pan-genome', which is essential to fully understand the genetic control of phenotypes. However, the pan-genome's complexity hinders its accurate assembly via sequence alignment. Here we demonstrate an approach to facilitate pan-genome construction in maize. By performing 18 trillion association tests we map 26 million tags generated by reduced representation sequencing of 14,129 maize inbred lines. Using machine-learning models we select 4.4 million accurately mapped tags as sequence anchors, 1.1 million of which are presence/absence variations. Structural variations exhibit enriched association with phenotypic traits, indicating that it is a significant source of adaptive variation in maize. The ability to efficiently map ultrahigh-density pan-genome sequence anchors enables fine characterization of structural variation and will advance both genetic research and breeding in many crops. PMID:25881062

  13. Genetic variation for maize root architecture in response to drought stress at the seedling stage

    PubMed Central

    Li, Rongyao; Zeng, Yijin; Xu, Jie; Wang, Qi; Wu, Fengkai; Cao, Moju; Lan, Hai; Liu, Yaxi; Lu, Yanli

    2015-01-01

    Although the root system is indispensable for absorption of nutrients and water, it is poorly studied in maize owing to the difficulties of direct measurement of roots. Here, 103 maize lines were used to compare root architectures under well-watered and water-stressed conditions. Significant genetic variation, with medium to high heritability and significant correlations, was observed for root traits. Total root length (TRL) and total root surface area (TSA) had high phenotypical diversity, and TRL was positively correlated with TSA, root volume, and root forks. The first two principal components explained 94.01% and 91.15% of total root variation in well-watered and water-stressed conditions, respectively. Thus, TRL and TSA, major contributors to root variation, can be used as favorable selection criteria at the seedling stage. We found that stiff stalk and non-stiff stalk groups (temperate backgrounds) showed relatively higher mean values for root morphological diversity than the TST group (tropical/subtropical background). Of the tested lines, 7, 42, 45, and 9 were classified as drought sensitive, moderately sensitive, moderately drought tolerant, and highly drought tolerant, respectively. Seven of the 9 extremely drought tolerant lines were from the TST group, suggesting that TST germplasms harbor valuable genetic resources for drought tolerance that could be used in breeding to improve abiotic stress tolerance in maize. PMID:26366112

  14. Genetic regulation and photocontrol of anthocyanin accumulation in maize seedlings.

    PubMed Central

    Taylor, L P; Briggs, W R

    1990-01-01

    The flavonoid pathway leading to anthocyanin biosynthesis in maize is controlled by multiple regulatory genes and induced by various developmental and environmental factors. We have investigated the effect of the regulatory loci R, B, and Pl on anthocyanin accumulation and on the expression of four genes (C2, A1, Bz1, and Bz2) in the biosynthetic pathway during an inductive light treatment. The results show that light-mediated anthocyanin biosynthesis is regulated solely by R; the contributions of B and Pl are negligible in young seedlings. Induction of the A1 and Bz2 genes by high fluence-rate white light requires the expression of a dominant R allele, whereas accumulation of C2 and Bz1 mRNA occurs with either a dominant or recessive allele at R. A1 and Bz2 mRNA accumulate only in response to high fluence-rate white light, but Bz1 is fully expressed in dim red light. Some C2 mRNA is induced by dim red light, but accumulation is far greater in high fluence-rate white light. Furthermore, expression from both dominant and recessive alleles of the regulatory gene R is enhanced by high fluence-rate white light. Seedlings with a recessive allele at R produce functional chalcone synthase protein (the C2 gene product) but accumulate no anthocyanins, suggesting that, in contrast to the R-mediated coordinate regulation of C2 and Bz1 observed in the aleurone, C2 expression in seedlings is independent of R and appears to be regulated by a different light-sensitive pathway. PMID:2136630

  15. Genetic regulation and photocontrol of anthocyanin accumulation in maize seedlings.

    PubMed

    Taylor, L P; Briggs, W R

    1990-02-01

    The flavonoid pathway leading to anthocyanin biosynthesis in maize is controlled by multiple regulatory genes and induced by various developmental and environmental factors. We have investigated the effect of the regulatory loci R, B, and Pl on anthocyanin accumulation and on the expression of four genes (C2, A1, Bz1, and Bz2) in the biosynthetic pathway during an inductive light treatment. The results show that light-mediated anthocyanin biosynthesis is regulated solely by R; the contributions of B and Pl are negligible in young seedlings. Induction of the A1 and Bz2 genes by high fluence-rate white light requires the expression of a dominant R allele, whereas accumulation of C2 and Bz1 mRNA occurs with either a dominant or recessive allele at R. A1 and Bz2 mRNA accumulate only in response to high fluence-rate white light, but Bz1 is fully expressed in dim red light. Some C2 mRNA is induced by dim red light, but accumulation is far greater in high fluence-rate white light. Furthermore, expression from both dominant and recessive alleles of the regulatory gene R is enhanced by high fluence-rate white light. Seedlings with a recessive allele at R produce functional chalcone synthase protein (the C2 gene product) but accumulate no anthocyanins, suggesting that, in contrast to the R-mediated coordinate regulation of C2 and Bz1 observed in the aleurone, C2 expression in seedlings is independent of R and appears to be regulated by a different light-sensitive pathway. PMID:2136630

  16. Genetic Modifiers of the p53 Pathway.

    PubMed

    Basu, Subhasree; Murphy, Maureen E

    2016-01-01

    The tumor suppressor geneTP53is the most frequently mutated gene in human cancer; this gene is subject to inactivation by mutation or deletion in >50% of sporadic cancers. Genes that encode proteins that regulate p53 function, such asMDM2,MDM4, andCDKN2A(p14(ARF)) are also frequently altered in tumors, and it is generally believed that the p53 pathway is likely to be inactivated by mutation in close to 100% of human tumors. Unlike most other cancer-relevant signaling pathways, some of the genes in the p53 pathway contain functionally significant single nucleotide polymorphisms (SNPs) that alter the amplitude of signaling by this protein. These variants, thus, have the potential to impact cancer risk, progression, and the efficacy of radiation and chemotherapy. In addition, the p53 pathway plays a role in other biological processes, including metabolism and reproductive fitness, so these variants have the potential to modify other diseases as well. Here we have chosen five polymorphisms in three genes in the p53 pathway for review, two inTP53, two inMDM2, and one inMDM4 These five variants were selected based on the quality and reproducibility of functional data associated with them, as well as the convincingness of epidemiological data in support of their association with disease. We also highlight two other polymorphisms that may affect p53 signaling, but for which functional or association data are still forthcoming (KITLGandANRIL). Finally, we touch on three questions regarding genetic modifiers of the p53 pathway: Why did these variants arise? Were they under selection pressure? And, is there compelling evidence to support genotyping these variants to better predict disease risk and prognosis? PMID:27037420

  17. Unlocking the Genetic Diversity of Maize Landraces with Doubled Haploids Opens New Avenues for Breeding

    PubMed Central

    Strigens, Alexander; Schipprack, Wolfgang; Reif, Jochen C.; Melchinger, Albrecht E.

    2013-01-01

    Landraces are valuable genetic resources for broadening the genetic base of elite germplasm in maize. Extensive exploitation of landraces has been hampered by their genetic heterogeneity and heavy genetic load. These limitations may be overcome by the in-vivo doubled haploid (DH) technique. A set of 132 DH lines derived from three European landraces and 106 elite flint (EF) lines were genotyped for 56,110 single nucleotide polymorphism (SNP) markers and evaluated in field trials at five locations in Germany in 2010 for several agronomic traits. In addition, the landraces were compared with synthetic populations produced by intermating DH lines derived from the respective landrace. Our objectives were to (1) evaluate the phenotypic and molecular diversity captured within DH lines derived from European landraces, (2) assess the breeding potential (usefulness) of DH lines derived from landraces to broaden the genetic base of the EF germplasm, and (3) compare the performance of each landrace with the synthetic population produced from the respective DH lines. Large genotypic variances among DH lines derived from landraces allowed the identification of DH lines with grain yields comparable to those of EF lines. Selected DH lines may thus be introgressed into elite germplasm without impairing its yield level. Large genetic distances of the DH lines to the EF lines demonstrated the potential of DH lines derived from landraces to broaden the genetic base of the EF germplasm. The comparison of landraces with their respective synthetic population showed no yield improvement and no reduction of phenotypic diversity. Owing to the low population structure and rapid decrease of linkage disequilibrium within populations of DH lines derived from landraces, these would be an ideal tool for association mapping. Altogether, the DH technology opens new opportunities for characterizing and utilizing the genetic diversity present in gene bank accessions of maize. PMID:23451190

  18. Genetically modified foods: a taste of the future.

    PubMed

    Lessick, Mira; Keithley, Joyce; Swanson, Barbara; Lemon, Betty

    2002-10-01

    Technologies for genetically modifying foods hold tremendous promise for meeting important public health challenges in this century. By keeping informed of the ongoing development of genetically modified foods, nurses can effectively educate patients about the benefits and risks of these foods and promote informed decision making. PMID:12830747

  19. Genetically Modified Organisms and Visceral Leishmaniasis

    PubMed Central

    Chhajer, Rudra; Ali, Nahid

    2014-01-01

    Vaccination is the most effective method of preventing infectious diseases. Since the eradication of small pox in 1976, many other potentially life compromising if not threatening diseases have been dealt with subsequently. This event was a major leap not only in the scientific world already burdened with many diseases but also in the mindset of the common man who became more receptive to novel treatment options. Among the many protozoan diseases, the leishmaniases have emerged as one of the largest parasite killers of the world, second only to malaria. There are three types of leishmaniasis namely cutaneous (CL), mucocutaneous (ML), and visceral (VL), caused by a group of more than 20 species of Leishmania parasites. Visceral leishmaniasis, also known as kala-azar is the most severe form and almost fatal if untreated. Since the first attempts at leishmanization, we have killed parasite vaccines, subunit protein, or DNA vaccines, and now we have live recombinant carrier vaccines and live attenuated parasite vaccines under various stages of development. Although some research has shown promising results, many more potential genes need to be evaluated as live attenuated vaccine candidates. This mini-review attempts to summarize the success and failures of genetically modified organisms used in vaccination against some of major parasitic diseases for their application in leishmaniasis. PMID:24860575

  20. Genetically modified crops and food security.

    PubMed

    Qaim, Matin; Kouser, Shahzad

    2013-01-01

    The role of genetically modified (GM) crops for food security is the subject of public controversy. GM crops could contribute to food production increases and higher food availability. There may also be impacts on food quality and nutrient composition. Finally, growing GM crops may influence farmers' income and thus their economic access to food. Smallholder farmers make up a large proportion of the undernourished people worldwide. Our study focuses on this latter aspect and provides the first ex post analysis of food security impacts of GM crops at the micro level. We use comprehensive panel data collected over several years from farm households in India, where insect-resistant GM cotton has been widely adopted. Controlling for other factors, the adoption of GM cotton has significantly improved calorie consumption and dietary quality, resulting from increased family incomes. This technology has reduced food insecurity by 15-20% among cotton-producing households. GM crops alone will not solve the hunger problem, but they can be an important component in a broader food security strategy. PMID:23755155

  1. Genetically modified plants and human health

    PubMed Central

    Key, Suzie; Ma, Julian K-C; Drake, Pascal MW

    2008-01-01

    Summary Genetically modified (or GM) plants have attracted a large amount of media attention in recent years and continue to do so. Despite this, the general public remains largely unaware of what a GM plant actually is or what advantages and disadvantages the technology has to offer, particularly with regard to the range of applications for which they can be used. From the first generation of GM crops, two main areas of concern have emerged, namely risk to the environment and risk to human health. As GM plants are gradually being introduced into the European Union there is likely to be increasing public concern regarding potential health issues. Although it is now commonplace for the press to adopt health campaigns, the information they publish is often unreliable and unrepresentative of the available scientific evidence. We consider it important that the medical profession should be aware of the state of the art, and, as they are often the first port of call for a concerned patient, be in a position to provide an informed opinion. This review will examine how GM plants may impact on human health both directly through applications targeted at nutrition and enhancement of recombinant medicine production but also indirectly, through potential effects on the environment. Finally, it will examine the most important opposition currently facing the worldwide adoption of this technology: public opinion. PMID:18515776

  2. Genetics of gene expression surveyed in maize, mouse and man.

    PubMed

    Schadt, Eric E; Monks, Stephanie A; Drake, Thomas A; Lusis, Aldons J; Che, Nam; Colinayo, Veronica; Ruff, Thomas G; Milligan, Stephen B; Lamb, John R; Cavet, Guy; Linsley, Peter S; Mao, Mao; Stoughton, Roland B; Friend, Stephen H

    2003-03-20

    Treating messenger RNA transcript abundances as quantitative traits and mapping gene expression quantitative trait loci for these traits has been pursued in gene-specific ways. Transcript abundances often serve as a surrogate for classical quantitative traits in that the levels of expression are significantly correlated with the classical traits across members of a segregating population. The correlation structure between transcript abundances and classical traits has been used to identify susceptibility loci for complex diseases such as diabetes and allergic asthma. One study recently completed the first comprehensive dissection of transcriptional regulation in budding yeast, giving a detailed glimpse of a genome-wide survey of the genetics of gene expression. Unlike classical quantitative traits, which often represent gross clinical measurements that may be far removed from the biological processes giving rise to them, the genetic linkages associated with transcript abundance affords a closer look at cellular biochemical processes. Here we describe comprehensive genetic screens of mouse, plant and human transcriptomes by considering gene expression values as quantitative traits. We identify a gene expression pattern strongly associated with obesity in a murine cross, and observe two distinct obesity subtypes. Furthermore, we find that these obesity subtypes are under the control of different loci. PMID:12646919

  3. Use of Genetic Effects and Genotype by Environmental Interactions for the Classification of Mexican Races of Maize

    PubMed Central

    Cervantes, Tarcicio S.; Goodman, Major M.; Casas, Eduardo D.; Rawlings, John O.

    1978-01-01

    To examine the questions of whether the additive and dominance effects present for morphological characters in racial crosses are of sufficient consistency and magnitude to allow such genetic effects to be used for racial classification, we used a diallel experiment among the 25 well-defined Mexican races of maize, which include the ancestral stocks of most commercial and genetic maize types. With such an experiment, genetic effects and genotype by environmental interactions for one or more characters can be used to measure genetic and adaptational or environmental similarity. We used average parental effects (general combining abilities), specific effects, and genotype by environmental effects of 21 characters from the diallel (grown at three locations) to group the Mexican races of maize. The groupings based upon average genetic effects and upon genotype by environmental interactions are more satisfactory than groupings based upon specific effects. The standard errors for genetic distances based upon specific (largely dominance) effects seem to be too high for practical use. Principal components analyses of the same data suggest a similar conclusion.—The groupings based upon average genetic effects are in general agreement with previous studies, with the exception of Maíz Dulce, which is grouped with the Cónicos, rather than being isolated from the other Mexican races of maize. PMID:17248866

  4. The genetic basis of natural variation for iron homeostasis in the maize IBM population

    PubMed Central

    2014-01-01

    Background Iron (Fe) deficiency symptoms in maize (Zea mays subsp. mays) express as leaf chlorosis, growth retardation, as well as yield reduction and are typically observed when plants grow in calcareous soils at alkaline pH. To improve our understanding of genotypical variability in the tolerance to Fe deficiency-induced chlorosis, the objectives of this study were to (i) determine the natural genetic variation of traits related to Fe homeostasis in the maize intermated B73 × Mo17 (IBM) population, (ii) to identify quantitative trait loci (QTLs) for these traits, and (iii) to analyze expression levels of genes known to be involved in Fe homeostasis as well as of candidate genes obtained from the QTL analysis. Results In hydroponically-grown maize, a total of 47 and 39 QTLs were detected for the traits recorded under limited and adequate supply of Fe, respectively. Conclusions From the QTL results, we were able to identify new putative candidate genes involved in Fe homeostasis under a deficient or adequate Fe nutritional status, like Ferredoxin class gene, putative ferredoxin PETF, metal tolerance protein MTP4, and MTP8. Furthermore, our expression analysis of candidate genes suggested the importance of trans-acting regulation for 2’-deoxymugineic acid synthase 1 (DMAS1), nicotianamine synthase (NAS3, NAS1), formate dehydrogenase 1 (FDH1), methylthioribose-1-phosphate isomerase (IDI2), aspartate/tyrosine/aromatic aminotransferase (IDI4), and methylthioribose kinase (MTK). PMID:24400634

  5. Genetically modified crops: Brazilian law and overview.

    PubMed

    Marinho, C D; Martins, F J O; Amaral Júnior, A T; Gonçalves, L S A; dos Santos, O J A P; Alves, D P; Brasileiro, B P; Peternelli, L A

    2014-01-01

    In Brazil, the first genetically modified (GM) crop was released in 1998, and it is estimated that 84, 78, and 50% of crop areas containing soybean, corn, and cotton, respectively, were transgenic in 2012. This intense and rapid adoption rate confirms that the choice to use technology has been the main factor in developing national agriculture. Thus, this review focuses on understanding these dynamics in the context of farmers, trade relations, and legislation. To accomplish this goal, a survey was conducted using the database of the National Cultivar Registry and the National Service for Plant Variety Protection of the Ministry of Agriculture, Livestock and Supply [Ministério da Agricultura, Pecuária e Abastecimento (MAPA)] between 1998 and October 13, 2013. To date, 36 events have been released: five for soybeans, 18 for corn, 12 for cotton, and one for beans. From these events, 1395 cultivars have been developed and registered: 582 for soybean, 783 for corn and 30 for cotton. Monsanto owns 73.05% of the technologies used to develop these cultivars, while the Dow AgroScience - DuPont partnership and Syngenta have 16.34 and 4.37% ownership, respectively. Thus, the provision of transgenic seeds by these companies is an oligopoly supported by legislation. Moreover, there has been a rapid replacement of conventional crops by GM crops, whose technologies belong almost exclusively to four multinational companies, with the major ownership by Monsanto. These results reflect a warning to the government of the increased dependence on multinational corporations for key agricultural commodities. PMID:25061747

  6. Genome-wide dissection of the maize ear genetic architecture using multiple populations.

    PubMed

    Xiao, Yingjie; Tong, Hao; Yang, Xiaohong; Xu, Shizhong; Pan, Qingchun; Qiao, Feng; Raihan, Mohammad Sharif; Luo, Yun; Liu, Haijun; Zhang, Xuehai; Yang, Ning; Wang, Xiaqing; Deng, Min; Jin, Minliang; Zhao, Lijun; Luo, Xin; Zhou, Yang; Li, Xiang; Liu, Jie; Zhan, Wei; Liu, Nannan; Wang, Hong; Chen, Gengshen; Cai, Ye; Xu, Gen; Wang, Weidong; Zheng, Debo; Yan, Jianbing

    2016-05-01

    Improvement of grain yield is an essential long-term goal of maize (Zea mays) breeding to meet continual and increasing food demands worldwide, but the genetic basis remains unclear. We used 10 different recombination inbred line (RIL) populations genotyped with high-density markers and phenotyped in multiple environments to dissect the genetic architecture of maize ear traits. Three methods were used to map the quantitative trait loci (QTLs) affecting ear traits. We found 17-34 minor- or moderate-effect loci that influence ear traits, with little epistasis and environmental interactions, totally accounting for 55.4-82% of the phenotypic variation. Four novel QTLs were validated and fine mapped using candidate gene association analysis, expression QTL analysis and heterogeneous inbred family validation. The combination of multiple different populations is a flexible and manageable way to collaboratively integrate widely available genetic resources, thereby boosting the statistical power of QTL discovery for important traits in agricultural crops, ultimately facilitating breeding programs. PMID:26715032

  7. Genetic control of maize shoot apical meristem architecture.

    PubMed

    Thompson, Addie M; Crants, James; Schnable, Patrick S; Yu, Jianming; Timmermans, Marja C P; Springer, Nathan M; Scanlon, Michael J; Muehlbauer, Gary J

    2014-07-01

    The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays, we investigated its morphology at multiple time points and identified three stages of growth. We measured meristem height, width, plastochron internode length, and associated traits from 86 individuals of the intermated B73 × Mo17 recombinant inbred line population. For meristem height-related traits, the parents exhibited markedly different phenotypes, with B73 being very tall, Mo17 short, and the population distributed between. In the outer cell layer, differences appeared to be related to number of cells rather than cell size. In contrast, B73 and Mo17 were similar in meristem width traits and plastochron internode length, with transgressive segregation in the population. Multiple loci (6-9 for each trait) were mapped, indicating meristem architecture is controlled by many regions; none of these coincided with previously described mutants impacting meristem development. Major loci for height and width explaining 16% and 19% of the variation were identified on chromosomes 5 and 8, respectively. Significant loci for related traits frequently coincided, whereas those for unrelated traits did not overlap. With the use of three near-isogenic lines, a locus explaining 16% of the parental variation in meristem height was validated. Published expression data were leveraged to identify candidate genes in significant regions. PMID:24855316

  8. Genetic Control of Maize Shoot Apical Meristem Architecture

    PubMed Central

    Thompson, Addie M.; Crants, James; Schnable, Patrick S.; Yu, Jianming; Timmermans, Marja C. P.; Springer, Nathan M.; Scanlon, Michael J.; Muehlbauer, Gary J.

    2014-01-01

    The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays, we investigated its morphology at multiple time points and identified three stages of growth. We measured meristem height, width, plastochron internode length, and associated traits from 86 individuals of the intermated B73 × Mo17 recombinant inbred line population. For meristem height-related traits, the parents exhibited markedly different phenotypes, with B73 being very tall, Mo17 short, and the population distributed between. In the outer cell layer, differences appeared to be related to number of cells rather than cell size. In contrast, B73 and Mo17 were similar in meristem width traits and plastochron internode length, with transgressive segregation in the population. Multiple loci (6−9 for each trait) were mapped, indicating meristem architecture is controlled by many regions; none of these coincided with previously described mutants impacting meristem development. Major loci for height and width explaining 16% and 19% of the variation were identified on chromosomes 5 and 8, respectively. Significant loci for related traits frequently coincided, whereas those for unrelated traits did not overlap. With the use of three near-isogenic lines, a locus explaining 16% of the parental variation in meristem height was validated. Published expression data were leveraged to identify candidate genes in significant regions. PMID:24855316

  9. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population1[W][OPEN

    PubMed Central

    Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; Dugard, Christopher K.; Held, Michael A.; Klimek, John F.; Shreve, Jacob T.; Fowler, Matthew; Ziebell, Angela; Davis, Mark F.; Decker, Stephen R.; Turner, Geoffrey B.; Mosier, Nathan S.; Springer, Nathan M.; Thimmapuram, Jyothi; Weil, Clifford F.; McCann, Maureen C.; Carpita, Nicholas C.

    2014-01-01

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. PMID:24972714

  10. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population

    SciTech Connect

    Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; Dugard, Christopher K.; Held, Michael A.; Klimek, John F.; Shreve, Jacob T.; Fowler, Matthew; Ziebell, Angela; Davis, Mark F.; Decker, Stephen R.; Turner, Geoffrey B.; Mosier, Nathan S.; Springer, Nathan M.; Thimmapuram, Jyothi; Weil, Clifford F.; McCann, Maureen C.; Carpita, Nicholas C.

    2014-06-27

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 x 3 Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282- member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. Finally, these results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass.

  11. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population

    DOE PAGESBeta

    Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; Dugard, Christopher K.; Held, Michael A.; Klimek, John F.; Shreve, Jacob T.; Fowler, Matthew; Ziebell, Angela; Davis, Mark F.; et al

    2014-06-27

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 x 3 Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yieldmore » was shared. A genome-wide association study for lignin abundance and sugar yield of the 282- member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. Finally, these results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass.« less

  12. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population.

    PubMed

    Penning, Bryan W; Sykes, Robert W; Babcock, Nicholas C; Dugard, Christopher K; Held, Michael A; Klimek, John F; Shreve, Jacob T; Fowler, Matthew; Ziebell, Angela; Davis, Mark F; Decker, Stephen R; Turner, Geoffrey B; Mosier, Nathan S; Springer, Nathan M; Thimmapuram, Jyothi; Weil, Clifford F; McCann, Maureen C; Carpita, Nicholas C

    2014-06-27

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. PMID:24972714

  13. Potential adverse health effects of genetically modified crops.

    PubMed

    Bakshi, Anita

    2003-01-01

    Genetically modified crops have the potential to eliminate hunger and starvation in millions of people, especially in developing countries because the genetic modification can produce large amounts of foods that are more nutritious. Large quantities are produced because genetically modified crops are more resistant to pests and drought. They also contain greater amounts of nutrients, such as proteins and vitamins. However, there are concerns about the safety of genetically modified crops. The concerns are that they may contain allergenic substances due to introduction of new genes into crops. Another concern is that genetic engineering often involves the use of antibiotic-resistance genes as "selectable markers" and this could lead to production of antibiotic-resistant bacterial strains that are resistant to available antibiotics. This would create a serious public health problem. The genetically modified crops might contain other toxic substances (such as enhanced amounts of heavy metals) and the crops might not be "substantially equivalent" in genome, proteome, and metabolome compared with unmodified crops. Another concern is that genetically modified crops may be less nutritious; for example, they might contain lower amounts of phytoestrogens, which protect against heart disease and cancer. The review of available literature indicates that the genetically modified crops available in the market that are intended for human consumption are generally safe; their consumption is not associated with serious health problems. However, because of potential for exposure of a large segment of human population to genetically modified foods, more research is needed to ensure that the genetically modified foods are safe for human consumption. PMID:12746139

  14. Methodological scheme for designing the monitoring of genetically modified crops at the regional scale.

    PubMed

    Graef, F; Züghart, W; Hommel, B; Heinrich, U; Stachow, U; Werner, A

    2005-12-01

    According to EC regulations the deliberate release of genetically modified (GM) crops into the agro-environment needs to be accompanied by environmental monitoring to detect potential adverse effects, e.g. unacceptable levels of gene flow from GM to non-GM crops, or adverse effects on single species or species groups thus reducing biodiversity. There is, however, considerable scientific and public debate on how GM crops should be monitored with sufficient accuracy, discussing questions of potential adverse effects, agro-environmental variables or indicators to be monitored and respective detection methods; Another basic component, the appropriate number and location of monitoring sites, is hardly considered. Currently, no consistent GM crop monitoring approach combines these components systematically. This study focuses on and integrates spatial agro-environmental aspects at a landscape level in order to design monitoring networks. Based on examples of environmental variables associated with the cropping of Bt-Maize (Zea maize L.), herbicide-tolerant (HT) winter oilseed rape (Brassica napus L.), HT sugar beet (Beta vulgaris L.), and starch-modified potato (Solanum tuberosum L.), we develop a transferable framework and assessment scheme that comprises anticipated adverse environmental effects, variables to be measured and monitoring methods. These we integrate with a rule-based GIS (geographic information system) analysis, applying widely available spatial area and point information from existing environmental networks. This is used to develop scenarios with optimised regional GM crop monitoring networks. PMID:16311819

  15. [Assessment of allergenicity of genetically modified food crops].

    PubMed

    Schauzu, M; Pöting, A; Rubin, D; Lampen, A

    2012-03-01

    The placing on the European Union's market of genetically modified crops requires authorization by the European Commission which is based on the proof that the derived foods are as safe as their conventional counterparts. The assessment of potential allergenicity is part of the necessary investigations recommended in the updated Guidance Document of the Scientific Panel on Genetically Modified Organisms (GMO) of the European Food Safety Authority (EFSA), which is based on internationally agreed recommendations. All genetically modified crops which so far have been authorized in the European Union were evaluated by the EFSA GMO Panel which considered it unlikely that their overall allergenicity has been altered. PMID:22373855

  16. Gene Flow in Genetically Modified Wheat

    PubMed Central

    Rieben, Silvan; Kalinina, Olena; Schmid, Bernhard; Zeller, Simon L.

    2011-01-01

    Understanding gene flow in genetically modified (GM) crops is critical to answering questions regarding risk-assessment and the coexistence of GM and non-GM crops. In two field experiments, we tested whether rates of cross-pollination differed between GM and non-GM lines of the predominantly self-pollinating wheat Triticum aestivum. In the first experiment, outcrossing was studied within the field by planting “phytometers” of one line into stands of another line. In the second experiment, outcrossing was studied over distances of 0.5–2.5 m from a central patch of pollen donors to adjacent patches of pollen recipients. Cross-pollination and outcrossing was detected when offspring of a pollen recipient without a particular transgene contained this transgene in heterozygous condition. The GM lines had been produced from the varieties Bobwhite or Frisal and contained Pm3b or chitinase/glucanase transgenes, respectively, in homozygous condition. These transgenes increase plant resistance against pathogenic fungi. Although the overall outcrossing rate in the first experiment was only 3.4%, Bobwhite GM lines containing the Pm3b transgene were six times more likely than non-GM control lines to produce outcrossed offspring. There was additional variation in outcrossing rate among the four GM-lines, presumably due to the different transgene insertion events. Among the pollen donors, the Frisal GM line expressing a chitinase transgene caused more outcrossing than the GM line expressing both a chitinase and a glucanase transgene. In the second experiment, outcrossing after cross-pollination declined from 0.7–0.03% over the test distances of 0.5–2.5 m. Our results suggest that pollen-mediated gene flow between GM and non-GM wheat might only be a concern if it occurs within fields, e.g. due to seed contamination. Methodologically our study demonstrates that outcrossing rates between transgenic and other lines within crops can be assessed using a phytometer approach and that gene-flow distances can be efficiently estimated with population-level PCR analyses. PMID:22216349

  17. Unraveling the genetic architecture of subtropical maize (Zea mays L.) lines to assess their utility in breeding programs

    PubMed Central

    2013-01-01

    Background Maize is an increasingly important food crop in southeast Asia. The elucidation of its genetic architecture, accomplished by exploring quantitative trait loci and useful alleles in various lines across numerous breeding programs, is therefore of great interest. The present study aimed to characterize subtropical maize lines using high-quality SNPs distributed throughout the genome. Results We genotyped a panel of 240 subtropical elite maize inbred lines and carried out linkage disequilibrium, genetic diversity, population structure, and principal component analyses on the generated SNP data. The mean SNP distance across the genome was 70 Kb. The genome had both high and low linkage disequilibrium (LD) regions; the latter were dominant in areas near the gene-rich telomeric portions where recombination is frequent. A total of 252 haplotype blocks, ranging in size from 1 to 15.8 Mb, were identified. Slow LD decay (200–300 Kb) at r 2  ≤ 0.1 across all chromosomes explained the selection of favorable traits around low LD regions in different breeding programs. The association mapping panel was characterized by strong population substructure. Genotypes were grouped into three distinct clusters with a mean genetic dissimilarity coefficient of 0.36. Conclusions The genotyped panel of subtropical maize lines characterized in this study should be useful for association mapping of agronomically important genes. The dissimilarity uncovered among genotypes provides an opportunity to exploit the heterotic potential of subtropical elite maize breeding lines. PMID:24330649

  18. Detection of genetically modified organisms in foods by protein- and DNA-based techniques: bridging the methods.

    PubMed

    van Duijn, Gert J; van Biert, Ria; Bleeker-Marcelis, Henriette; Van Boeijen, Ineke; Adan, Abdi Jama; Jhakrie, Soeniei; Hessing, Martin

    2002-01-01

    According to European Commission (EC) Regulation 1139/98, foods and food ingredients that are to be delivered to the final consumer in which either protein or DNA resulting from genetic modification is present, shall be subject to additional specific labeling requirements. Since 1994, genetically altered tomatoes, squash, potatoes, canola, cotton, and soy have been on the market. Recently, insect-resistant and herbicide-tolerant maize varieties have been introduced. Soy and maize are 2 of the most important vegetable crops in the world. During the past 4 years, both protein- and DNA-based methods have been developed and applied for detection of transgenic soy and maize, and their derivatives. For protein-based detection, specific monoclonal and polyclonal antibodies have been developed; for immunochemical detection, Western blot analysis and enzyme-linked immunosorbent assays are the most prominent examples. For detection of genetically modified organisms (GMOs) at the level of DNA, polymerase chain reaction-based methods are mainly used. For these reactions, highly specific primer sets are needed. This study compares the principally different methods. Specificity of methods and the possible risks of false-positive or false-negative results are considered in relation to sampling, matrix effects, and food processing procedures. In addition, quantitative aspects of protein- and DNA-based GM detection methods are presented and discussed. This is especially relevant as EC regulation 49/2000, which defines a threshold for an unintentional comingling of 1%, came into force on April 10, 2000. PMID:12083276

  19. Stable Patterns of CENH3 Occupancy Through Maize Lineages Containing Genetically Similar Centromeres.

    PubMed

    Gent, Jonathan I; Wang, Kai; Jiang, Jiming; Dawe, R Kelly

    2015-08-01

    While the approximate chromosomal position of centromeres has been identified in many species, little is known about the dynamics and diversity of centromere positions within species. Multiple lines of evidence indicate that DNA sequence has little or no impact in specifying centromeres in maize and in most multicellular organisms. Given that epigenetically defined boundaries are expected to be dynamic, we hypothesized that centromere positions would change rapidly over time, which would result in a diversity of centromere positions in isolated populations. To test this hypothesis, we used CENP-A/cenH3 (CENH3 in maize) chromatin immunoprecipitation to define centromeres in breeding pedigrees that included the B73 inbred as a common parent. While we found a diversity of CENH3 profiles for centromeres with divergent sequences that were not inherited from B73, the CENH3 profiles from centromeres that were inherited from B73 were indistinguishable from each other. We propose that specific genetic elements in centromeric regions favor or inhibit CENH3 accumulation, leading to reproducible patterns of CENH3 occupancy. These data also indicate that dramatic shifts in centromere position normally originate from accumulated or large-scale genetic changes rather than from epigenetic positional drift. PMID:26063660

  20. Recombination in diverse maize is stable, predictable, and associated with genetic load.

    PubMed

    Rodgers-Melnick, Eli; Bradbury, Peter J; Elshire, Robert J; Glaubitz, Jeffrey C; Acharya, Charlotte B; Mitchell, Sharon E; Li, Chunhui; Li, Yongxiang; Buckler, Edward S

    2015-03-24

    Among the fundamental evolutionary forces, recombination arguably has the largest impact on the practical work of plant breeders. Varying over 1,000-fold across the maize genome, the local meiotic recombination rate limits the resolving power of quantitative trait mapping and the precision of favorable allele introgression. The consequences of low recombination also theoretically extend to the species-wide scale by decreasing the power of selection relative to genetic drift, and thereby hindering the purging of deleterious mutations. In this study, we used genotyping-by-sequencing (GBS) to identify 136,000 recombination breakpoints at high resolution within US and Chinese maize nested association mapping populations. We find that the pattern of cross-overs is highly predictable on the broad scale, following the distribution of gene density and CpG methylation. Several large inversions also suppress recombination in distinct regions of several families. We also identify recombination hotspots ranging in size from 1 kb to 30 kb. We find these hotspots to be historically stable and, compared with similar regions with low recombination, to have strongly differentiated patterns of DNA methylation and GC content. We also provide evidence for the historical action of GC-biased gene conversion in recombination hotspots. Finally, using genomic evolutionary rate profiling (GERP) to identify putative deleterious polymorphisms, we find evidence for reduced genetic load in hotspot regions, a phenomenon that may have considerable practical importance for breeding programs worldwide. PMID:25775595

  1. Recombination in diverse maize is stable, predictable, and associated with genetic load

    PubMed Central

    Rodgers-Melnick, Eli; Bradbury, Peter J.; Elshire, Robert J.; Glaubitz, Jeffrey C.; Acharya, Charlotte B.; Mitchell, Sharon E.; Li, Chunhui; Li, Yongxiang; Buckler, Edward S.

    2015-01-01

    Among the fundamental evolutionary forces, recombination arguably has the largest impact on the practical work of plant breeders. Varying over 1,000-fold across the maize genome, the local meiotic recombination rate limits the resolving power of quantitative trait mapping and the precision of favorable allele introgression. The consequences of low recombination also theoretically extend to the species-wide scale by decreasing the power of selection relative to genetic drift, and thereby hindering the purging of deleterious mutations. In this study, we used genotyping-by-sequencing (GBS) to identify 136,000 recombination breakpoints at high resolution within US and Chinese maize nested association mapping populations. We find that the pattern of cross-overs is highly predictable on the broad scale, following the distribution of gene density and CpG methylation. Several large inversions also suppress recombination in distinct regions of several families. We also identify recombination hotspots ranging in size from 1 kb to 30 kb. We find these hotspots to be historically stable and, compared with similar regions with low recombination, to have strongly differentiated patterns of DNA methylation and GC content. We also provide evidence for the historical action of GC-biased gene conversion in recombination hotspots. Finally, using genomic evolutionary rate profiling (GERP) to identify putative deleterious polymorphisms, we find evidence for reduced genetic load in hotspot regions, a phenomenon that may have considerable practical importance for breeding programs worldwide. PMID:25775595

  2. Influence of Genetic Background on Anthocyanin and Copigment Composition and Behavior during Thermoalkaline Processing of Maize.

    PubMed

    Collison, Amy; Yang, Liyi; Dykes, Linda; Murray, Seth; Awika, Joseph M

    2015-06-10

    Visual color is a primary quality factor for foods purchase; identifying factors that influence in situ color quality of pigmented maize during processing is important. Twenty-four genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) were used to investigate the effect of pigment and copigment composition on color stability during nixtamalization and tortilla chip processing. The red/blue and blue samples generally contained higher proportions of acylated anthocyanins (mainly cyanidin-3-(6″-malonylglucoside)) than the red and purple color classes. Phenolic amides were the major extractable copigments in all samples (450-764 μg/g), with red samples containing the most putrescines and blue samples containing the most spermidines. Even though samples with higher proportions of acylated anthocyanins retained more pigments during processing, this did not relate to final product color quality. In general, the red/blue samples retained their color quality the best and thus are good candidates for genetic improvement for direct processing into alkalized products. PMID:26010030

  3. EXPRESSION AND INHERITANCE PATTERNS OF A MODIFIED PORCINE A-LACTALBUMIN TRANSGENE IN MAIZE KERNELS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A codon-adjusted version of a gene encoding the porcine milk protein alpha-lactalbumin was synthesized to create maize with improved nutritional quality. Three expression vectors containing the synthetic gene were constructed and transformed into maize callus by particle bombardment. The constructs ...

  4. Discovery and purification of a fungal protease secreted by Bipolaris zeicola that modifies maize seed endochitinase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Healthy maize seeds have two basic endochitinases, chitA and chitB, with antifungal properties. A comparison of the isoenzyme profiles of symptomatic fungal-infested maize seeds, removed at harvest from ears that we wound inoculated in the late milk stage of maturity with one of several common ear-...

  5. Genetic control of the number of leaves above the ear in maize.

    PubMed

    Freire, A I; Dias, K O G; Oliveira, L B V; Nalin, R S; Guedes, F L; Souza, J C

    2015-01-01

    In this study, we examined the genetic control of the number of leaves above the first ear in maize. The F₂ generations and the backcrosses were obtained from 2 contrasting lines for this trait. All generations were assessed in a completely randomized block design with 2 replications. The number of leaves above the ear was counted when the plants were in the tasseling stage at the level of plants per plot. Mean and variance components were estimated using the weighted least square method. We observed a predominance of non-additive effects in the genetic control of number of leaves above the ear. These results indicate that this trait shows high heritability. PMID:25730071

  6. Combinatorial genetic transformation generates a library of metabolic phenotypes for the carotenoid pathway in maize

    PubMed Central

    Zhu, Changfu; Naqvi, Shaista; Breitenbach, Jürgen; Sandmann, Gerhard; Christou, Paul; Capell, Teresa

    2008-01-01

    Combinatorial nuclear transformation is a novel method for the rapid production of multiplex-transgenic plants, which we have used to dissect and modify a complex metabolic pathway. To demonstrate the principle, we transferred 5 carotenogenic genes controlled by different endosperm-specific promoters into a white maize variety deficient for endosperm carotenoid synthesis. We recovered a diverse population of transgenic plants expressing different enzyme combinations and showing distinct metabolic phenotypes that allowed us to identify and complement rate-limiting steps in the pathway and to demonstrate competition between β-carotene hydroxylase and bacterial β-carotene ketolase for substrates in 4 sequential steps of the extended pathway. Importantly, this process allowed us to generate plants with extraordinary levels of β-carotene and other carotenoids, including complex mixtures of hydroxycarotenoids and ketocarotenoids. Combinatorial transformation is a versatile approach that could be used to modify any metabolic pathway and pathways controlling other biochemical, physiological, or developmental processes. PMID:19011084

  7. Crop management and agronomic context of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed Central

    Champion, G T; May, M J; Bennett, S; Brooks, D R; Clark, S J; Daniels, R E; Firbank, L G; Haughton, A J; Hawes, C; Heard, M S; Perry, J N; Randle, Z; Rossall, M J; Rothery, P; Skellern, M P; Scott, R J; Squire, G R; Thomas, M R

    2003-01-01

    The Farm Scale Evaluations of genetically modified herbicide-tolerant crops (GMHT) were conducted in the UK from 2000 to 2002 on beet (sugar and fodder), spring oilseed rape and forage maize. The management of the crops studied is described and compared with current conventional commercial practice. The distribution of field sites adequately represented the areas currently growing these crops, and the sample contained sites operated at a range of management intensities, including low intensity. Herbicide inputs were audited, and the active ingredients used and the rates and the timings of applications compared well with current practice for both GMHT and conventional crops. Inputs on sugar beet were lower than, and inputs on spring oilseed rape and forage maize were consistent with, national averages. Regression analysis of herbicide-application strategies and weed emergence showed that inputs applied by farmers increased with weed densities in beet and forage maize. GMHT crops generally received only one herbicide active ingredient per crop, later and fewer herbicide sprays and less active ingredient (for beet and maize) than the conventional treatments. The audit of inputs found no evidence of bias. PMID:14561315

  8. Crop management and agronomic context of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed

    Champion, G T; May, M J; Bennett, S; Brooks, D R; Clark, S J; Daniels, R E; Firbank, L G; Haughton, A J; Hawes, C; Heard, M S; Perry, J N; Randle, Z; Rossall, M J; Rothery, P; Skellern, M P; Scott, R J; Squire, G R; Thomas, M R

    2003-11-29

    The Farm Scale Evaluations of genetically modified herbicide-tolerant crops (GMHT) were conducted in the UK from 2000 to 2002 on beet (sugar and fodder), spring oilseed rape and forage maize. The management of the crops studied is described and compared with current conventional commercial practice. The distribution of field sites adequately represented the areas currently growing these crops, and the sample contained sites operated at a range of management intensities, including low intensity. Herbicide inputs were audited, and the active ingredients used and the rates and the timings of applications compared well with current practice for both GMHT and conventional crops. Inputs on sugar beet were lower than, and inputs on spring oilseed rape and forage maize were consistent with, national averages. Regression analysis of herbicide-application strategies and weed emergence showed that inputs applied by farmers increased with weed densities in beet and forage maize. GMHT crops generally received only one herbicide active ingredient per crop, later and fewer herbicide sprays and less active ingredient (for beet and maize) than the conventional treatments. The audit of inputs found no evidence of bias. PMID:14561315

  9. Haplotype structure strongly affects recombination in a maize genetic interval polymorphic for Helitron and retrotransposon insertions

    PubMed Central

    He, Limei; Dooner, Hugo K.

    2009-01-01

    We have asked here how the remarkable variation in maize haplotype structure affects recombination. We compared recombination across a genetic interval of 9S in 2 highly dissimilar heterozygotes that shared 1 parent. The genetic interval in the common haplotype is ≈100 kb long and contains 6 genes interspersed with gene-fragment-bearing Helitrons and retrotransposons that, together, comprise 70% of its length. In one heterozygote, most intergenic insertions are homozygous, although polymorphic, enabling us to determine whether any recombination junctions fall within them. In the other, most intergenic insertions are hemizygous and, thus, incapable of homologous recombination. Our analysis of the frequency and distribution of recombination in the interval revealed that: (i) Most junctions were circumscribed to the gene space, where they showed a highly nonuniform distribution. In both heterozygotes, more than half of the junctions fell in the stc1 gene, making it a clear recombination hotspot in the region. However, the genetic size of stc1 was 2-fold lower when flanked by a hemizygous 25-kb retrotransposon cluster. (ii) No junctions fell in the hypro1 gene in either heterozygote, making it a genic recombination coldspot. (iii) No recombination occurred within the gene fragments borne on Helitrons nor within retrotransposons, so neither insertion class contributes to the interval's genetic length. (iv) Unexpectedly, several junctions fell in an intergenic region not shared by all 3 haplotypes. (v) In general, the ability of a sequence to recombine correlated inversely with its methylation status. Our results show that haplotypic structural variability strongly affects the frequency and distribution of recombination events in maize. PMID:19416860

  10. The genetic basis of flecking and its relationship to disease resistance in the IBM maize mapping population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flecking is defined as a mild, often environmentally-dependent lesion phenotype observed on the leaves of several commonly used maize inbred lines. Anecdotal evidence suggests a link between flecking and enhanced broad-spectrum disease resistance. Neither the genetic basis underlying flecking nor ...

  11. Characterization of genetic diversity and linkage disequilibrium of ZmLOX4 and ZmLOX5 loci in maize.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize lipoxygenases (ZmLOXs) are well recognized as important players in plant defense against pathogens, especially in cross kingdom lipid communication with pathogenic fungi. This study is among the first to investigate genetic diversity at important gene paralogs ZmLOX4 and ZmLOX5 believed to be...

  12. Genetically Modified Crops Are Safe: Review

    MedlinePLUS

    ... as safe to eat as food from traditional plant-breeding methods To use the sharing features on this page, please enable ... modified crops that have been approved for commercial use in the United States, ... focus on a plant's characteristics rather than the process by which it ...

  13. Genetic Characterization and Linkage Disequilibrium Estimation of a Global Maize Collection Using SNP Markers

    PubMed Central

    Yan, Jianbing; Shah, Trushar; Warburton, Marilyn L.; Buckler, Edward S.; McMullen, Michael D.; Crouch, Jonathan

    2009-01-01

    A newly developed maize Illumina GoldenGate Assay with 1536 SNPs from 582 loci was used to genotype a highly diverse global maize collection of 632 inbred lines from temperate, tropical, and subtropical public breeding programs. A total of 1229 informative SNPs and 1749 haplotypes within 327 loci was used to estimate the genetic diversity, population structure, and familial relatedness. Population structure identified tropical and temperate subgroups, and complex familial relationships were identified within the global collection. Linkage disequilibrium (LD) was measured overall and within chromosomes, allelic frequency groups, subgroups related by geographic origin, and subgroups of different sample sizes. The LD decay distance differed among chromosomes and ranged between 1 to 10 kb. The LD distance increased with the increase of minor allelic frequency (MAF), and with smaller sample sizes, encouraging caution when using too few lines in a study. The LD decay distance was much higher in temperate than in tropical and subtropical lines, because tropical and subtropical lines are more diverse and contain more rare alleles than temperate lines. A core set of inbreds was defined based on haplotypes, and 60 lines capture 90% of the haplotype diversity of the entire panel. The defined core sets and the entire collection can be used widely for different research targets. PMID:20041112

  14. Genetic control of morphometric diversity in the maize shoot apical meristem

    PubMed Central

    Leiboff, Samuel; Li, Xianran; Hu, Heng-Cheng; Todt, Natalie; Yang, Jinliang; Li, Xiao; Yu, Xiaoqing; Muehlbauer, Gary J.; Timmermans, Marja C. P.; Yu, Jianming; Schnable, Patrick S.; Scanlon, Michael J.

    2015-01-01

    The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate genes. Analyses of candidate genes implicated in hormone transport, cell division and cell size confirm correlations between SAM morphology and trait-associated SNP alleles. Our data illustrate that the microscopic seedling SAM is predictive of adult phenotypes and that SAM morphometric variation is associated with genes not previously predicted to regulate SAM size. PMID:26584889

  15. Characterization, Genetic Variation, and Combining Ability of Maize Traits Relevant to the Production of Cellulosic Ethanol

    SciTech Connect

    Lorenz, A. J.; Coors, J. G.; de Leon, N.; Wolfrum, E. J.; Hames, B. R.; Sluiter, A. D.; Weimer, P. J.

    2009-01-01

    Maize (Zea mays L.) stover has been identified as an important feedstock for the production of cellulosic ethanol. Our objectives were to measure hybrid effect and combining ability patterns of traits related to cellulosic ethanol production, determine if germplasm and mutations used for silage production would also be beneficial for feedstock production, and examine relationships between traits that are relevant to selective breeding. We evaluated grain hybrids, germplasm bred for silage production, brown-midrib hybrids, and a leafy hybrid. Yield and composition traits were measured in four environments. There was a 53% difference in stover yield between commercial grain hybrids that were equivalent for other production-related traits. Silage germplasm may be useful for increasing stover yield and reducing lignin concentration. We found much more variation among hybrids than either in vitro ruminal fermentability or polysaccharide concentration. Correlations between traits were mostly favorable or nonexistent. Our results suggest that utilizing standing genetic variation of maize in breeding programs could substantially increase the amount of biofuels produced from stover per unit area of land.

  16. Complexity and Genetic Variability of Heat-Shock Protein Expression in Isolated Maize Microspores.

    PubMed Central

    Magnard, J. L.; Vergne, P.; Dumas, C.

    1996-01-01

    The expression of heat-shock proteins (HSPs) in isolated maize (Zea mays L.) microspores has been investigated using high-resolution two-dimensional electrophoresis coupled to immunodetection and fluorography of in vivo synthesized proteins. To this end, homogeneous and viable populations of microspores have been purified in sufficient amounts for molecular analysis from plants grown in controlled conditions. Appropriate conditions for thermal stress application have been defined. The analysis revealed that isolated microspores from maize display a classical heat-shock response characterized by the repression of the normal protein synthesis and the expression of a set of HSPs. A high complexity of the response was demonstrated, with numerous different HSPs being resolved in each known major HSP molecular weight class. However, the extent of this heat-shock response is limited in that some of these HSPs do not accumulate at high levels following temperature elevation. Comparative analysis of the heat-shock responses of microspores isolated from five genotypes demonstrated high levels of genetic variability. Furthermore, many HSPs were detected in microspores at control temperature, indicating a possible involvement of these proteins in pollen development at stages close to first pollen mitosis. PMID:12226349

  17. [A Study of the Relationship Among Genetic Distances, NIR Spectra Distances, and NIR-Based Identification Model Performance of the Seeds of Maize Iinbred Lines].

    PubMed

    Liu, Xu; Jia, Shi-qiang; Wang, Chun-ying; Liu, Zhe; Gu, Jian-cheng; Zhai, Wei; Li, Shao-ming; Zhang, Xiao-dong; Zhu, De-hai; Huang, Hua-jun; An, Dong

    2015-09-01

    This paper explored the relationship among genetic distances, NIR spectra distances and NIR-based identification model performance of the seeds of maize inbred lines. Using 3 groups (total 15 pairs) of maize inbred lines whose genetic distaches are different as experimental materials, we calculates the genetic distance between these seeds with SSR markers and uses Euclidean distance between distributed center points of maize NIR spectrum in the PCA space as the distances of NIR spectrum. BPR method is used to build identification model of inbred lines and the identification accuracy is used as a measure of model identification performance. The results showed that, the correlation of genetic distance and spectra distancesis 0.9868, and it has a correlation of 0.9110 with the identification accuracy, which is highly correlated. This means near-Infrared spectrum of seedscan reflect genetic relationship of maize inbred lines. The smaller the genetic distance, the smaller the distance of spectrum, the poorer ability of model to identify. In practical application, near infrared spectrum analysis technology has the potential to be used to analyze maize inbred genetic relations, contributing much to genetic breeding, identification of species, purity sorting and so on. What's more, when creating a NIR-based identification model, the impact of the maize inbred lines which have closer genetic relationship should be fully considered. PMID:26669157

  18. Genetic Design and Statistical Power of Nested Association Mapping in Maize

    PubMed Central

    Yu, Jianming; Holland, James B.; McMullen, Michael D.; Buckler, Edward S.

    2008-01-01

    We investigated the genetic and statistical properties of the nested association mapping (NAM) design currently being implemented in maize (26 diverse founders and 5000 distinct immortal genotypes) to dissect the genetic basis of complex quantitative traits. The NAM design simultaneously exploits the advantages of both linkage analysis and association mapping. We demonstrated the power of NAM for high-power cost-effective genome scans through computer simulations based on empirical marker data and simulated traits with different complexities. With common-parent-specific (CPS) markers genotyped for the founders and the progenies, the inheritance of chromosome segments nested within two adjacent CPS markers was inferred through linkage. Genotyping the founders with additional high-density markers enabled the projection of genetic information, capturing linkage disequilibrium information, from founders to progenies. With 5000 genotypes, 3079% of the simulated quantitative trait loci (QTL) were precisely identified. By integrating genetic design, natural diversity, and genomics technologies, this new complex trait dissection strategy should greatly facilitate endeavors to link molecular variation with phenotypic variation for various complex traits. PMID:18202393

  19. Detection limits of the strip test and PCR for genetically modified corn in Brazil.

    PubMed

    Nascimento, V E; Von Pinho, É V R; Von Pinho, R G; do Nascimento, A D

    2012-01-01

    Brazilian legislation establishes a labeling limit for products that contain more than 1% material from genetically modified organisms (GMOs). We assessed the sensitivity of the lateral flow strip test in detection of the GMO corn varieties Bt11 and MON810 and the specificity and sensitivity of PCR techniques for their detection. For the strip test, the GMO seeds were mixed with conventional seeds at levels of 0.2, 0.4 and 0.8% for Bt11, and 0.4, 0.8 and 1.6% for MON810. Three different methodologies were assessed and whole seeds, their endosperm and embryonic axis were used. For the PCR technique, the GMO seeds of each of the two varieties were mixed with conventional seeds at levels of 20, 10, 5, 2, 1, and 0.5%. The seeds were ground and the DNA extracted. For detection of the GMO material, specific primers were used for MON810 and Bt11 and maize zein as an endogenous control. The sensitivity of the strip test varied for both maize varieties and methodologies. The test was positive for Bt11 only at 0.8%, in contrast with the detection limit of 0.4% indicated by the manufacturer. In the multiplex PCR, the primers proved to be specific for the different varieties. These varieties were detected in samples with one GMO seed in 100. Thus, this technique proved to be efficient in detecting contaminations equal to or greater than 1%. PMID:22843069

  20. New multiplex PCR methods for rapid screening of genetically modified organisms in foods

    PubMed Central

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

  1. Detection of genetically modified organisms in foreign-made processed foods containing corn and potato.

    PubMed

    Monma, Kimio; Araki, Rie; Sagi, Naoki; Satoh, Masaki; Ichikawa, Hisatsugu; Satoh, Kazue; Tobe, Takashi; Kamata, Kunihiro; Hino, Akihiro; Saito, Kazuo

    2005-06-01

    Investigations of the validity of labeling regarding genetically modified (GM) products were conducted using polymerase chain reaction (PCR) methods for foreign-made processed foods made from corn and potato purchased in the Tokyo area and in the USA. Several kinds of GM crops were detected in 12 of 32 samples of processed corn samples. More than two GM events for which safety reviews have been completed in Japan were simultaneously detected in 10 samples. GM events MON810 and Bt11 were most frequently detected in the samples by qualitative PCR methods. MON810 was detected in 11 of the 12 samples, and Bt11 was detected in 6 of the 12 samples. In addition, Roundup Ready soy was detected in one of the 12 samples. On the other hand, CBH351, for which the safety assessment was withdrawn in Japan, was not detected in any of the 12 samples. A trial quantitative analysis was performed on six of the GM maize qualitatively positive samples. The estimated amounts of GM maize in these samples ranged from 0.2 to 2.8%, except for one sample, which contained 24.1%. For this sample, the total amount found by event-specific quantitative analysis was 23.8%. Additionally, Roundup Ready soy was detected in one sample of 21 potato-processed foods, although GM potatoes were not detected in any sample. PMID:16042293

  2. [Identification of genetically modified vegetable sources in food and feed using hydrogel oligonucleotide microchip].

    PubMed

    Griadunov, D A; Getman, I A; Chizhova, S I; Mikha?lovich, V M; Zasedatelev, A S; Romanov, G A

    2011-01-01

    A method of multiplex polymerase chain reaction (PCR) followed by the hybridization on a hydrogel oligonucleotide biochip was developed for simultaneous identification of ten different transgenic elements of plant DNA in feed and food products. The biochip contained 22 immobilized probes intended for (i) detection of plant DNA; (ii) plant species determination (soybean, maize, potato, rice); (iii) identification of transgenic elements, including 35S CaMV, 35S FMV, rice actine gene promoters, nos, 35S CaMV, ocs, pea rbcS1 gene terminators, and bar, gus, nptII marker genes. The limit of detection was 0.5% of genetically modified (GM) soybean and maize in analyzed samples. Identification of transgenic DNA in food and feed products using either the developed approach or real-time PCR led to virtually identical results. The assay can be used for selection of GM samples by screening food and feed products for subsequent quantitative determination of the GM component based on the identified transgene. PMID:22295567

  3. New multiplex PCR methods for rapid screening of genetically modified organisms in foods.

    PubMed

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

  4. Adiposity significantly modifies genetic risk for dyslipidemia.

    PubMed

    Cole, Christopher B; Nikpay, Majid; Lau, Paulina; Stewart, Alexandre F R; Davies, Robert W; Wells, George A; Dent, Robert; McPherson, Ruth

    2014-11-01

    Recent genome-wide association studies have identified multiple loci robustly associated with plasma lipids, which also contribute to extreme lipid phenotypes. However, these common genetic variants explain <12% of variation in lipid traits. Adiposity is also an important determinant of plasma lipoproteins, particularly plasma TGs and HDL cholesterol (HDLc) concentrations. Thus, interactions between genes and clinical phenotypes may contribute to this unexplained heritability. We have applied a weighted genetic risk score (GRS) for both plasma TGs and HDLc in two large cohorts at the extremes of BMI. Both BMI and GRS were strongly associated with these lipid traits. A significant interaction between obese/lean status and GRS was noted for each of TG (P(Interaction) = 2.87 × 10(-4)) and HDLc (P(Interaction) = 1.05 × 10(-3)). These interactions were largely driven by SNPs tagging APOA5, glucokinase receptor (GCKR), and LPL for TG, and cholesteryl ester transfer protein (CETP), GalNAc-transferase (GALNT2), endothelial lipase (LIPG), and phospholipid transfer protein (PLTP) for HDLc. In contrast, the GRSLDL cholesterol × adiposity interaction was not significant. Sexual dimorphism was evident for the GRSHDL on HDLc in obese (P(Interaction) = 0.016) but not lean subjects. SNP by BMI interactions may provide biological insight into specific genetic associations and missing heritability. PMID:25225679

  5. Genetic Control of Photoperiod Sensitivity in Maize Revealed by Joint Multiple Population Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced photoperiod sensitivity was critical to the evolution of broad geographical adaptability in maize, but modern tropical maize retains photoperiod sensitivity, hindering its use in temperate maize breeding programs. Many flowering time genes have been identified in diverse plant species, but t...

  6. Genetically Modified T Cells to Target Glioblastoma

    PubMed Central

    Krebs, Simone; Rodríguez-Cruz, Tania G.; DeRenzo, Christopher; Gottschalk, Stephen

    2013-01-01

    Despite advances in surgical procedures, radiation, and chemotherapy the outcome for patients with glioblastoma (GBM) remains poor. While GBM cells express antigens that are potentially recognized by T cells, GBMs prevent the induction of GBM-specific immune responses by creating an immunosuppressive microenvironment. The advent of gene transfer has allowed the rapid generation of antigen-specific T cells as well as T cells with enhanced effector function. Here we review recent advances in the field of cell therapy with genetically modified T cells and how these advances might improve outcomes for patients with GBM in the future. PMID:24427741

  7. Allelopathic effect of methanolic extracts of genetically modified and non-genetically modified canola on soybean.

    PubMed

    Syed, Kashmala; Shinwari, Zabta Khan

    2016-03-01

    This study on the effect of genetically modified (GM) and non-GM canola on soybean was carried out for physiological and biochemical biosafety assessment of GM canola. Methanolic extracts of GM and non-GM canola were assessed on seed germination and growth of soybean (Glycine max L.) under sterilized conditions. The extracts applied were of 3, 5, and 10% concentrations. The results showed that methanolic extracts of both GM and non-GM canola improved the germination percentage. However, germination rate index was significantly decreased with concomitant increase in mean germination time of soybean. A significant rate of decrease was observed in root fresh weight while increase in shoot length took place; when treatment of GM canola extracts were applied, however, no effect was observed in shoot fresh weight. A significant increase in protein contents, as well as phenolic, carotenoids, proline, and chlorophyll a content, was observed when different GM canola treatments (3, 5, and 10%) were applied to soybean; however, a significant rate of reduction in chlorophyll b content was observed by the application of GM canola treatment. Similar results were observed for superoxide dismutase, peroxidase, and catalase activities. A significant increase in the sugar content levels was observed when GM canola treatments (3, 5, and 10%) were applied to soybean. PMID:24105070

  8. Extensive genetic diversity and low linkage disequilibrium within the COMT locus in maize exotic populations.

    PubMed

    Chen, Yongsheng; Blanco, Michael; Ji, Qing; Frei, Ursula Karoline; Lübberstedt, Thomas

    2014-05-01

    The caffeic acid 3-O-methytransferase (COMT) gene is a prime candidate for cell wall digestibility improvement based on the characterization of brown midrib-3 mutants. We compared the genetic diversity and linkage disequilibrium at this locus between exotic populations sampled within the Germplasm Enhancement of Maize (GEM) project and 70 inbred lines. In total, we investigated 55 exotic COMT alleles and discovered more than 400 polymorphisms in a 2.2 kb region with pairwise nucleotide diversity (π) up to 0.017, much higher than reported π values of various genes in inbred lines. The ratio of non-synonymous to synonymous SNPs was 3:1 in exotic populations, and significantly higher than the 1:1 ratio for inbred lines. Selection tests detected selection signature in this gene in both pools, but with different evolution patterns. The linkage disequilibrium decay in exotic populations was at least four times more rapid than for inbred lines with r²>0.1 persisting only up to 100 bp. In conclusion, the alleles sampled in the GEM Project offer a valuable genetic resource to broaden genetic variation for the COMT gene, and likely other genes, in inbred background. Moreover, the low linkage disequilibrium makes this material suitable for high resolution association analyses. PMID:24656337

  9. Physical and Genetic Mapping of Chromosome 9s in Maize Using Mutations with Terminal Deficiencies

    PubMed Central

    Chao, S.; Gardiner, J. M.; Melia-Hancock, S.; Coe-Jr., E. H.

    1996-01-01

    Deletion mapping was employed to determine the physical order of five morphological variants, pyd1, yg2, wd1, v28 and v31, with respect to restriction fragment length polymorphism (RFLP) markers located at the distal end of chromosome 9S in maize. The genetic materials used were a series of terminal-deficiency mutants, newly derived with MCCLINTOCK's original stocks developed in the 1940s, via break-age-fusion-bridge cycles. A combined physical map and genetic map has been constructed based on data gathered from both genetic complementation tests and RFLP analysis. The location of v31 in relation to RFLP markers was further determined by interval mapping. The physical distance between the healed telomeric end and the most distal RFLP marker in two terminal-deficiency lines was established by using pulsed field gel electrophoresis and verified by Bal31 digestion. The results from this study set a foundation for studies on the mechanism of healing of broken chromosome ends in higher plants. PMID:8844164

  10. Rapid amplification of genetically modified organisms using a circular ferrofluid-driven PCR microchip.

    PubMed

    Sun, Yi; Kwok, Yien-Chian; Foo-Peng Lee, Peter; Nguyen, Nam-Trung

    2009-07-01

    The use of genetically modified organisms (GMOs) as food and in food products is becoming more and more widespread. Polymerase chain reaction (PCR) technology is extensively used for the detection of GMOs in food products in order to verify compliance with labeling requirements. In this paper, we present a novel close-loop ferrofluid-driven PCR microchip for rapid amplification of GMOs. The microchip was fabricated in polymethyl methacrylate by CO2 laser ablation and was integrated with three temperature zones. PCR solution was contained in a circular closed microchannel and was driven by magnetic force generated by an external magnet through a small oil-based ferrofluid plug. Successful amplification of genetically modified soya and maize were achieved in less than 13 min. This PCR microchip combines advantages of cycling flexibility and quick temperature transitions associated with two existing microchip PCR techniques, and it provides a cost saving and less time-consuming way to conduct preliminary screening of GMOs. PMID:19399482

  11. A statistical assessment of differences and equivalences between genetically modified and reference plant varieties

    PubMed Central

    2011-01-01

    Background Safety assessment of genetically modified organisms is currently often performed by comparative evaluation. However, natural variation of plant characteristics between commercial varieties is usually not considered explicitly in the statistical computations underlying the assessment. Results Statistical methods are described for the assessment of the difference between a genetically modified (GM) plant variety and a conventional non-GM counterpart, and for the assessment of the equivalence between the GM variety and a group of reference plant varieties which have a history of safe use. It is proposed to present the results of both difference and equivalence testing for all relevant plant characteristics simultaneously in one or a few graphs, as an aid for further interpretation in safety assessment. A procedure is suggested to derive equivalence limits from the observed results for the reference plant varieties using a specific implementation of the linear mixed model. Three different equivalence tests are defined to classify any result in one of four equivalence classes. The performance of the proposed methods is investigated by a simulation study, and the methods are illustrated on compositional data from a field study on maize grain. Conclusions A clear distinction of practical relevance is shown between difference and equivalence testing. The proposed tests are shown to have appropriate performance characteristics by simulation, and the proposed simultaneous graphical representation of results was found to be helpful for the interpretation of results from a practical field trial data set. PMID:21324199

  12. Is genetically modified crop the answer for the next green revolution?

    PubMed

    Basu, Saikat Kumar; Dutta, Madhuleema; Goyal, Aakash; Bhowmik, Pankaj Kumar; Kumar, Jitendra; Nandy, Sanjib; Scagliusi, Sandra Mansun; Prasad, Rajib

    2010-01-01

    Post-green revolution advances made in biotechnology paved the way of cultivating the high-yielding, stress and disease resistant genetically modified (GM) varieties of wheat, rice, maize cotton and several other crops. The recent rapid commercialization of the genetically modified crops in Asia, Americas and Australia indicates the potentiality of this new technology. GM crops give higher yields and are rich in nutritional values containing vitamins and minerals and can thus can help to alleviate hunger and malnutrition of the growing population in the under developed and developing countries. It could also be possible to develop more biotic and abiotic stress resistant genotypes in these crops where it was difficult to develop due to the unavailability of genes of resistance in the crossing germplasms. However, further research and investigations are needed to popularize the cultivation of these crops in different parts of the world. This review provides an insight of the impact of GM crops on contemporary agriculture across the past few decades, traces its' history across time, highlights new achievements and breakthroughs and discusses the future implication of this powerful technology in the coming few decades. PMID:21865874

  13. Genetically modified plants for tactical systems applications

    NASA Astrophysics Data System (ADS)

    Stewart, C. Neal, Jr.

    2002-08-01

    Plants are ubiquitous in the environment and have the ability to respond to their environment physiologically and through altered gene expression profiles (they cannot walk away). In addition, plant genetic transformation techniques and genomic information in plants are becoming increasingly advanced. We have been performing research to express the jellyfish green fluorescent protein (GFP) in plants. GFP emits green light when excited by blue or UV light. In addition, my group and collaborators have developed methods to detect GFP in plants by contact instruments and at a standoff. There are several tactical uses for this technology. Some obvious applications are using plants as sentinels for detecting biological and chemical warfare agents or their derivatives from a remote platform, as well as detecting explosives. Another tactical application is covert monitoring using individual plants. Different methods to detect GFP in transgenic plants will be discussed.

  14. The Genetic Architecture of Maize (Zea mays L.) Kernel Weight Determination

    PubMed Central

    Prado, Santiago Alvarez; López, César G.; Senior, M. Lynn; Borrás, Lucas

    2014-01-01

    Individual kernel weight is an important trait for maize yield determination. We have identified genomic regions controlling this trait by using the B73xMo17 population; however, the effect of genetic background on control of this complex trait and its physiological components is not yet known. The objective of this study was to understand how genetic background affected our previous results. Two nested stable recombinant inbred line populations (N209xMo17 and R18xMo17) were designed for this purpose. A total of 408 recombinant inbred lines were genotyped and phenotyped at two environments for kernel weight and five other traits related to kernel growth and development. All traits showed very high and significant (P < 0.001) phenotypic variability and medium-to-high heritability (0.60−0.90). When N209xMo17 and R18xMo17 were analyzed separately, a total of 23 environmentally stable quantitative trait loci (QTL) and five epistatic interactions were detected for N209xMo17. For R18xMo17, 59 environmentally stable QTL and 17 epistatic interactions were detected. A joint analysis detected 14 stable QTL regardless of the genetic background. Between 57 and 83% of detected QTL were population specific, denoting medium-to-high genetic background effects. This percentage was dependent on the trait. A meta-analysis including our previous B73xMo17 results identified five relevant genomic regions deserving further characterization. In summary, our grain filling traits were dominated by small additive QTL with several epistatic and few environmental interactions and medium-to-high genetic background effects. This study demonstrates that the number of detected QTL and additive effects for different physiologically related grain filling traits need to be understood relative to the specific germplasm. PMID:25237113

  15. Genetically Modified Food: Knowledge and Attitude of Teachers and Students

    NASA Astrophysics Data System (ADS)

    Mohapatra, Animesh K.; Priyadarshini, Deepika; Biswas, Antara

    2010-10-01

    The concepts behind the technology of genetic modification of organisms and its applications are complex. A diverse range of opinions, public concern and considerable media interest accompanies the subject. This study explores the knowledge and attitudes of science teachers and senior secondary biology students about the application of a rapidly expanding technology, genetic engineering, to food production. The results indicated significant difference in understanding of concepts related with genetically engineered food stuffs between teachers and students. The most common ideas about genetically modified food were that cross bred plants and genetically modified plants are not same, GM organisms are produced by inserting a foreign gene into a plant or animal and are high yielding. More teachers thought that genetically engineered food stuffs were unsafe for the environment. Both teachers and students showed number of misconceptions, for example, the pesticidal proteins produced by GM organisms have indirect effects through bioaccumulation, induces production of allergic proteins, genetic engineering is production of new genes, GM plants are leaky sieves and that transgenes are more likely to introgress into wild species than mutated species. In general, more students saw benefits while teachers were cautious about the advantages of genetically engineered food stuffs.

  16. Gene flow scenarios with transgenic maize in Mexico.

    PubMed

    Serratos-Hernández, José-Antonio; Islas-Gutiérrez, Fabián; Buendía-Rodríguez, Enrique; Berthaud, Julien

    2004-01-01

    Maize diversity is widespread in Mexico and it has been stewarded by campesinos in small communities until the present. With the arrival of transgenic maize, the objective of this study is to analyze possible scenarios that could result if genetically modified maize were not regulated and openly available in Mexico. By applying a simple logistic model based on the conditions of maize production in Mexico, the dispersion of transgenic maize in different situations within fields of farmers is described. In traditional open systems of freely exchanged seed within communities it is concluded that the most likely outcome of GM maize release is the incorporation of transgenes in the genome of Mexican germplasm and possibly in that of teosinte. PMID:15901097

  17. Implantation of Vascular Grafts Lined with Genetically Modified Endothelial Cells

    NASA Astrophysics Data System (ADS)

    Wilson, James M.; Birinyi, Louis K.; Salomon, Robert N.; Libby, Peter; Callow, Allan D.; Mulligan, Richard C.

    1989-06-01

    The possibility of using the vascular endothelial cell as a target for gene replacement therapy was explored. Recombinant retroviruses were used to transduce the lacZ gene into endothelial cells harvested from mongrel dogs. Prosthetic vascular grafts seeded with the genetically modified cells were implanted as carotid interposition grafts into the dogs from which the original cells were harvested. Analysis of the graft 5 weeks after implantation revealed genetically modified endothelial cells lining the luminal surface of the graft. This technology could be used in the treatment of atherosclerosis disease and the design of new drug delivery systems.

  18. MS-based analytical methodologies to characterize genetically modified crops.

    PubMed

    García-Cañas, Virginia; Simó, Carolina; León, Carlos; Ibáñez, Elena; Cifuentes, Alejandro

    2011-01-01

    The development of genetically modified crops has had a great impact on the agriculture and food industries. However, the development of any genetically modified organism (GMO) requires the application of analytical procedures to confirm the equivalence of the GMO compared to its isogenic non-transgenic counterpart. Moreover, the use of GMOs in foods and agriculture faces numerous criticisms from consumers and ecological organizations that have led some countries to regulate their production, growth, and commercialization. These regulations have brought about the need of new and more powerful analytical methods to face the complexity of this topic. In this regard, MS-based technologies are increasingly used for GMOs analysis to provide very useful information on GMO composition (e.g., metabolites, proteins). This review focuses on the MS-based analytical methodologies used to characterize genetically modified crops (also called transgenic crops). First, an overview on genetically modified crops development is provided, together with the main difficulties of their analysis. Next, the different MS-based analytical approaches applied to characterize GM crops are critically discussed, and include "-omics" approaches and target-based approaches. These methodologies allow the study of intended and unintended effects that result from the genetic transformation. This information is considered to be essential to corroborate (or not) the equivalence of the GM crop with its isogenic non-transgenic counterpart. PMID:21500243

  19. High Genetic Variability of Herbivore-Induced Volatile Emission within a Broad Range of Maize Inbred Lines1

    PubMed Central

    Degen, Thomas; Dillmann, Christine; Marion-Poll, Frédéric; Turlings, Ted C.J.

    2004-01-01

    Maize plants (Zea mays) attacked by caterpillars release a mixture of odorous compounds that attract parasitic wasps, natural enemies of the herbivores. We assessed the genetic variability of these induced volatile emissions among 31 maize inbred lines representing a broad range of genetic diversity used by breeders in Europe and North America. Odors were collected from young plants that had been induced by injecting them with caterpillar regurgitant. Significant variation among lines was found for all 23 volatile compounds included in the analysis: the lines differed enormously in the total amount of volatiles emitted and showed highly variable odor profiles distinctive of each genotype. Principal component analysis performed on the relative quantities of particular compounds within the blend revealed clusters of highly correlated volatiles, which may share common metabolic pathways. European and American lines belonging to established heterotic groups were loosely separated from each other, with the most clear-cut difference in the typical release of (E)-β-caryophyllene by European lines. There was no correlation between the distances among the lines based on their odor profiles and their respective genetic distances previously assessed by neutral RFLP markers. This most comprehensive study to date on intraspecific variation in induced odor emission by maize plants provides a further example of the remarkably high genetic diversity conserved within this important crop plant. A better understanding of the genetic control of induced odor emissions may help in the development of maize varieties particularly attractive to parasitoids and other biological control agents and perhaps more repellent for herbivores. PMID:15299140

  20. Huntingtin Interacting Proteins Are Genetic Modifiers of Neurodegeneration

    PubMed Central

    Becklin, Robert R; Chettier, Rakesh; Bell, Russell; Phansalkar, Amit; Strand, Andrew; Torcassi, Cameron; Savage, Justin; Hurlburt, Anthony; Cha, Guang-Ho; Ukani, Lubna; Chepanoske, Cindy Lou; Zhen, Yuejun; Sahasrabudhe, Sudhir; Olson, James; Kurschner, Cornelia; Ellerby, Lisa M; Peltier, John M; Botas, Juan; Hughes, Robert E

    2007-01-01

    Huntington's disease (HD) is a fatal neurodegenerative condition caused by expansion of the polyglutamine tract in the huntingtin (Htt) protein. Neuronal toxicity in HD is thought to be, at least in part, a consequence of protein interactions involving mutant Htt. We therefore hypothesized that genetic modifiers of HD neurodegeneration should be enriched among Htt protein interactors. To test this idea, we identified a comprehensive set of Htt interactors using two complementary approaches: high-throughput yeast two-hybrid screening and affinity pull down followed by mass spectrometry. This effort led to the identification of 234 high-confidence Htt-associated proteins, 104 of which were found with the yeast method and 130 with the pull downs. We then tested an arbitrary set of 60 genes encoding interacting proteins for their ability to behave as genetic modifiers of neurodegeneration in a Drosophila model of HD. This high-content validation assay showed that 27 of 60 orthologs tested were high-confidence genetic modifiers, as modification was observed with more than one allele. The 45% hit rate for genetic modifiers seen among the interactors is an order of magnitude higher than the 1%4% typically observed in unbiased genetic screens. Genetic modifiers were similarly represented among proteins discovered using yeast two-hybrid and pull-down/mass spectrometry methods, supporting the notion that these complementary technologies are equally useful in identifying biologically relevant proteins. Interacting proteins confirmed as modifiers of the neurodegeneration phenotype represent a diverse array of biological functions, including synaptic transmission, cytoskeletal organization, signal transduction, and transcription. Among the modifiers were 17 loss-of-function suppressors of neurodegeneration, which can be considered potential targets for therapeutic intervention. Finally, we show that seven interacting proteins from among 11 tested were able to co-immunoprecipitate with full-length Htt from mouse brain. These studies demonstrate that high-throughput screening for protein interactions combined with genetic validation in a model organism is a powerful approach for identifying novel candidate modifiers of polyglutamine toxicity. PMID:17500595

  1. Zeaxanthin is bioavailable from genetically modified zeaxanthin-rich potatoes.

    PubMed

    Bub, Achim; Möseneder, Jutta; Wenzel, Gerhard; Rechkemmer, Gerhard; Briviba, Karlis

    2008-03-01

    The carotenoid zeaxanthin accumulates in the human macula lutea and protects retinal cells from blue light damage. However, zeaxanthin intake from food sources is low. Increasing zeaxanthin in common foods such as potatoes by traditional plant breeding or by genetic engineering could contribute to an increased intake of this carotenoid and, consequently, to a decreased risk of age-related macular degeneration. Our aim was to investigate whether zeaxanthin from genetically modified zeaxanthin-rich potatoes is bioavailable in humans. Three men participated in this randomized, controlled double-blinded, crossover pilot study. All subjects consumed 1,100 g of mashed potatoes, either genetically modified (Solanum tuberosum L. var. Baltica GM47/18; 3 mg zeaxanthin) or wild-type control potatoes (Solanum tuberosum L. var. Baltica; 0.14 mg zeaxanthin). A second treatment was followed after a 7-day wash-out period. The concentration of zeaxanthin was significantly increased in chylomicrons after consumption of genetically modified potatoes and 0.27 mg of the 3 mg zeaxanthin dose could be detected in chylomicrons. Consumption of control potatoes had no effect on concentrations of zeaxanthin in chylomicrons. After normalization of chylomicron zeaxanthin for plasma triacylglycerol, the time course of zeaxanthin concentrations peaked at 7 h after consumption of genetically modified potatoes. There were no significant differences in the concentrations of other major potato carotenoids such as lutein and beta-carotene in chylomicrons after consumption of genetically modified and wild type control potatoes. Thus, consumption of zeaxanthin-rich potatoes significantly increases chylomicron zeaxanthin concentrations suggesting that potentially such potatoes could be used as an important dietary source of zeaxanthin. PMID:18320254

  2. MaizeGDB, the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

  3. GenAnneal: Genetically modified Simulated Annealing

    NASA Astrophysics Data System (ADS)

    Tsoulos, Ioannis G.; Lagaris, Isaac E.

    2006-05-01

    A modification of the standard Simulated Annealing (SA) algorithm is presented for finding the global minimum of a continuous multidimensional, multimodal function. We report results of computational experiments with a set of test functions and we compare to methods of similar structure. The accompanying software accepts objective functions coded both in Fortran 77 and C++. Program summaryTitle of program:GenAnneal Catalogue identifier:ADXI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXI_v1_0 Program available from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer for which the program is designed and others on which it has been tested: The tool is designed to be portable in all systems running the GNU C++ compiler Installation: University of Ioannina, Greece on Linux based machines Programming language used:GNU-C++, GNU-C, GNU Fortran 77 Memory required to execute with typical data: 200 KB No. of bits in a word: 32 No. of processors used: 1 Has the code been vectorized or parallelized?: No No. of bytes in distributed program, including test data, etc.:84 885 No. of lines in distributed program, including test data, etc.:14 896 Distribution format: tar.gz Nature of physical problem: A multitude of problems in science and engineering are often reduced to minimizing a function of many variables. There are instances that a local optimum does not correspond to the desired physical solution and hence the search for a better solution is required. Local optimization techniques are frequently trapped in local minima. Global optimization is hence the appropriate tool. For example, solving a non-linear system of equations via optimization, employing a "least squares" type of objective, one may encounter many local minima that do not correspond to solutions (i.e. they are far from zero). Typical running time: Depending on the objective function. Method of solution: We modified the process of step selection that the traditional Simulated Annealing employs and instead we used a global technique based on grammatical evolution.

  4. REGISTRATION OF MAIZE GERMPLASM LINE GEMS-0067

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEMS-0067 is a partially inbred germplasm line released by Truman State University (TSU) in accordance with the Germplasm Enhancement of Maize (GEM) protocol. This line is being released for use in the development of genetically diverse, elite, amylomaize class VII parental lines possessing modifie...

  5. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive ...

  6. Chemical characteristics and volatile profile of genetically modified peanut cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic engineering has been used to modify peanut varieties for improving agronomic performance and pest resistance. The flavor of peanut seed is an important characteristic influencing consumer acceptance. It is important that the flavor of the peanut varieties is at least maintained during the ...

  7. Chemical characteristics and volatile profile of genetically modified peanut cultivars.

    PubMed

    Ng, Ee Chin; Dunford, Nurhan T; Chenault, Kelly

    2008-10-01

    Genetic engineering has been used to modify peanut cultivars for improving agronomic performance and pest resistance. Food products developed through genetic engineering have to be assessed for their safety before approval for human consumption. Preservation of desirable chemical, flavor and aroma attributes of the peanut cultivars during the genetic modifications is critical for acceptance of genetically modified peanuts (GMP) by the food industry. Hence, the main objective of this study is to examine chemical characteristics and volatile profile of GMP. The genetically modified peanut cultivars, 188, 540 and 654 were obtained from the USDA-ARS in Stillwater, Oklahoma. The peanut variety Okrun was examined as a control. The volatile analysis was performed using a gas chromatograph/mass spectrometer (GC/MS) equipped with an olfactory detector. The peanut samples were also analyzed for their moisture, ash, protein, sugar and oil compositions. Experimental results showed that the variations in nutritional composition of peanut lines examined in this study were within the values reported for existing cultivars. There were minor differences in volatile profile among the samples. The implication of this study is significant, since it shows that peanut cultivars with greater pest and fungal resistance were successfully developed without major changes in their chemical characteristics. PMID:19000610

  8. Genetically modified crops in a 10-generation feeding trial on Japanese quails--Evaluation of its influence on birds' performance and body composition.

    PubMed

    Sartowska, K E; Korwin-Kossakowska, A; Sender, G

    2015-12-01

    The effect of genetically modified (GM) feed components comprising soya bean meal and maize on the performance indices (reproduction, survival rate, growth, egg production, relative weight of chosen internal organs, and basic chemical composition of breast muscle and egg yolk) of Japanese quails was investigated during a 10-generation trial. A total number of 8,438 healthy quail chicks were used in the course of the trial. In each generation, birds were maintained in 3 experimental groups differing in the main feed components, i.e. 1) GM soya (Roundup Ready) and non-GM maize, 2) GM maize (MON810) and non-GM soya, and 3) non-GM soya and maize. The different feeds used did not influence any of the biological hatch indices, survival rate, or BW of young or adult quails. With regard to egg-laying performance, the GM maize group showed a better laying percentage and a higher egg mass production compared to the other groups; the GM soya group showed reduced average egg mass compared to the other groups, whereas the overall egg production level was the same as in the control group. Results showed a higher relative weight of breast muscle and gizzard in birds fed GM maize compared to the control group, whereas live BW and the relative weights of liver and heart were not different among groups. Meat from the GM soya group showed higher protein and lower fat levels compared to the control group. In the case of egg yolk, its chemical composition in the experimental groups did not differ from the control group. Even though some differences were found among the feeding groups, none could be judged as a negative influence of GM maize or GM soya in feed on the birds or final consumer products over 10 generations of Japanese quails. PMID:26475068

  9. An Efficient Vector System to Modify Cells Genetically

    PubMed Central

    Han, Huamin; Liu, Qingjun; He, Wen; Ong, Kristy; Liu, Xiaoli; Gao, Bin

    2011-01-01

    The transfer of foreign genes into mammalian cells has been essential for understanding the functions of genes and mechanisms of genetic diseases, for the production of coding proteins and for gene therapy applications. Currently, the identification and selection of cells that have received transferred genetic material can be accomplished by methods, including drug selection, reporter enzyme detection and GFP imaging. These methods may confer antibiotic resistance, or be disruptive, or require special equipment. In this study, we labeled genetically modified cells with a cell surface biotinylation tag by co-transfecting cells with BirA, a biotin ligase. The modified cells can be quickly isolated for downstream applications using a simple streptavidin bead method. This system can also be used to screen cells expressing two sets of genes from separate vectors. PMID:22096482

  10. The Genetic Basis of Natural Variation in Kernel Size and Related Traits Using a Four-Way Cross Population in Maize.

    PubMed

    Chen, Jiafa; Zhang, Luyan; Liu, Songtao; Li, Zhimin; Huang, Rongrong; Li, Yongming; Cheng, Hongliang; Li, Xiantang; Zhou, Bo; Wu, Suowei; Chen, Wei; Wu, Jianyu; Ding, Junqiang

    2016-01-01

    Kernel size is an important component of grain yield in maize breeding programs. To extend the understanding on the genetic basis of kernel size traits (i.e., kernel length, kernel width and kernel thickness), we developed a set of four-way cross mapping population derived from four maize inbred lines with varied kernel sizes. In the present study, we investigated the genetic basis of natural variation in seed size and other components of maize yield (e.g., hundred kernel weight, number of rows per ear, number of kernels per row). In total, ten QTL affecting kernel size were identified, three of which (two for kernel length and one for kernel width) had stable expression in other components of maize yield. The possible genetic mechanism behind the trade-off of kernel size and yield components was discussed. PMID:27070143

  11. The Genetic Basis of Natural Variation in Kernel Size and Related Traits Using a Four-Way Cross Population in Maize

    PubMed Central

    Liu, Songtao; Li, Zhimin; Huang, Rongrong; Li, Yongming; Cheng, Hongliang; Li, Xiantang; Zhou, Bo; Wu, Suowei; Chen, Wei; Wu, Jianyu; Ding, Junqiang

    2016-01-01

    Kernel size is an important component of grain yield in maize breeding programs. To extend the understanding on the genetic basis of kernel size traits (i.e., kernel length, kernel width and kernel thickness), we developed a set of four-way cross mapping population derived from four maize inbred lines with varied kernel sizes. In the present study, we investigated the genetic basis of natural variation in seed size and other components of maize yield (e.g., hundred kernel weight, number of rows per ear, number of kernels per row). In total, ten QTL affecting kernel size were identified, three of which (two for kernel length and one for kernel width) had stable expression in other components of maize yield. The possible genetic mechanism behind the trade-off of kernel size and yield components was discussed. PMID:27070143

  12. The genetic architecture of zinc and iron content in maize grains as revealed by QTL mapping and meta-analysis

    PubMed Central

    Jin, Tiantian; Zhou, Jinfeng; Chen, Jingtang; Zhu, Liying; Zhao, Yongfeng; Huang, Yaqun

    2013-01-01

    Micronutrient malnutrition, especially zinc (Zn) and iron (Fe) deficiency in diets, has aroused worldwide attention. Biofortification of food crops has been considered as a promising approach for alleviating this deficiency. Quantitative trait locus (QTL) analysis was performed to dissect the genetic mechanism of Zn and Fe content in maize grains using a total of 218 F2:3 families derived from a cross between inbred lines 178 and P53. Meta-analysis was used to integrate genetic maps and detect Meta-QTL (MQTL) across several independent QTL researches for traits related to Zn or Fe content. Five significant QTLs and 10 MQTLs were detected. Two informative genomic regions, bins 2.07 and 2.08, showed a great importance for Zn and Fe content QTLs. The correlation between Zn and Fe level in maize grains was proposed by MQTLs as 8 of the 10 involved both traits. The results of this study suggest that QTL mapping and meta-analysis is an effective approach to understand the genetic basis of Zn and Fe accumulation in maize grains. PMID:24273427

  13. The genetic architecture of zinc and iron content in maize grains as revealed by QTL mapping and meta-analysis.

    PubMed

    Jin, Tiantian; Zhou, Jinfeng; Chen, Jingtang; Zhu, Liying; Zhao, Yongfeng; Huang, Yaqun

    2013-09-01

    Micronutrient malnutrition, especially zinc (Zn) and iron (Fe) deficiency in diets, has aroused worldwide attention. Biofortification of food crops has been considered as a promising approach for alleviating this deficiency. Quantitative trait locus (QTL) analysis was performed to dissect the genetic mechanism of Zn and Fe content in maize grains using a total of 218 F2:3 families derived from a cross between inbred lines 178 and P53. Meta-analysis was used to integrate genetic maps and detect Meta-QTL (MQTL) across several independent QTL researches for traits related to Zn or Fe content. Five significant QTLs and 10 MQTLs were detected. Two informative genomic regions, bins 2.07 and 2.08, showed a great importance for Zn and Fe content QTLs. The correlation between Zn and Fe level in maize grains was proposed by MQTLs as 8 of the 10 involved both traits. The results of this study suggest that QTL mapping and meta-analysis is an effective approach to understand the genetic basis of Zn and Fe accumulation in maize grains. PMID:24273427

  14. Genetic, evolutionary and plant breeding insights from the domestication of maize.

    PubMed

    Hake, Sarah; Ross-Ibarra, Jeffrey

    2015-01-01

    The natural history of maize began nine thousand years ago when Mexican farmers started to collect the seeds of the wild grass, teosinte. Invaluable as a food source, maize permeated Mexican culture and religion. Its domestication eventually led to its adoption as a model organism, aided in large part by its large chromosomes, ease of pollination and growing agricultural importance. Genome comparisons between varieties of maize, teosinte and other grasses are beginning to identify the genes responsible for the domestication of modern maize and are also providing ideas for the breeding of more hardy varieties. PMID:25807085

  15. HYBRIDIZATION STUDY BETWEEN GENETICALLY MODIFIED BRASSICA NAPUS AND NON-GENETICALLY MODIFIED B. NAPUS AND B. RAPA

    EPA Science Inventory

    Gene exchange between cultivated crops and wild species has gained significance in recent years because of concerns regarding the potential for gene flow between genetically modified (GM) crops and their domesticated and wild relatives. As part of our ecological effects of gene ...

  16. Detecting un-authorized genetically modified organisms (GMOs) and derived materials.

    PubMed

    Holst-Jensen, Arne; Bertheau, Yves; de Loose, Marc; Grohmann, Lutz; Hamels, Sandrine; Hougs, Lotte; Morisset, Dany; Pecoraro, Sven; Pla, Maria; Van den Bulcke, Marc; Wulff, Doerte

    2012-01-01

    Genetically modified plants, in the following referred to as genetically modified organisms or GMOs, have been commercially grown for almost two decades. In 2010 approximately 10% of the total global crop acreage was planted with GMOs (James, 2011). More than 30 countries have been growing commercial GMOs, and many more have performed field trials. Although the majority of commercial GMOs both in terms of acreage and specific events belong to the four species: soybean, maize, cotton and rapeseed, there are another 20+ species where GMOs are commercialized or in the pipeline for commercialization. The number of GMOs cultivated in field trials or for commercial production has constantly increased during this time period. So have the number of species, the number of countries involved, the diversity of novel (added) genetic elements and the global trade. All of these factors contribute to the increasing complexity of detecting and correctly identifying GMO derived material. Many jurisdictions, including the European Union (EU), legally distinguish between authorized (and therefore legal) and un-authorized (and therefore illegal) GMOs. Information about the developments, field trials, authorizations, cultivation, trade and observations made in the official GMO control laboratories in different countries around the world is often limited, despite several attempts such as the OECD BioTrack for voluntary dissemination of data. This lack of information inevitably makes it challenging to detect and identify GMOs, especially the un-authorized GMOs. The present paper reviews the state of the art technologies and approaches in light of coverage, practicability, sensitivity and limitations. Emphasis is put on exemplifying practical detection of un-authorized GMOs. Although this paper has a European (EU) bias when examples are given, the contents have global relevance. PMID:22333321

  17. Genotyping and phenotyping of an epigenetic modifier Unstable factor for orange1 (Ufo1) in maize

    NASA Astrophysics Data System (ADS)

    Bowersox, Karisa; Chopra, Surinder

    2012-02-01

    Pericarp color 1 is a model system for the study of epigenetic gene regulation. It has more than 100 alleles that contribute to the color of the pericarp and cob glume of maize. Unstable factor for orange 1 (Ufo1) is a spontaneous dominant mutation that leads to a gain in pigmentation due to a decrease in methylation in p1 genes. This decrease in methylation of cytosine in the DNA leads to changes in chromatin structure. Finding the mechanism for this spontaneous mutation can lead to way of preventing the mutation increasing production colorless maize for food production. Through genotyping and phenotyping fine gene mapping, gene expression and whole genome profiling can be accomplished for plants with the Ufo1 mutation present.

  18. MaizeGDB Community Curation Tools

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. The success of the MaizeGDB project largely can be attributed to the involvement of the community of maize geneticists. Members of the community have (1) made their data available by contributing to MaizeGD...

  19. Combining Quantitative Genetics Approaches with Regulatory Network Analysis to Dissect the Complex Metabolism of the Maize Kernel1[OPEN

    PubMed Central

    Wen, Weiwei; Liu, Haijun; Yang, Ning; Luo, Jie; Xiao, Yingjie; Pan, Qingchun; Tohge, Takayuki; Fernie, Alisdair R.; Yan, Jianbing

    2016-01-01

    Metabolic quantitative trait locus (QTL) studies have allowed us to better understand the genetic architecture underlying naturally occurring plant metabolic variance. Here, we use two recombinant inbred line (RIL) populations to dissect the genetic architecture of natural variation of 155 metabolites measured in the mature maize (Zea mays) kernel. Overall, linkage mapping identified 882 metabolic QTLs in both RIL populations across two environments, with an average of 2.1 QTLs per metabolite. A large number of metabolic QTLs (more than 65%) were identified with moderate effects (r2 = 2.1%–10%), while a small portion (less than 35%) showed major effects (r2 > 10%). Epistatic interactions between these identified loci were detected for more than 30% of metabolites (with the proportion of phenotypic variance ranging from 1.6% to 37.8%), implying that genetic epistasis is not negligible in determining metabolic variation. In total, 57 QTLs were validated by our previous genome-wide association study on the same metabolites that provided clues for exploring the underlying genes. A gene regulatory network associated with the flavonoid metabolic pathway was constructed based on the transcriptional variations of 28,769 genes in kernels (15 d after pollination) of 368 maize inbred lines. A large number of genes (34 of 58) in this network overlapped with previously defined genes controlled by maize PERICARP COLOR1, while three of them were identified here within QTL intervals for multiple flavonoids. The deeply characterized RIL populations, elucidation of metabolic phenotypes, and identification of candidate genes lay the foundation for maize quality improvement. PMID:26556794

  20. GENETIC VARIANCE AND BREEDING POTENTIAL OF PHYTATE AND INORGANIC PHOSPHORUS IN A MAIZE POPULATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed phosphorus (P) is predominantly bound in the organic compound phytate making the bioavailability of P in maize-based diets poor. Decreasing phytate and increasing inorganic P (Pi; an available form of P) concentrations in maize grain would be desirable to help solve associated environmental an...

  1. 78 FR 37201 - Pioneer Hi-Bred International, Inc.; Determination of Nonregulated Status of Maize Genetically...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... Register on February 27, 2013 (78 FR 13312-13313, Docket No. APHIS-2012-0026), APHIS announced the... Animal and Plant Health Inspection Service Pioneer Hi-Bred International, Inc.; Determination of... determination that a maize line developed by Pioneer Hi-Bred International Inc., designated as maize event...

  2. Genetic Characterization and Linkage Disequilibrium Estimation of a Global Maize Collection Using SNP Markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A newly developed maize Illumina GoldenGate Assay with 1536 SNPs from 582 candidate genes was used to genotype a highly diverse global maize collection of 632 inbred lines from temperate, tropical, and subtropical public breeding programs. A total of 1229 informative SNPs and 1785 haplotypes were ...

  3. Genetic and physical fine mapping of Scmv2, a potyvirus resistance gene in maize.

    PubMed

    Ingvardsen, Christina Roenn; Xing, Yongzhong; Frei, Ursula Karoline; Lübberstedt, Thomas

    2010-05-01

    Sugarcane mosaic virus (SCMV) is an important virus pathogen both in European and Chinese maize production, causing serious losses in grain and forage yield in susceptible cultivars. Two major resistance loci confer resistance to SCMV, one located on chromosome 3 (Scmv2) and one on chromosome 6 (Scmv1). We developed a large isogenic mapping population segregating in the Scmv2, but not the Scmv1 region, to minimize genetic variation potentially affecting expression of SCMV resistance. We fine mapped Scmv2 to a region of 0.28 cM, covering a physical distance of 1.3426 Mb, and developed six new polymorphic SSR markers based on publicly available BAC sequences within this region. At present, we still have three recombinants left between Scmv2 and the nearest polymorphic marker on either side of the Scmv2 locus. The region showed synteny to a 1.6 Mb long sequence on chromosome 12 in rice. Analysis of the public B73 BAC library as well as the syntenic rice region did not reveal any similarity to known resistance genes. However, four new candidate genes with a possible involvement in movement of virus were detected. PMID:20155410

  4. Analysis of genetic and epigenetic effects of maize seeds in response to heavy metal (Zn) stress.

    PubMed

    Erturk, Filiz Aygun; Agar, Guleray; Arslan, Esra; Nardemir, Gokce

    2015-07-01

    Conditions of environmental stress are known to lead genetic and epigenetic variability in plants. DNA methylation is one of the important epigenetic mechanisms and plays a critical role in epigenetic control of gene expression. Thus, the aim of the study was to investigate the alteration of genome methylation induced by zinc stress by using coupled restriction enzyme digestion-random amplification (CRED-RA) technique in maize (Zea mays L.) seedlings. In addition, to determine the effect of zinc on mitotic activity and phytohormone level, high-pressure liquid chromatography (HPLC) and mitotic index analysis were utilized. According to the results, mitotic index decreased in all concentrations of zinc except for 5 mM dose and chromosome aberrations such as c-mitosis, stickiness, and anaphase bridges were determined. It was also observed that increasing concentrations of zinc caused an increase in methylation patterns and decrease in gibberellic acid (GA), zeatin (ZA), and indole acetic acid (IAA) levels in contrast to abscisic acid (ABA) level. Especially increasing of ABA levels under zinc stress may be a part of the defense system against heavy metal accumulation in plants. PMID:25703614

  5. Phenotypic, genetic and molecular characterization of a maize low phytic acid mutant (lpa241).

    PubMed

    Pilu, R; Panzeri, D; Gavazzi, G; Rasmussen, S K; Consonni, G; Nielsen, E

    2003-10-01

    Phytic acid, myo-inositol 1,2,3,4,5,6-hexakisphosphate, is the major storage compound of phosphorous (P) in plants, predominantly accumulating in seeds (up to 4-5% of dry weight) and pollen. In cereals, phytic acid is deposited in embryo and aleurone grain tissues as a mixed "phytate" salt of potassium and magnesium, although phytates contain other mineral cations such as iron and zinc. During germination, phytates are broken down by the action of phytases, releasing their P, minerals and myo-inositol which become available to the growing seedling. Phytic acid represents an anti-nutritional factor for animals, and isolation of maize low phytic acid ( lpa) mutants provides a novel approach to study its biochemical pathway and to tackle the nutritional problems associated with it. Following chemical mutagenesis of pollen, we have isolated a viable recessive mutant named lpa 241 showing about 90% reduction of phytic acid and about a tenfold increase in seed-free phosphate content. Although germination rate was decreased by about 30% compared to wild-type, developement of mutant plants was apparentely unaffected. The results of the genetic, biochemical and molecular characterization experiments carried out by SSR mapping, MDD-HPLC and RT-PCR are consistent with a mutation affecting the MIPS1S gene, coding for the first enzyme of the phytic acid biosynthetic pathway. PMID:14523526

  6. Evaluation of plasmid and genomic DNA calibrants used for the quantification of genetically modified organisms.

    PubMed

    Caprioara-Buda, M; Meyer, W; Jeynov, B; Corbisier, P; Trapmann, S; Emons, H

    2012-07-01

    The reliable quantification of genetically modified organisms (GMOs) by real-time PCR requires, besides thoroughly validated quantitative detection methods, sustainable calibration systems. The latter establishes the anchor points for the measured value and the measurement unit, respectively. In this paper, the suitability of two types of DNA calibrants, i.e. plasmid DNA and genomic DNA extracted from plant leaves, for the certification of the GMO content in reference materials as copy number ratio between two targeted DNA sequences was investigated. The PCR efficiencies and coefficients of determination of the calibration curves as well as the measured copy number ratios for three powder certified reference materials (CRMs), namely ERM-BF415e (NK603 maize), ERM-BF425c (356043 soya), and ERM-BF427c (98140 maize), originally certified for their mass fraction of GMO, were compared for both types of calibrants. In all three systems investigated, the PCR efficiencies of plasmid DNA were slightly closer to the PCR efficiencies observed for the genomic DNA extracted from seed powders rather than those of the genomic DNA extracted from leaves. Although the mean DNA copy number ratios for each CRM overlapped within their uncertainties, the DNA copy number ratios were significantly different using the two types of calibrants. Based on these observations, both plasmid and leaf genomic DNA calibrants would be technically suitable as anchor points for the calibration of the real-time PCR methods applied in this study. However, the most suitable approach to establish a sustainable traceability chain is to fix a reference system based on plasmid DNA. PMID:22638881

  7. Outcrossing potential between 11 important genetically modified crops and the Chilean vascular flora.

    PubMed

    Sánchez, Miguel A; Cid, Pablo; Navarrete, Humberto; Aguirre, Carlos; Chacón, Gustavo; Salazar, Erika; Prieto, Humberto

    2016-02-01

    The potential impact of genetically modified (GM) crops on biodiversity is one of the main concerns in an environmental risk assessment (ERA). The likelihood of outcrossing and pollen-mediated gene flow from GM crops and non-GM crops are explained by the same principles and depend primarily on the biology of the species. We conducted a national-scale study of the likelihood of outcrossing between 11 GM crops and vascular plants in Chile by use of a systematized database that included cultivated, introduced and native plant species in Chile. The database included geographical distributions and key biological and agronomical characteristics for 3505 introduced, 4993 native and 257 cultivated (of which 11 were native and 246 were introduced) plant species. Out of the considered GM crops (cotton, soya bean, maize, grape, wheat, rice, sugar beet, alfalfa, canola, tomato and potato), only potato and tomato presented native relatives (66 species total). Introduced relative species showed that three GM groups were formed having: a) up to one introduced relative (cotton and soya bean), b) up to two (rice, grape, maize and wheat) and c) from two to seven (sugar beet, alfalfa, canola, tomato and potato). In particular, GM crops presenting introduced noncultivated relative species were canola (1 relative species), alfalfa (up to 4), rice (1), tomato (up to 2) and potato (up to 2). The outcrossing potential between species [OP; scaled from 'very low' (1) to 'very high' (5)] was developed, showing medium OPs (3) for GM-native relative interactions when they occurred, low (2) for GMs and introduced noncultivated and high (4) for the grape-Vitis vinifera GM-introduced cultivated interaction. This analytical tool might be useful for future ERA for unconfined GM crop release in Chile. PMID:26052925

  8. A literature review on the safety assessment of genetically modified plants.

    PubMed

    Domingo, Jos L; Gin Bordonaba, Jordi

    2011-05-01

    In recent years, there has been a notable concern on the safety of genetically modified (GM) foods/plants, an important and complex area of research, which demands rigorous standards. Diverse groups including consumers and environmental Non Governmental Organizations (NGO) have suggested that all GM foods/plants should be subjected to long-term animal feeding studies before approval for human consumption. In 2000 and 2006, we reviewed the information published in international scientific journals, noting that the number of references concerning human and animal toxicological/health risks studies on GM foods/plants was very limited. The main goal of the present review was to assess the current state-of-the-art regarding the potential adverse effects/safety assessment of GM plants for human consumption. The number of citations found in databases (PubMed and Scopus) has dramatically increased since 2006. However, new information on products such as potatoes, cucumber, peas or tomatoes, among others was not available. Corn/maize, rice, and soybeans were included in the present review. An equilibrium in the number research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was currently observed. Nevertheless, it should be noted that most of these studies have been conducted by biotechnology companies responsible of commercializing these GM plants. These findings suggest a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies. All this recent information is herein critically reviewed. PMID:21296423

  9. Copy number ratios determined by two digital polymerase chain reaction systems in genetically modified grains

    NASA Astrophysics Data System (ADS)

    Pérez Urquiza, M.; Acatzi Silva, A. I.

    2014-02-01

    Three certified reference materials produced from powdered seeds to measure the copy number ratio sequences of p35S/hmgA in maize containing MON 810 event, p35S/Le1 in soybeans containing GTS 40-3-2 event and DREB1A/acc1 in wheat were produced according to the ISO Guides 34 and 35. In this paper, we report digital polymerase chain reaction (dPCR) protocols, performance parameters and results of copy number ratio content of genetically modified organisms (GMOs) in these materials using two new dPCR systems to detect and quantify molecular deoxyribonucleic acid: the BioMark® (Fluidigm) and the OpenArray® (Life Technologies) systems. These technologies were implemented at the National Institute of Metrology in Mexico (CENAM) and in the Reference Center for GMO Detection from the Ministry of Agriculture (CNRDOGM), respectively. The main advantage of this technique against the more-used quantitative polymerase chain reaction (qPCR) is that it generates an absolute number of target molecules in the sample, without reference to standards or an endogenous control, which is very useful when not much information is available for new developments or there are no standard reference materials in the market as in the wheat case presented, or when it was not possible to test the purity of seeds as in the maize case presented here. Both systems reported enhanced productivity, increased reliability and reduced instrument footprint. In this paper, the performance parameters and uncertainty of measurement obtained with both systems are presented and compared.

  10. Comparison of Conventional, Modified Single Seed Descent, and Double Haploid Breeding Methods for Maize Inbred Line Development Using GEM Breeding Crosses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Good choice of germplasm, breeding methods, and careful evaluation are essential for maize inbred line and hybrid development. Choice of germplasm is particularly important since it may limit genetic gain given even the best breeding methodology and selection strategies. Exotic germplasm has the pot...

  11. Risk Assessment of Genetically Engineered Maize Resistant to Diabrotica spp.: Influence on Above-Ground Arthropods in the Czech Republic.

    PubMed

    Svobodová, Zdeňka; Skoková Habuštová, Oxana; Hutchison, William D; Hussein, Hany M; Sehnal, František

    2015-01-01

    Transgenic maize MON88017, expressing the Cry3Bb1 toxin from Bacillus thuringiensis (Bt maize), confers resistance to corn rootworms (Diabrotica spp.) and provides tolerance to the herbicide glyphosate. However, prior to commercialization, substantial assessment of potential effects on non-target organisms within agroecosystems is required. The MON88017 event was therefore evaluated under field conditions in Southern Bohemia in 2009-2011, to detect possible impacts on the above-ground arthropod species. The study compared MON88017, its near-isogenic non-Bt hybrid DK315 (treated or not treated with the soil insecticide Dursban 10G) and two non-Bt reference hybrids (KIPOUS and PR38N86). Each hybrid was grown on five 0.5 ha plots distributed in a 14-ha field with a Latin square design. Semiquantitative ELISA was used to verify Cry3Bb1 toxin levels in the Bt maize. The species spectrum of non-target invertebrates changed during seasons and was affected by weather conditions. The thrips Frankliniella occidentalis was the most abundant species in all three successive years. The next most common species were aphids Rhopalosiphum padi and Metopolophium dirhodum. Frequently observed predators included Orius spp. and several species within the Coccinellidae. Throughout the three-year study, analysis of variance indicated some significant differences (P<0.05). Multivariate analysis showed that the abundance and diversity of plant dwelling insects was similar in maize with the same genetic background, for both Bt (MON88017) and non-Bt (DK315) untreated or insecticide treated. KIPOUS and PR38N86 showed some differences in species abundance relative to the Bt maize and its near-isogenic hybrid. However, the effect of management regime on arthropod community was insignificant and accounted only for a negligible portion of the variability. PMID:26083254

  12. Risk Assessment of Genetically Engineered Maize Resistant to Diabrotica spp.: Influence on Above-Ground Arthropods in the Czech Republic

    PubMed Central

    Svobodová, Zdeňka; Skoková Habuštová, Oxana; Hutchison, William D.; Hussein, Hany M.; Sehnal, František

    2015-01-01

    Transgenic maize MON88017, expressing the Cry3Bb1 toxin from Bacillus thuringiensis (Bt maize), confers resistance to corn rootworms (Diabrotica spp.) and provides tolerance to the herbicide glyphosate. However, prior to commercialization, substantial assessment of potential effects on non-target organisms within agroecosystems is required. The MON88017 event was therefore evaluated under field conditions in Southern Bohemia in 2009–2011, to detect possible impacts on the above-ground arthropod species. The study compared MON88017, its near-isogenic non-Bt hybrid DK315 (treated or not treated with the soil insecticide Dursban 10G) and two non-Bt reference hybrids (KIPOUS and PR38N86). Each hybrid was grown on five 0.5 ha plots distributed in a 14-ha field with a Latin square design. Semiquantitative ELISA was used to verify Cry3Bb1 toxin levels in the Bt maize. The species spectrum of non-target invertebrates changed during seasons and was affected by weather conditions. The thrips Frankliniella occidentalis was the most abundant species in all three successive years. The next most common species were aphids Rhopalosiphum padi and Metopolophium dirhodum. Frequently observed predators included Orius spp. and several species within the Coccinellidae. Throughout the three-year study, analysis of variance indicated some significant differences (P<0.05). Multivariate analysis showed that the abundance and diversity of plant dwelling insects was similar in maize with the same genetic background, for both Bt (MON88017) and non-Bt (DK315) untreated or insecticide treated. KIPOUS and PR38N86 showed some differences in species abundance relative to the Bt maize and its near-isogenic hybrid. However, the effect of management regime on arthropod community was insignificant and accounted only for a negligible portion of the variability. PMID:26083254

  13. Characterization of Genetic Diversity and Linkage Disequilibrium of ZmLOX4 and ZmLOX5 Loci in Maize

    PubMed Central

    De La Fuente, Gerald N.; Murray, Seth C.; Isakeit, Thomas; Park, Yong-Soon; Yan, Yuanxin; Warburton, Marilyn L.; Kolomiets, Michael V.

    2013-01-01

    Maize (Zea mays L.) lipoxygenases (ZmLOXs) are well recognized as important players in plant defense against pathogens, especially in cross kingdom lipid communication with pathogenic fungi. This study is among the first to investigate genetic diversity at important gene paralogs ZmLOX4 and ZmLOX5. Sequencing of these genes in 400 diverse maize lines showed little genetic diversity and low linkage disequilibrium in the two genes. Importantly, we identified one inbred line in which ZmLOX5 has a disrupted open reading frame, a line missing ZmLOX5, and five lines with a duplication of ZmLOX5. Tajima's D test suggests that both ZmLOX4 and ZmLOX5 have been under neutral selection. Further investigation of haplotype data revealed that within the ZmLOX family members only ZmLOX12, a monocot specific ZmLOX, showed strong linkage disequilibrium that extends further than expected in maize. Linkage disequilibrium patterns at these loci of interest are crucial for future candidate gene association mapping studies. ZmLOX4 and ZmLOX5 mutations and copy number variants are under further investigation for crop improvement. PMID:23365644

  14. Discrimination of genetically modified sugar beets based on terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Tao; Li, Zhi; Yin, Xianhua; Hu, Fangrong; Hu, Cong

    2016-01-01

    The objective of this paper was to apply terahertz (THz) spectroscopy combined with chemometrics techniques for discrimination of genetically modified (GM) and non-GM sugar beets. In this paper, the THz spectra of 84 sugar beet samples (36 GM sugar beets and 48 non-GM ones) were obtained by using terahertz time-domain spectroscopy (THz-TDS) system in the frequency range from 0.2 to 1.2 THz. Three chemometrics methods, principal component analysis (PCA), discriminant analysis (DA) and discriminant partial least squares (DPLS), were employed to classify sugar beet samples into two groups: genetically modified organisms (GMOs) and non-GMOs. The DPLS method yielded the best classification result, and the percentages of successful classification for GM and non-GM sugar beets were both 100%. Results of the present study demonstrate the usefulness of THz spectroscopy together with chemometrics methods as a powerful tool to distinguish GM and non-GM sugar beets.

  15. Discrimination of genetically modified sugar beets based on terahertz spectroscopy.

    PubMed

    Chen, Tao; Li, Zhi; Yin, Xianhua; Hu, Fangrong; Hu, Cong

    2016-01-15

    The objective of this paper was to apply terahertz (THz) spectroscopy combined with chemometrics techniques for discrimination of genetically modified (GM) and non-GM sugar beets. In this paper, the THz spectra of 84 sugar beet samples (36 GM sugar beets and 48 non-GM ones) were obtained by using terahertz time-domain spectroscopy (THz-TDS) system in the frequency range from 0.2 to 1.2 THz. Three chemometrics methods, principal component analysis (PCA), discriminant analysis (DA) and discriminant partial least squares (DPLS), were employed to classify sugar beet samples into two groups: genetically modified organisms (GMOs) and non-GMOs. The DPLS method yielded the best classification result, and the percentages of successful classification for GM and non-GM sugar beets were both 100%. Results of the present study demonstrate the usefulness of THz spectroscopy together with chemometrics methods as a powerful tool to distinguish GM and non-GM sugar beets. PMID:26436847

  16. Genetic interactions and modifier genes in Hirschsprung's disease

    PubMed Central

    Wallace, Adam S; Anderson, Richard B

    2011-01-01

    Hirschsprung’s disease is a congenital disorder that occurs in 1:5000 live births. It is characterised by an absence of enteric neurons along a variable region of the gastrointestinal tract. Hirschsprung’s disease is classified as a multigenic disorder, because the same phenotype is associated with mutations in multiple distinct genes. Furthermore, the genetics of Hirschsprung’s disease are highly complex and not strictly Mendelian. The phenotypic variability and incomplete penetrance observed in Hirschsprung’s disease also suggests the involvement of modifier genes. Here, we summarise the current knowledge of the genetics underlying Hirschsprung’s disease based on human and animal studies, focusing on the principal causative genes, their interactions, and the role of modifier genes. PMID:22174542

  17. THE MAIZE UNSTABLE FACTOR FOR ORANGE1 IS A DOMINANT EPIGENETIC MODIFIER OF A TISSUE SPECIFICALLY SILENT ALLELE OF PERICARP COLOR1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have characterized Ufo1 (unstable factor for orange1), a dominant, allele-specific modifier of expression of the maize pericarp color1 (p1) gene. The p1 gene encodes a Myb-homologous transcriptional activator of genes required for biosynthesis of red phlobaphene pigments. The P1-wr allele speci...

  18. Genetic analysis and molecular mapping of maize (Zea mays L.) stalk rot resistant gene Rfg1.

    PubMed

    Yang, D E; Zhang, C L; Zhang, D S; Jin, D M; Weng, M L; Chen, S J; Nguyen, H; Wang, B

    2004-02-01

    One single pathogen Fusarium graminearum Schw. was inoculated to maize inbred lines 1,145 (Resistant) and Y331 (Susceptive), and their progenies of F(1), F(2) and BC(1)F(1) populations. Field statistical data revealed that all of the F(1) individuals were resistant to the disease and that the ratio of resistant plants to susceptive plants was 3:1 in the F(2) population, and 1:1 in the BC(1)F(1 )population. The results revealed that a single dominant gene controls the resistance to F. graminearum Schw. The resistant gene to F. graminearum Schw. was denominated as Rfg1 according to the standard principle of the nomenclature of the plant disease resistant genes. RAPD (randomly amplified polymorphic DNA) combined with BSA (bulked segregant analysis) analysis was carried out in the developed F(2) and BC(1)F(1 )populations, respectively. Three RAPD products screened from the RAPD analysis with 820 Operon 10-mer primers showed the linkage relation with the resistant gene Rfg1. The three RAPD amplification products (OPD-20(1000), OPA-04(1100) and OPY-04(900)) were cloned and their copy numbers were determined. The results indicated that only OPY-04(900) was a single-copy sequence. Then, OPY-04(900) was used as a probe to map the Rfg1 gene with a RIL F(7) mapping population provided by Henry Nguyen, which was developed from the cross "S3xMo17". Rfg1 was primarily mapped on chromosome 6 between the two linked markers OPY-04(900) and umc21 (Bin 6.04-6.05). In order to confirm the primary mapping result, 25 SSR (simple sequence repeat) markers and six RFLP (restriction fragment length polymorphism) markers in the Rfg1 gene-encompassing region were selected, and their linkage relation with Rfg1 was analyzed in our F(2) population. Results indicated that SSR marker mmc0241 and RFLP marker bnl3.03 are flanking the Rfg1 gene with a genetic distance of 3.0 cM and 2.0 cM, respectively. This is the first time to name and to map a single resistant gene of maize stalk rot through a single pathogen inoculation and molecular marker analysis. PMID:14647897

  19. Manufacturing genetically modified T cells for clinical trials.

    PubMed

    Gee, A P

    2015-03-01

    Compliance with Food and Drug Administration regulations relating to initiating early phase clinical trials of new cellular therapy products often presents a hurdle to new investigators. One of the biggest obstacles is the requirement to manufacture the therapeutic products under current Good Manufacturing Practices-a system that is usually poorly understood by both basic researchers and clinicians. This article reviews the major points that must be addressed when manufacturing genetically modified T cells for therapeutic use. PMID:25633481

  20. Genetic and Quantitative Trait Locus Analysis for Bio-Oil Compounds after Fast Pyrolysis in Maize Cobs.

    PubMed

    Jeffrey, Brandon; Kuzhiyil, Najeeb; de Leon, Natalia; Lübberstedt, Thomas

    2016-01-01

    Fast pyrolysis has been identified as one of the biorenewable conversion platforms that could be a part of an alternative energy future, but it has not yet received the same attention as cellulosic ethanol in the analysis of genetic inheritance within potential feedstocks such as maize. Ten bio-oil compounds were measured via pyrolysis/gas chromatography-mass spectrometry (Py/GC-MS) in maize cobs. 184 recombinant inbred lines (RILs) of the intermated B73 x Mo17 (IBM) Syn4 population were analyzed in two environments, using 1339 markers, for quantitative trait locus (QTL) mapping. QTL mapping was performed using composite interval mapping with significance thresholds established by 1000 permutations at α = 0.05. 50 QTL were found in total across those ten traits with R2 values ranging from 1.7 to 5.8%, indicating a complex quantitative inheritance of these traits. PMID:26745365

  1. Genetic and Quantitative Trait Locus Analysis for Bio-Oil Compounds after Fast Pyrolysis in Maize Cobs

    PubMed Central

    Jeffrey, Brandon; Kuzhiyil, Najeeb; de Leon, Natalia; Lübberstedt, Thomas

    2016-01-01

    Fast pyrolysis has been identified as one of the biorenewable conversion platforms that could be a part of an alternative energy future, but it has not yet received the same attention as cellulosic ethanol in the analysis of genetic inheritance within potential feedstocks such as maize. Ten bio-oil compounds were measured via pyrolysis/gas chromatography-mass spectrometry (Py/GC-MS) in maize cobs. 184 recombinant inbred lines (RILs) of the intermated B73 x Mo17 (IBM) Syn4 population were analyzed in two environments, using 1339 markers, for quantitative trait locus (QTL) mapping. QTL mapping was performed using composite interval mapping with significance thresholds established by 1000 permutations at α = 0.05. 50 QTL were found in total across those ten traits with R2 values ranging from 1.7 to 5.8%, indicating a complex quantitative inheritance of these traits. PMID:26745365

  2. Molecular genetics of the R complex of maize. Final technical report DE-FG02-86ER13627

    SciTech Connect

    Dellaporta, Stephen

    2000-10-01

    A molecular genetic characterization of the maize R-r complex of maize was completed during the period of support. The complex was shown to consist of two main regions: the P region, containing the r-p gene which controlled pigmentation of plant parts, and the S subcomplex, containing two rl-s genes in head-to-head orientation and a nonfunctional component termed rl-q. By examining the DNA sequences at the junction of the rl genes, the complex was shown to be derived by a series of abortive transposition events. The transposable element involved in the gene duplication and rearrangements was characterized and called doppia. Meiotic instability of the R-r complex was also characterized. Loss of P or S function was associated with several structural changes including intrachromosomal recombination and excision of a novel transposable element that appears to show instability only during meiosis.

  3. Genetically modified T cells in cancer therapy: opportunities and challenges

    PubMed Central

    Sharpe, Michaela; Mount, Natalie

    2015-01-01

    Tumours use many strategies to evade the host immune response, including downregulation or weak immunogenicity of target antigens and creation of an immune-suppressive tumour environment. T cells play a key role in cell-mediated immunity and, recently, strategies to genetically modify T cells either through altering the specificity of the T cell receptor (TCR) or through introducing antibody-like recognition in chimeric antigen receptors (CARs) have made substantial advances. The potential of these approaches has been demonstrated in particular by the successful use of genetically modified T cells to treat B cell haematological malignancies in clinical trials. This clinical success is reflected in the growing number of strategic partnerships in this area that have attracted a high level of investment and involve large pharmaceutical organisations. Although our understanding of the factors that influence the safety and efficacy of these therapies has increased, challenges for bringing genetically modified T-cell immunotherapy to many patients with different tumour types remain. These challenges range from the selection of antigen targets and dealing with regulatory and safety issues to successfully navigating the routes to commercial development. However, the encouraging clinical data, the progress in the scientific understanding of tumour immunology and the improvements in the manufacture of cell products are all advancing the clinical translation of these important cellular immunotherapies. PMID:26035842

  4. Genetically modified T cells in cancer therapy: opportunities and challenges.

    PubMed

    Sharpe, Michaela; Mount, Natalie

    2015-04-01

    Tumours use many strategies to evade the host immune response, including downregulation or weak immunogenicity of target antigens and creation of an immune-suppressive tumour environment. T cells play a key role in cell-mediated immunity and, recently, strategies to genetically modify T cells either through altering the specificity of the T cell receptor (TCR) or through introducing antibody-like recognition in chimeric antigen receptors (CARs) have made substantial advances. The potential of these approaches has been demonstrated in particular by the successful use of genetically modified T cells to treat B cell haematological malignancies in clinical trials. This clinical success is reflected in the growing number of strategic partnerships in this area that have attracted a high level of investment and involve large pharmaceutical organisations. Although our understanding of the factors that influence the safety and efficacy of these therapies has increased, challenges for bringing genetically modified T-cell immunotherapy to many patients with different tumour types remain. These challenges range from the selection of antigen targets and dealing with regulatory and safety issues to successfully navigating the routes to commercial development. However, the encouraging clinical data, the progress in the scientific understanding of tumour immunology and the improvements in the manufacture of cell products are all advancing the clinical translation of these important cellular immunotherapies. PMID:26035842

  5. Controversy over genetically modified organisms: the governing laws and regulations.

    PubMed

    Keatley, K L

    2000-01-01

    Genetically Modified Organisms (GMOs) are increasingly becoming a topic of controversy in the U.S. and abroad. The public is questioning their safety and wanting the products labeled as genetically modified. There are other concerns from some of the scientific world and some government officials and organizations such as the Food & Agricultural Organization (FAO) that question whether adequate research has been done to qualify GMOs as safe for long-term use. Of particular concern are the allergenic properties, a GMO may impart, possible transfer effects of antibiotic resistance (given that antibiotic resistant marker genes are used for many GMOs), the expression of previously unexpressed traits, and the drift of pollen from genetically modified crops. It has also been noted that the laws and regulations governing the biotechnology world are outdated, are not comprehensive, and span too many agencies. The primary agencies currently regulating biotechnology are the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA). PMID:11710306

  6. Irradiation influence on the detection of genetic-modified soybeans

    NASA Astrophysics Data System (ADS)

    Villavicencio, A. L. C. H.; Araújo, M. M.; Baldasso, J. G.; Aquino, S.; Konietzny, U.; Greiner, R.

    2004-09-01

    Three soybean varieties were analyzed to evaluate the irradiation influence on the detection of genetic modification. Samples were treated in a 60Co facility at dose levels of 0, 500, 800, and 1000Gy. The seeds were at first analyzed by Comet Assay as a rapid screening irradiation detection method. Secondly, germination test was performed to detect the viability of irradiated soybeans. Finally, because of its high sensitivity, its specificity and rapidity the polimerase chain reaction was the method applied for genetic modified organism detection. The analysis of DNA by the single technique of microgel electrophoresis of single cells (DNA Comet Assay) showed that DNA damage increased with increasing radiation doses. No negative influence of irradiation on the genetic modification detection was found.

  7. Biocontainment of genetically modified organisms by synthetic protein design.

    PubMed

    Mandell, Daniel J; Lajoie, Marc J; Mee, Michael T; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E; Gregg, Christopher J; Stoddard, Barry L; Church, George M

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites. PMID:25607366

  8. Biocontainment of genetically modified organisms by synthetic protein design

    NASA Astrophysics Data System (ADS)

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

  9. The Detection of Genetically Modified Organisms: An Overview

    NASA Astrophysics Data System (ADS)

    Ovesná, Jaroslava; Demnerová, Kateřina; Pouchová, Vladimíra

    Genetically modified organisms (GMOs) are those whose genetic material has been altered by the insertion of a new gene or by the deletion of an existing one(s). Modern biotechnology, in particular, the rise of genetic engineering, has supported the development of GMOs suitable for research purposes and practical applications (Gepts, 2002; Novoselova,Meuwissen, & Huirne, 2007; Sakakibara & Saito, 2006). For over 20 years GM bacteria and other GM organisms have been used in laboratories for the study of gene functions (Maliga & Small, 2007; Ratledge & Kristiansen, 2006). Agricultural plants were the first GMOs to be released into the environment and placed on the market. Farmers around the world use GMsoybeans, GMcorn and GM cotton that are herbicide tolerant, or insect resistant, or combine several traits that reduce the costs associated with crop production (Corinne, Fernandez-Cornejo, & Goodhue, 2004).

  10. Biocontainment of genetically modified organisms by synthetic protein design

    PubMed Central

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-01-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient either because they impose evolutionary pressure on the organism to eject the safeguard, because they can be circumvented by environmentally available compounds, or because they can be overcome by horizontal gene transfer (HGT). Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code to confer metabolic dependence on nonstandard amino acids for survival. The resulting GMOs cannot metabolically circumvent their biocontainment mechanisms using environmentally available compounds, and they exhibit unprecedented resistance to evolutionary escape via mutagenesis and HGT. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by reliance on synthetic metabolites. PMID:25607366

  11. The Case of the "Tainted" Taco Shells: A Case Study on Genetically Modified Foods

    ERIC Educational Resources Information Center

    Taylor, Ann T. S.

    2004-01-01

    This case study introduces students to the use of genetically modified foods. Students learn how genetically modified plants are made, and then they read primary literature papers to evaluate the environmental, economic, and health issues. (Contains 2 figures.)

  12. Genetic and Molecular Characterization of Submergence Response Identifies Subtol6 as a Major Submergence Tolerance Locus in Maize

    PubMed Central

    Campbell, Malachy T.; Proctor, Christopher A.; Dou, Yongchao; Schmitz, Aaron J.; Phansak, Piyaporn; Kruger, Greg R.; Zhang, Chi; Walia, Harkamal

    2015-01-01

    Maize is highly sensitive to short term flooding and submergence. Early season flooding reduces germination, survival and growth rate of maize seedlings. We aimed to discover genetic variation for submergence tolerance in maize and elucidate the genetic basis of submergence tolerance through transcriptional profiling and linkage analysis of contrasting genotypes. A diverse set of maize nested association mapping (NAM) founder lines were screened, and two highly tolerant (Mo18W and M162W) and sensitive (B97 and B73) genotypes were identified. Tolerant lines exhibited delayed senescence and lower oxidative stress levels compared to sensitive lines. Transcriptome analysis was performed on these inbreds to provide genome level insights into the molecular responses to submergence. Tolerant lines had higher transcript abundance of several fermentation-related genes and an unannotated Pyrophosphate-Dependent Fructose-6-Phosphate 1-Phosphotransferase gene during submergence. A coexpression network enriched for CBF (C-REPEAT/DRE BINDING FACTOR: C-REPEAT/DRE BINDING FACTOR) genes, was induced by submergence in all four inbreds, but was more activated in the tolerant Mo18W. A recombinant inbred line (RIL) population derived from Mo18W and B73 was screened for submergence tolerance. A major QTL named Subtol6 was mapped to chromosome 6 that explains 22% of the phenotypic variation within the RIL population. We identified two candidate genes (HEMOGLOBIN2 and RAV1) underlying Subtol6 based on contrasting expression patterns observed in B73 and Mo18W. Sources of tolerance identified in this study (Subtol6) can be useful to increase survival rate during flooding events that are predicted to increase in frequency with climate change. PMID:25806518

  13. Genetic and molecular characterization of submergence response identifies Subtol6 as a major submergence tolerance locus in maize.

    PubMed

    Campbell, Malachy T; Proctor, Christopher A; Dou, Yongchao; Schmitz, Aaron J; Phansak, Piyaporn; Kruger, Greg R; Zhang, Chi; Walia, Harkamal

    2015-01-01

    Maize is highly sensitive to short term flooding and submergence. Early season flooding reduces germination, survival and growth rate of maize seedlings. We aimed to discover genetic variation for submergence tolerance in maize and elucidate the genetic basis of submergence tolerance through transcriptional profiling and linkage analysis of contrasting genotypes. A diverse set of maize nested association mapping (NAM) founder lines were screened, and two highly tolerant (Mo18W and M162W) and sensitive (B97 and B73) genotypes were identified. Tolerant lines exhibited delayed senescence and lower oxidative stress levels compared to sensitive lines. Transcriptome analysis was performed on these inbreds to provide genome level insights into the molecular responses to submergence. Tolerant lines had higher transcript abundance of several fermentation-related genes and an unannotated Pyrophosphate-Dependent Fructose-6-Phosphate 1-Phosphotransferase gene during submergence. A coexpression network enriched for CBF (C-REPEAT/DRE BINDING FACTOR: C-REPEAT/DRE BINDING FACTOR) genes, was induced by submergence in all four inbreds, but was more activated in the tolerant Mo18W. A recombinant inbred line (RIL) population derived from Mo18W and B73 was screened for submergence tolerance. A major QTL named Subtol6 was mapped to chromosome 6 that explains 22% of the phenotypic variation within the RIL population. We identified two candidate genes (HEMOGLOBIN2 and RAV1) underlying Subtol6 based on contrasting expression patterns observed in B73 and Mo18W. Sources of tolerance identified in this study (Subtol6) can be useful to increase survival rate during flooding events that are predicted to increase in frequency with climate change. PMID:25806518

  14. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    DOEpatents

    Rajgarhia, Vineet [Kingsport, TN; Koivuranta, Kari [Helsinki, FI; Penttila, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Maple Grove, MN; Miller, Christopher Kenneth [Cottage Grove, MN; Olson, Stacey [St. Bonifacius, MN; Ruohonen, Laura [Helsinki, FI

    2014-01-07

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  15. Genetically modified yeast species, and fermentation processes using genetically modified yeast

    DOEpatents

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2013-05-14

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  16. Genetically modified yeast species and fermentation processes using genetically modified yeast

    DOEpatents

    Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

    2011-05-17

    Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications', include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

  17. Maize Centromeres: Organization and Functional Adaptation in the Genetic Background of Oat

    PubMed Central

    Jin, Weiwei; Melo, Juliana R.; Nagaki, Kiyotaka; Talbert, Paul B.; Henikoff, Steven; Dawe, R. Kelly; Jiang, Jiming

    2004-01-01

    Centromeric DNA sequences in multicellular eukaryotes are often highly repetitive and are not unique to a specific centromere or to centromeres at all. Thus, it is a major challenge to study the fine structure of individual plant centromeres. We used a DNA fiber-fluorescence in situ hybridization approach to study individual maize (Zea mays) centromeres using oat (Avena sativa)-maize chromosome addition lines. The maize centromere-specific satellite repeat CentC in the addition lines allowed us to delineate the size and organization of centromeric DNA of individual maize chromosomes. We demonstrate that the cores of maize centromeres contain mainly CentC arrays and clusters of a centromere-specific retrotransposon, CRM. CentC and CRM sequences are highly intermingled. The amount of CentC/CRM sequence varies from ?300 to >2800 kb among different centromeres. The association of CentC and CRM with centromeric histone H3 (CENH3) was visualized by a sequential detection procedure on stretched centromeres. The analysis revealed that CENH3 is always associated with CentC and CRM but that not all CentC or CRM sequences are associated with CENH3. We further demonstrate that in the chromosomal addition lines in which two CenH3 genes were present, one from oat and one from maize, the oat CENH3 was consistently incorporated by the maize centromeres. PMID:14973167

  18. One simple DNA extraction device and its combination with modified visual loop-mediated isothermal amplification for rapid on-field detection of genetically modified organisms.

    PubMed

    Zhang, Miao; Liu, Yinan; Chen, Lili; Quan, Sheng; Jiang, Shimeng; Zhang, Dabing; Yang, Litao

    2013-01-01

    Quickness, simplicity, and effectiveness are the three major criteria for establishing a good molecular diagnosis method in many fields. Herein we report a novel detection system for genetically modified organisms (GMOs), which can be utilized to perform both on-field quick screening and routine laboratory diagnosis. In this system, a newly designed inexpensive DNA extraction device was used in combination with a modified visual loop-mediated isothermal amplification (vLAMP) assay. The main parts of the DNA extraction device included a silica gel membrane filtration column and a modified syringe. The DNA extraction device could be easily operated without using other laboratory instruments, making it applicable to an on-field GMO test. High-quality genomic DNA (gDNA) suitable for polymerase chain reaction (PCR) and isothermal amplification could be quickly isolated from plant tissues using this device within 15 min. In the modified vLAMP assay, a microcrystalline wax encapsulated detection bead containing SYBR green fluorescent dye was introduced to avoid dye inhibition and cross-contaminations from post-LAMP operation. The system was successfully applied and validated in screening and identification of GM rice, soybean, and maize samples collected from both field testing and the Grain Inspection, Packers, and Stockyards Administration (GIPSA) proficiency test program, which demonstrated that it was well-adapted to both on-field testing and/or routine laboratory analysis of GMOs. PMID:23181490

  19. Spatiotemporal patterns of non-genetically modified crops in the era of expansion of genetically modified food.

    PubMed

    Sun, Jing; Wu, Wenbin; Tang, Huajun; Liu, Jianguo

    2015-01-01

    Despite heated debates over the safety of genetically modified (GM) food, GM crops have been expanding rapidly. Much research has focused on the expansion of GM crops. However, the spatiotemporal dynamics of non-genetically modified (non-GM) crops are not clear, although they may have significant environmental and agronomic impacts and important policy implications. To understand the dynamics of non-GM crops and to inform the debates among relevant stakeholders, we conducted spatiotemporal analyses of China's major non-GM soybean production region, the Heilongjiang Province. Even though the total soybean planting area decreased from 2005 to 2010, surprisingly, there were hotspots of increase. The results also showed hotspots of loss as well as a large decline in the number and continuity of soybean plots. Since China is the largest non-GM soybean producer in the world, the decline of its major production region may signal the continual decline of global non-GM soybeans. PMID:26380899

  20. Spatiotemporal patterns of non-genetically modified crops in the era of expansion of genetically modified food

    PubMed Central

    Sun, Jing; Wu, Wenbin; Tang, Huajun; Liu, Jianguo

    2015-01-01

    Despite heated debates over the safety of genetically modified (GM) food, GM crops have been expanding rapidly. Much research has focused on the expansion of GM crops. However, the spatiotemporal dynamics of non-genetically modified (non-GM) crops are not clear, although they may have significant environmental and agronomic impacts and important policy implications. To understand the dynamics of non-GM crops and to inform the debates among relevant stakeholders, we conducted spatiotemporal analyses of China’s major non-GM soybean production region, the Heilongjiang Province. Even though the total soybean planting area decreased from 2005 to 2010, surprisingly, there were hotspots of increase. The results also showed hotspots of loss as well as a large decline in the number and continuity of soybean plots. Since China is the largest non-GM soybean producer in the world, the decline of its major production region may signal the continual decline of global non-GM soybeans. PMID:26380899

  1. Selection of focal earthworm species as non-target soil organisms for environmental risk assessment of genetically modified plants.

    PubMed

    van Capelle, Christine; Schrader, Stefan; Arpaia, Salvatore

    2016-04-01

    By means of a literature survey, earthworm species of significant relevance for soil functions in different biogeographical regions of Europe (Atlantic, Boreal, Mediterranean) were identified. These focal earthworm species, defined here according to the EFSA Guidance Document on the environmental risk assessment (ERA) of genetically modified plants, are typical for arable soils under crop rotations with maize and/or potatoes within the three regions represented by Ireland, Sweden and Spain, respectively. Focal earthworm species were selected following a matrix of four steps: Identification of functional groups, categorization of non-target species, ranking species on ecological criteria, and final selection of focal species. They are recommended as appropriate non-target organisms to assess environmental risks of genetically modified (GM) crops; in this case maize and potatoes. In total, 44 literature sources on earthworms in arable cropping systems including maize or potato from Ireland, Sweden and Spain were collected, which present information on species diversity, individual density and specific relevance for soil functions. By means of condensed literature data, those species were identified which (i) play an important functional role in respective soil systems, (ii) are well adapted to the biogeographical regions, (iii) are expected to occur in high abundances under cultivation of maize or potato and (iv) fulfill the requirements for an ERA test system based on life-history traits. First, primary and secondary decomposers were identified as functional groups being exposed to the GM crops. In a second step, anecic and endogeic species were categorized as potential species. In step three, eight anecic and endogeic earthworm species belonging to the family Lumbricidae were ranked as relevant species: Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea longa, Allolobophora chlorotica, Lumbricus terrestris, Lumbricus friendi, Octodrilus complanatus and Octolasion cyaneum. Five out of these eight species are relevant for each biogeographical region with an overlap in the species. Finally, the earthworm species Ap. caliginosa (endogeic, secondary decomposer) and L. terrestris (anecic, primary decomposer) were selected as focal species. In the Mediterranean region L. terrestris may be substituted by the more relevant anecic species L. friendi. The selected focal species are recommended to be included in a standardized laboratory ERA test system based on life-history traits. PMID:26803734

  2. MaizeCyc: Metabolic networks in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

  3. Animal nutrition with feeds from genetically modified plants.

    PubMed

    Flachowsky, Gerhard; Chesson, Andrew; Aulrich, Karen

    2005-02-01

    Plant breeders have made and will continue to make important contributions toward meeting the need for more and better feed and food. The use of new techniques to modify the genetic makeup of plants to improve their properties has led to a new generation of crops, grains and their by-products for feed. The use of ingredients and products from genetically modified plants (GMP) in animal nutrition properly raises many questions and issues, such as the role of a nutritional assessment of the modified feed or feed additive as part of safety assessment, the possible influence of genetically modified (GM) products on animal health and product quality and the persistence of the recombinant DNA and of the 'novel' protein in the digestive tract and tissues of food-producing animals. During the last few years many studies have determined the nutrient value of GM feeds compared to their conventional counterparts and some have additionally followed the fate of DNA and novel protein. The results available to date are reassuring and reveal no significant differences in the safety and nutritional value of feedstuffs containing material derived from the so-called 1st generation of genetically modified plants (those with unchanged gross composition) in comparison with non-GM varieties. In addition, no residues of recombinant DNA or novel proteins have been found in any organ or tissue samples obtained from animals fed with GMP. These results indicate that for compositionally equivalent GMP routine-feeding studies with target species generally add little to nutritional and safety assessment. However, the strategies devised for the nutritional and safety assessment of the 1st generation products will be much more difficult to apply to 2nd generation GMP in which significant changes in constituents have been deliberately introduced (e.g., increased fatty acids or amino acids content or a reduced concentration of undesirable constituents). It is suggested that studies made with animals will play a much more important role in insuring the safety of these 2nd generation constructs. PMID:15889650

  4. Genetically Modified T-Cell Therapy for Osteosarcoma

    PubMed Central

    DeRenzo, Christopher

    2015-01-01

    T-cell immunotherapy may offer an approach to improve outcomes for patients with osteosarcoma, who fail current therapies. In addition, it has the potential to reduce treatment-related complications for all patients. Generating tumor-specific T cells with conventional antigen presenting cells ex vivo is time consuming and often results in T-cell products with a low frequency of tumor-specific T cells. In addition, the generated T cells remain sensitive to the immunosuppressive tumor microenvironment. Genetic modification of T cells is one strategy to overcome these limitations. For example, T cells can be genetically modified to render them antigen specific, resistant to inhibitory factors, or increase their ability to home to tumor sites. Most genetic modification strategies have only been evaluated in preclinical models, however early phase clinical trials are in progress. In this chapter we review the current status of gene-modified T-cell therapy with special focus on osteosarcoma, highlighting potential antigenic targets, preclinical and clinical studies, and strategies to improve current T-cell therapy approaches. PMID:24924183

  5. [Genetically modified organisms: a new threat to food safety].

    TOXLINE Toxicology Bibliographic Information

    Spendeler L

    2005-03-01

    This article analyzes all of the food safety-related aspects related to the use of genetically modified organisms into agriculture and food. A discussion is provided as to the uncertainties related to the insertion of foreign genes into organisms, providing examples of unforeseen, undesirable effects and of instabilities of the organisms thus artificially fabricated. Data is then provided from both official agencies as well as existing literature questioning the accuracy and reliability of the risk analyses as to these organisms being harmless to health and discusses the almost total lack of scientific studies analyzing the health safety/dangerousness of transgenic foods. Given all these unknowns, other factors must be taken into account, particularly genetic contamination of the non-genetically modified crops, which is now starting to become widespread in some parts of the world. Not being able of reversing the situation in the even of problems is irresponsible. Other major aspects are the impacts on the environment (such as insects building up resistances, the loss of biodiversity, the increase in chemical products employed) with indirect repercussions on health and/or future food production. Lastly, thoughts for discussion are added concerning food safety in terms of food availability and food sovereignty, given that the transgenic seed and related agrochemicals market is currently cornered by five large-scale transnational companies. The conclusion entails an analysis of biotechnological agriculture's contribution to sustainability.

  6. Hypothetical link between infertility and genetically modified food.

    PubMed

    Gao, Mingxia; Li, Bin; Yuan, Wenzhen; Zhao, Lihui; Zhang, Xuehong

    2014-01-01

    It is speculated that genetically modified food (GMF)/genetically modified organism (GMO) is responsible for infertility development. The risk linked with a wide use of GMFs/GMOs offers the basic elements for social criticism. However, to date, it has not been justified whether the bad effects are directly resulted from products of genetic modifications or trans-genesis process. Extensive experience with the risk assessment of whole foods has been applied recently on the safety and nutritional testing of GMFs/GMOs. Investigations have tested the safety of GMFs including sub-acute, chronic, reproductive, multi-generation and carcinogenicity studies. We extrapolated the potential risks associated with GMFs/GMOs on reproduction, and analyzed the multi-aspect linked between infertility and GMFs/GMOs. It could be conjectured that GMFs/GMOs could be potential hazard on reproduction, linking to the development of infertility through influencing the endocrine metabolism, endometriosis. However, little evidence shows the impaction on embryo or reproductive related tumor due to the limited literatures, and needs further research. The article presents some related patents on GMFs/GMOs, and some methods for tracking GMOs. PMID:25342149

  7. [Genetically modified organisms: a new threat to food safety].

    PubMed

    Spendeler, Liliane

    2005-01-01

    This article analyzes all of the food safety-related aspects related to the use of genetically modified organisms into agriculture and food. A discussion is provided as to the uncertainties related to the insertion of foreign genes into organisms, providing examples of unforeseen, undesirable effects and of instabilities of the organisms thus artificially fabricated. Data is then provided from both official agencies as well as existing literature questioning the accuracy and reliability of the risk analyses as to these organisms being harmless to health and discusses the almost total lack of scientific studies analyzing the health safety/dangerousness of transgenic foods. Given all these unknowns, other factors must be taken into account, particularly genetic contamination of the non-genetically modified crops, which is now starting to become widespread in some parts of the world. Not being able of reversing the situation in the even of problems is irresponsible. Other major aspects are the impacts on the environment (such as insects building up resistances, the loss of biodiversity, the increase in chemical products employed) with indirect repercussions on health and/or future food production. Lastly, thoughts for discussion are added concerning food safety in terms of food availability and food sovereignty, given that the transgenic seed and related agrochemicals market is currently cornered by five large-scale transnational companies. The conclusion entails an analysis of biotechnological agriculture's contribution to sustainability. PMID:15913060

  8. A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis

    PubMed Central

    Li, Pengcheng; Chen, Fanjun; Cai, Hongguang; Liu, Jianchao; Pan, Qingchun; Liu, Zhigang; Gu, Riliang; Mi, Guohua; Zhang, Fusuo; Yuan, Lixing

    2015-01-01

    That root system architecture (RSA) has an essential role in nitrogen acquisition is expected in maize, but the genetic relationship between RSA and nitrogen use efficiency (NUE) traits remains to be elucidated. Here, the genetic basis of RSA and NUE traits was investigated in maize using a recombination inbred line population that was derived from two lines contrasted for both traits. Under high-nitrogen and low-nitrogen conditions, 10 NUE- and 9 RSA-related traits were evaluated in four field environments and three hydroponic experiments, respectively. In contrast to nitrogen utilization efficiency (NutE), nitrogen uptake efficiency (NupE) had significant phenotypic correlations with RSA, particularly the traits of seminal roots (r = 0.15–0.31) and crown roots (r = 0.15–0.18). A total of 331 quantitative trait loci (QTLs) were detected, including 184 and 147 QTLs for NUE- and RSA-related traits, respectively. These QTLs were assigned into 64 distinct QTL clusters, and ~70% of QTLs for nitrogen-efficiency (NUE, NupE, and NutE) coincided in clusters with those for RSA. Five important QTLs clusters at the chromosomal regions bin1.04, 2.04, 3.04, 3.05/3.06, and 6.07/6.08 were found in which QTLs for both traits had favourable effects from alleles coming from the large-rooted and high-NupE parent. Introgression of these QTL clusters in the advanced backcross-derived lines conferred mean increases in grain yield of ~14.8% for the line per se and ~15.9% in the testcross. These results reveal a significant genetic relationship between RSA and NUE traits, and uncover the most promising genomic regions for marker-assisted selection of RSA to improve NUE in maize. PMID:25873660

  9. A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis.

    PubMed

    Li, Pengcheng; Chen, Fanjun; Cai, Hongguang; Liu, Jianchao; Pan, Qingchun; Liu, Zhigang; Gu, Riliang; Mi, Guohua; Zhang, Fusuo; Yuan, Lixing

    2015-06-01

    That root system architecture (RSA) has an essential role in nitrogen acquisition is expected in maize, but the genetic relationship between RSA and nitrogen use efficiency (NUE) traits remains to be elucidated. Here, the genetic basis of RSA and NUE traits was investigated in maize using a recombination inbred line population that was derived from two lines contrasted for both traits. Under high-nitrogen and low-nitrogen conditions, 10 NUE- and 9 RSA-related traits were evaluated in four field environments and three hydroponic experiments, respectively. In contrast to nitrogen utilization efficiency (NutE), nitrogen uptake efficiency (NupE) had significant phenotypic correlations with RSA, particularly the traits of seminal roots (r = 0.15-0.31) and crown roots (r = 0.15-0.18). A total of 331 quantitative trait loci (QTLs) were detected, including 184 and 147 QTLs for NUE- and RSA-related traits, respectively. These QTLs were assigned into 64 distinct QTL clusters, and ~70% of QTLs for nitrogen-efficiency (NUE, NupE, and NutE) coincided in clusters with those for RSA. Five important QTLs clusters at the chromosomal regions bin1.04, 2.04, 3.04, 3.05/3.06, and 6.07/6.08 were found in which QTLs for both traits had favourable effects from alleles coming from the large-rooted and high-NupE parent. Introgression of these QTL clusters in the advanced backcross-derived lines conferred mean increases in grain yield of ~14.8% for the line per se and ~15.9% in the testcross. These results reveal a significant genetic relationship between RSA and NUE traits, and uncover the most promising genomic regions for marker-assisted selection of RSA to improve NUE in maize. PMID:25873660

  10. Genetic basis and detection of unintended effects in genetically modified crop plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled “Genetic Basis of Unintended Effects in Modified Plants” was held in Ottawa, Canada, bringing together over 75 s...

  11. Ionic liquids as novel solvents for biosynthesis of octenyl succinic anhydride-modified waxy maize starch.

    PubMed

    Li, Dandan; Zhang, Xiwen; Tian, Yaoqi

    2016-05-01

    Biosynthesis of octenyl succinic anhydride (OSA) starch was investigated using ionic liquids (ILs) as reaction media. Waxy maize starch was pretreated in 1-butyl-3-methylimidazolium chlorine and then esterified with OSA in 1-octyl-3-methylimidazolium nitrate by using Novozyme 435as catalyst. The degree of substitution of OSA starch reached 0.0130 with 5wt% starch concentration and 1wt% lipase dosage based on ILs weight at 50°C for 3h. The formation of OSA starch was confirmed by fourier transform infrared spectroscopy. Scanning electron microscopy and X-ray diffraction revealed that the morphology and crystal structure of starch were significantly destroyed. Thermogravimetric analysis showed that esterification decreased the thermal stability of starch. The successful lipase-catalyzed synthesis of OSA starch in ILs suggests that ILs are potential replacement of traditional organic solvents for starch ester biosynthesis. PMID:26797225

  12. The Genetic Basis of Haploid Induction in Maize Identified with a Novel Genome-Wide Association Method.

    PubMed

    Hu, Haixiao; Schrag, Tobias A; Peis, Regina; Unterseer, Sandra; Schipprack, Wolfgang; Chen, Shaojiang; Lai, Jinsheng; Yan, Jianbing; Prasanna, Boddupalli M; Nair, Sudha K; Chaikam, Vijay; Rotarenco, Valeriu; Shatskaya, Olga A; Zavalishina, Alexandra; Scholten, Stefan; Schön, Chris-Carolin; Melchinger, Albrecht E

    2016-04-01

    In vivohaploid induction (HI) triggered by pollination with special intraspecific genotypes, called inducers, is unique toZea maysL. within the plant kingdom and has revolutionized maize breeding during the last decade. However, the molecular mechanisms underlying HI in maize are still unclear. To investigate the genetic basis of HI, we developed a new approach for genome-wide association studies (GWAS), termed conditional haplotype extension (CHE) test that allows detection of selective sweeps even under almost perfect confounding of population structure and trait expression. Here, we applied this test to identify genomic regions required for HI expression and dissected the combined support interval (50.34 Mb) of the QTLqhir1, detected in a previous study, into two closely linked genomic segments relevant for HI expression. The first, termedqhir11(0.54 Mb), comprises an already fine-mapped region but was not diagnostic for differentiating inducers and noninducers. The second segment, termedqhir12(3.97 Mb), had a haplotype allele common to all 53 inducer lines but not found in any of the 1482 noninducers. By comparing resequencing data of one inducer with 14 noninducers, we detected in theqhir12region three candidate genes involved in DNA or amino acid binding, however, none forqhir11 We propose that the CHE test can be utilized in introgression breeding and different fields of genetics to detect selective sweeps in heterogeneous genetic backgrounds. PMID:26896330

  13. A Meta-Analysis of the Impacts of Genetically Modified Crops

    PubMed Central

    Klümper, Wilhelm; Qaim, Matin

    2014-01-01

    Background Despite the rapid adoption of genetically modified (GM) crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion. Objective We carry out a meta-analysis of the agronomic and economic impacts of GM crops to consolidate the evidence. Data Sources Original studies for inclusion were identified through keyword searches in ISI Web of Knowledge, Google Scholar, EconLit, and AgEcon Search. Study Eligibility Criteria Studies were included when they build on primary data from farm surveys or field trials anywhere in the world, and when they report impacts of GM soybean, maize, or cotton on crop yields, pesticide use, and/or farmer profits. In total, 147 original studies were included. Synthesis Methods Analysis of mean impacts and meta-regressions to examine factors that influence outcomes. Results On average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries. Limitations Several of the original studies did not report sample sizes and measures of variance. Conclusion The meta-analysis reveals robust evidence of GM crop benefits for farmers in developed and developing countries. Such evidence may help to gradually increase public trust in this technology. PMID:25365303

  14. Multitarget real-time PCR-based system: monitoring for unauthorized genetically modified events in India.

    PubMed

    Randhawa, Gurinder Jit; Singh, Monika; Sood, Payal; Bhoge, Rajesh K

    2014-07-23

    A multitarget TaqMan real-time PCR (RTi-PCR) based system was developed to monitor unauthorized genetically modified (GM) events in India. Most of the GM events included in this study are either authorized for commercial cultivation or field trials, which were indigenously developed or imported for research purposes. The developed system consists of a 96-well prespotted plate with lyophilized primers and probes, for simultaneous detection of 47 targets in duplicate, including 21 event-specific sequences, 5 construct regions, 15 for transgenic elements, and 6 taxon-specific targets for cotton, eggplant, maize, potato, rice, and soybean. Limit of detection (LOD) of assays ranged from 0.1 to 0.01% GM content for different targets. Applicability, robustness, and practical utility of the developed system were verified with stacked GM cotton event, powdered samples of proficiency testing and two unknown test samples. This user-friendly multitarget approach can be efficiently utilized for monitoring the unauthorized GM events in an Indian context. PMID:24971889

  15. Genetic and biochemical differences in populations bred for extremes in maize grain methionine concentration

    PubMed Central

    2014-01-01

    Background Methionine is an important nutrient in animal feed and several approaches have been developed to increase methionine concentration in maize (Zea mays L.) grain. One approach is through traditional breeding using recurrent selection. Using divergent selection, genetically related populations with extreme differences in grain methionine content were produced. In order to better understand the molecular mechanisms controlling grain methionine content, we examined seed proteins, transcript levels of candidate genes, and genotypes of these populations. Results Two populations were selected for high or low methionine concentration for eight generations and 40 and 56% differences between the high and low populations in grain methionine concentration were observed. Mean values between the high and low methionine populations differed by greater than 1.5 standard deviations in some cycles of selection. Other amino acids and total protein concentration exhibited much smaller changes. In an effort to understand the molecular mechanisms that contribute to these differences, we compared transcript levels of candidate genes encoding high methionine seed storage proteins involved in sulfur assimilation or methionine biosynthesis. In combination, we also explored the genetic mechanisms at the SNP level through implementation of an association analysis. Significant differences in methionine-rich seed storage protein genes were observed in comparisons of high and low methionine populations, while transcripts of seed storage proteins lacking high levels of methionine were unchanged. Seed storage protein levels were consistent with transcript levels. Two genes involved in sulfur assimilation, Cys2 and CgS1 showed substantial differences in allele frequencies when two selected populations were compared to the starting populations. Major genes identified across cycles of selection by a high-stringency association analysis included dzs18, wx, dzs10, and zp27. Conclusions We hypothesize that transcriptional changes alter sink strength by altering the levels of methionine-rich seed storage proteins. To meet the altered need for sulfur, a cysteine-rich seed storage protein is altered while sulfur assimilation and methionine biosynthesis throughput is changed by selection for certain alleles of Cys2 and CgS1. PMID:24552611

  16. Benefits and risks associated with genetically modified food products.

    PubMed

    Kramkowska, Marta; Grzelak, Teresa; Czyżewska, Krystyna

    2013-01-01

    Scientists employing methods of genetic engineering have developed a new group of living organisms, termed 'modified organisms', which found application in, among others, medicine, the pharmaceutical industry and food distribution. The introduction of transgenic products to the food market resulted in them becoming a controversial topic, with their proponents and contestants. The presented study aims to systematize objective data on the potential benefits and risks resulting from the consumption of transgenic food. Genetic modifications of plants and animals are justified by the potential for improvement of the food situation worldwide, an increase in yield crops, an increase in the nutritional value of food, and the development of pharmaceutical preparations of proven clinical significance. In the opinions of critics, however, transgenic food may unfavourably affect the health of consumers. Therefore, particular attention was devoted to the short- and long-lasting undesirable effects, such as alimentary allergies, synthesis of toxic agents or resistance to antibiotics. Examples arguing for the justified character of genetic modifications and cases proving that their use can be dangerous are innumerable. In view of the presented facts, however, complex studies are indispensable which, in a reliable way, evaluate effects linked to the consumption of food produced with the application of genetic engineering techniques. Whether one backs up or negates transgenic products, the choice between traditional and non-conventional food remains to be decided exclusively by the consumers. PMID:24069841

  17. An analytical approach to the implementation of genetically modified crops.

    PubMed

    Borch, K; Rasmussen, B

    2000-12-01

    Public scepticism towards genetically modified (GM) crops is increasing. To address this, the risks and benefits of GM crops must be examined across scientific disciplines, and be discussed with the authorities, the agricultural industry and the consumers. In a feasibility study we have systematically analysed the challenges of the development and marketing of GM crops in Europe. A life-cycle inventory was used together with established technology foresight techniques in an interdisciplinary and empirical framework. The approach taken in this study established a dialogue between stakeholders and provided a framework for discussions about the future direction of GM crops. PMID:11102658

  18. Safety assessment of genetically modified plants with deliberately altered composition

    PubMed Central

    Halford, Nigel G; Hudson, Elizabeth; Gimson, Amy; Weightman, Richard; Shewry, Peter R; Tompkins, Steven

    2014-01-01

    The development and marketing of ‘novel’ genetically modified (GM) crops in which composition has been deliberately altered poses a challenge to the European Union (EU)'s risk assessment processes, which are based on the concept of substantial equivalence with a non-GM comparator. This article gives some examples of these novel GM crops and summarizes the conclusions of a report that was commissioned by the European Food Safety Authority on how the EU's risk assessment processes could be adapted to enable their safety to be assessed. PMID:24735114

  19. Coral red fluorescence protein as genetic modified baculovirus tracer.

    PubMed

    Jinn, Tzyy-Rong; Kao, Suey-Sheng; Tzen, Jason T C; Wu, Tzong-Yuan

    2005-09-29

    Genetic modified baculovirus (GMBV) are among the most promising alternatives to chemical insecticides. One of the deterrents to the GMBV development is the lack of simple and cost-effective methods for monitoring their efficacy and ecology in fields. Here, we demonstrate the DsRed gene from coral can serve as a convenient GMBV tracer. Insect larvae, including Trichoplusia ni, Spodoptera exigua, and Spodoptera litura, infected the GMBV containing the DsRed gene can emit red fluorescence under sun light without any prosthetic apparatus. PMID:15979186

  20. Safety assessment and detection methods of genetically modified organisms.

    PubMed

    Xu, Rong; Zheng, Zhe; Jiao, Guanglian

    2014-01-01

    Genetically modified organisms (GMOs), are gaining importance in agriculture as well as the production of food and feed. Along with the development of GMOs, health and food safety concerns have been raised. These concerns for these new GMOs make it necessary to set up strict system on food safety assessment of GMOs. The food safety assessment of GMOs, current development status of safety and precise transgenic technologies and GMOs detection have been discussed in this review. The recent patents about GMOs and their detection methods are also reviewed. This review can provide elementary introduction on how to assess and detect GMOs. PMID:25342147

  1. Safety assessment of genetically modified plants with deliberately altered composition.

    PubMed

    Halford, Nigel G; Hudson, Elizabeth; Gimson, Amy; Weightman, Richard; Shewry, Peter R; Tompkins, Steven

    2014-08-01

    The development and marketing of 'novel' genetically modified (GM) crops in which composition has been deliberately altered poses a challenge to the European Union (EU)'s risk assessment processes, which are based on the concept of substantial equivalence with a non-GM comparator. This article gives some examples of these novel GM crops and summarizes the conclusions of a report that was commissioned by the European Food Safety Authority on how the EU's risk assessment processes could be adapted to enable their safety to be assessed. PMID:24735114

  2. [The lack of information on genetically modified organisms in Brazil].

    PubMed

    Ribeiro, Isabelle Geoffroy; Marin, Victor Augustus

    2012-02-01

    This article presents a review about the labeling of products that have Genetically Modified Organisms (GMO), also called transgenic elements in their composition. It addresses the conventions, laws and regulations relating to such products currently governing the market, the adequacy of these existing standards and their acceptance by society. It also examines the importance of the cautionary principle when assessing the application of new technologies or technologies where little is known or where there is no relevant scientific knowledge about the potential risks to the environment, human health and society. PMID:22267031

  3. Dynamically optimal strategies for managing resistance to genetically modified crops.

    PubMed

    Qiao, Fangbin; Wilen, James; Rozelle, Scott

    2008-06-01

    This paper develops a dynamic model of the evolution of pest a population and pest resistance to characterize the socially optimal refuge strategy for managing a pest's resistance to genetically modified crops. Previous theoretical economic analyses of this problem focus on steady states; we also address refuge policies along the optimal path to the final equilibrium. To elaborate on our theoretical analysis of the resistance problem, we develop a simulation model calibrated to cotton (Gossypium spp.) production in China. Our results show the importance of fitness cost as a determinant of the qualitative nature of optimal refuge policies. PMID:18613595

  4. Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

    PubMed

    Truter, J; Van Hamburg, H; Van Den Berg, J

    2014-02-01

    The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance. PMID:24472209

  5. Plant potassium content modifies the effects of arbuscular mycorrhizal symbiosis on root hydraulic properties in maize plants.

    PubMed

    El-Mesbahi, Mohamed Najib; Azcón, Rosario; Ruiz-Lozano, Juan Manuel; Aroca, Ricardo

    2012-10-01

    It is well known that the arbuscular mycorrhizal (AM) symbiosis helps the host plant to overcome several abiotic stresses including drought. One of the mechanisms for this drought tolerance enhancement is the higher water uptake capacity of the mycorrhizal plants. However, the effects of the AM symbiosis on processes regulating root hydraulic properties of the host plant, such as root hydraulic conductivity and plasma membrane aquaporin gene expression, and protein abundance, are not well defined. Since it is known that K(+) status is modified by AM and that it regulates root hydraulic properties, it has been tested how plant K(+) status could modify the effects of the symbiosis on root hydraulic conductivity and plasma membrane aquaporin gene expression and protein abundance, using maize (Zea mays L.) plants and Glomus intraradices as a model. It was observed that the supply of extra K(+) increased root hydraulic conductivity only in AM plants. Also, the different pattern of plasma membrane aquaporin gene expression and protein abundance between AM and non-AM plants changed with the application of extra K(+). Thus, plant K(+) status could be one of the causes of the different observed effects of the AM symbiosis on root hydraulic properties. The present study also highlights the critical importance of AM fungal aquaporins in regulating root hydraulic properties of the host plant. PMID:22370879

  6. Maize phytoene desaturase and zeta-carotene desaturase catalyse a poly-Z desaturation pathway: implications for genetic engineering of carotenoid content among cereal crops.

    PubMed

    Matthews, Paul D; Luo, RuiBai; Wurtzel, Eleanore T

    2003-10-01

    Carotene desaturation, an essential step in the biosynthesis of coloured carotenoids, has received much attention (1) as a target of bleaching herbicide action, (2) as a determinant of geometric isomer states of carotenoids and their metabolites, and (3) as a key modulator of accumulation and structural variability of carotenoids. Having previously isolated and functionally characterized the cDNA encoding the first enzyme in maize carotene desaturation, phytoene desaturase (PDS), the isolation and functional characterization of the second desaturase, a maize endosperm cDNA (2265 bp) encoding zetacarotene (zeta-carotene) desaturase (ZDS) is reported here. Functional analysis of the concerted actions of maize PDS and ZDS ex situ showed these enzymes to mediate a poly-Z desaturation pathway to the predominate geometric isomer 7,9,7',9'-tetra-Z-lycopene (poly-Z-lycopene or prolycopene), and not the all-trans substrate required of the downstream lycopene cyclase enzymes. This finding suggests a rate-controlling isomerase associated with the carotene desaturases as a corollary of a default poly-Z carotenoid biosynthetic pathway active in planta for maize. Comparative gene analysis between maize and rice revealed that genes encoding PDS and ZDS are single copy; the Zds cDNA characterized here was mapped to maize chromosome 7S and vp9 is suggested as a candidate locus for the structural gene while y9 is ruled out. Classical genetic resources were used to dissect the desaturation steps further and hydroxyphenylpyruvate dioxygenase was linked to the vp2 locus, narrowing candidate loci for an obligate isomerase in maize to only a few. Since the first functional analysis of the paired carotene desaturases for a cereal crop is reported here, the implications for the genetic modification of the pro-vitamin A content in cereal crops such as rice and maize, are discussed. PMID:14504297

  7. Molecular genetics of the maize (Zea mays L.) aspartate kinase-homoserine dehydrogenase gene family.

    PubMed Central

    Muehlbauer, G J; Somers, D A; Matthews, B F; Gengenbach, B G

    1994-01-01

    Aspartate kinase (AK) and homoserine dehydrogenase (HSDH) are enzymes in the aspartate-derived amino acid biosynthetic pathway. Recent biochemical evidence indicates that an AK-HSDH bifunctional enzyme exists in maize (Zea mays L.). In this report, we characterize three genes that encode subunits of AK-HSDH. Two cDNAs, pAKHSDH1 and pAKHSDH2, containing the full-coding sequence, and one partial cDNA, pAKHSDH3, encode amino acid sequences similar to the reported monofunctional AK and HSDH enzymes from prokaryotes and yeast (Saccharomyces cerevisiae) and to AK-HSDH bifunctional enzymes of prokaryotes, yeast, carrot (Daucus carota), and Arabidopsis thaliana. Immunological and biochemical analyses verify that the cDNAs encode AK-HSDH and indicate that both the AK and HSDH activities are feedback inhibited by threonine. RNA blots identify a 3.2-kb transcript in all maize tissues examined. pAKHSDH1 and pAKHSDH2 map to chromosomes 4L and 2S, respectively. This study shows that maize contains AK-HSDH bifunctional enzyme(s) encoded by a small gene family of at least three genes. Maize AK-HSDH has conserved sequences found in communication modules of prokaryotic two-component regulatory systems, which has led us to propose that maize AK-HSDH may be involved in a similar regulatory mechanism. PMID:7846152

  8. Maximum hydrogen production from genetically modified microalgae biomass

    NASA Astrophysics Data System (ADS)

    Vargas, Jose; Kava, Vanessa; Ordonez, Juan

    A transient mathematical model for managing microalgae derived H2 production as a source of renewable energy is developed for a well stirred photobioreactor, PBR. The model allows for the determination of microalgae and H2 mass fractions produced by the PBR in time. A Michaelis-Menten expression is proposed for modeling the rate of H2 production, which introduces an expression to calculate the resulting effect on H2 production rate after genetically modifying the microalgae. The indirect biophotolysis process was used. Therefore, an opportunity was found to optimize the aerobic to anaerobic stages time ratio of the cycle for maximum H2 production rate, i.e., the process rhythm. A system thermodynamic optimization is conducted with the model equations to find accurately the optimal system operating rhythm for maximum H2 production rate, and how wild and genetically modified species compare to each other. The maxima found are sharp, showing up to a ~60% variation in hydrogen production rate within 2 days around the optimal rhythm, which highlights the importance of system operation in such condition. Therefore, the model is expected to be useful for design, control and optimization of H2 production. Brazilian National Council of Scientific and Technological Development, CNPq (project 482336/2012-9).

  9. Genetically modified crops: detection strategies and biosafety issues.

    PubMed

    Kamle, Suchitra; Ali, Sher

    2013-06-15

    Genetically modified (GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis (Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism (GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities, detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted. PMID:23566850

  10. Electrospun fiber membranes enable proliferation of genetically modified cells

    PubMed Central

    Borjigin, Mandula; Eskridge, Chris; Niamat, Rohina; Strouse, Bryan; Bialk, Pawel; Kmiec, Eric B

    2013-01-01

    Polycaprolactone (PCL) and its blended composites (chitosan, gelatin, and lecithin) are well-established biomaterials that can enrich cell growth and enable tissue engineering. However, their application in the recovery and proliferation of genetically modified cells has not been studied. In the study reported here, we fabricated PCL-biomaterial blended fiber membranes, characterized them using physicochemical techniques, and used them as templates for the growth of genetically modified HCT116-19 colon cancer cells. Our data show that the blended polymers are highly miscible and form homogenous electrospun fiber membranes of uniform texture. The aligned PCL nanofibers support robust cell growth, yielding a 2.5-fold higher proliferation rate than cells plated on standard plastic plate surfaces. PCL-lecithin fiber membranes yielded a 2.7-fold higher rate of proliferation, while PCL-chitosan supported a more modest growth rate (1.5-fold higher). Surprisingly, PCL-gelatin did not enhance cell proliferation when compared to the rate of cell growth on plastic surfaces. PMID:23467983

  11. A 90-day toxicology study of transgenic lysine-rich maize grain (Y642) in Sprague-Dawley rats.

    PubMed

    He, Xiao Yun; Tang, Mao Zhi; Luo, Yun Bo; Li, Xin; Cao, Si Shuo; Yu, Jing Juan; Delaney, Bryan; Huang, Kun Lun

    2009-02-01

    The gene for a lysine-rich protein (sb401) obtained from potatoes (Solanum berthaultii) was inserted into maize seed to produce Y642 transgenic maize. Compositional analysis of Y642 grain demonstrated that the concentrations of lysine and total protein were higher than those observed in maize grain from a near-isogenic non-genetically modified (non-GM) commercially available control quality protein maize (Nongda 108). The safety of Y642 maize grain was assessed by comparison of toxicology response variables in Sprague-Dawley (SD) rats consuming diets containing Y642 maize grain with those containing Nongda 108 maize grain. Maize grains from Y642 or Nongda 108 were incorporated into rodent diets at low (30%) or high concentrations (76%) and administered to SD rats (n=10/sex/group) for 90 days. An additional group of negative control group of rats (n=10/sex/group) were fed AIN93G diets. No adverse diet-related differences in body weights, feed consumption/utilization, clinical chemistry, hematology, absolute and relative organ weights were observed. Further, no differences in gross or microscopic pathology were observed between rats consuming diets with Y642 maize grain compared with rats consuming diets containing Nongda 108 maize grain. These results demonstrated that Y642 lysine-rich maize is as safe and nutritious as conventional quality protein maize. PMID:19073230

  12. Detection and quantification of genetically modified organisms using very short, locked nucleic acid TaqMan probes.

    PubMed

    Salvi, Sergio; D'Orso, Fabio; Morelli, Giorgio

    2008-06-25

    Many countries have introduced mandatory labeling requirements on foods derived from genetically modified organisms (GMOs). Real-time quantitative polymerase chain reaction (PCR) based upon the TaqMan probe chemistry has become the method mostly used to support these regulations; moreover, event-specific PCR is the preferred method in GMO detection because of its high specificity based on the flanking sequence of the exogenous integrant. The aim of this study was to evaluate the use of very short (eight-nucleotide long), locked nucleic acid (LNA) TaqMan probes in 5'-nuclease PCR assays for the detection and quantification of GMOs. Classic TaqMan and LNA TaqMan probes were compared for the analysis of the maize MON810 transgene. The performance of the two types of probes was tested on the maize endogenous reference gene hmga, the CaMV 35S promoter, and the hsp70/cryIA(b) construct as well as for the event-specific 5'-integration junction of MON810, using plasmids as standard reference molecules. The results of our study demonstrate that the LNA 5'-nuclease PCR assays represent a valid and reliable analytical system for the detection and quantification of transgenes. Application of very short LNA TaqMan probes to GMO quantification can simplify the design of 5'-nuclease assays. PMID:18494480

  13. Isothermal amplification of genetically modified DNA sequences directly from plant tissues lowers the barriers to high-throughput and field-based genotyping.

    PubMed

    Lee, David; La Mura, Maurizio; Allnutt, Theo; Powell, Wayne; Greenland, Andy

    2009-10-28

    DNA extractions are a major cost for high-throughput genotyping. The loop-mediated isothermal amplification (LAMP) assay has been used for the detection of two genetically modified (GM) related sequences. The amplification of target DNA sequences from leaf and maize seed tissues prepared with minimum preparative treatment (disruption in water) demonstrates the ability of LAMP to work in conditions normally inhibitive to PCRs. The wide dynamic range of detection in these samples suggests that LAMP is highly sensitive even when the target is presented in such a crude form. LAMP offers a means of reducing genotyping costs as well as simplifying testing procedures. PMID:19772345

  14. Region-Specific Cis- and Trans-Acting Factors Contribute to Genetic Variability in Meiotic Recombination in Maize

    PubMed Central

    Timmermans, MCP.; Das, O. P.; Bradeen, J. M.; Messing, J.

    1997-01-01

    Understanding the genetic basis for variability in recombination rates is important for general genetic studies and plant-breeding efforts. Earlier studies had suggested increased recombination frequencies in particular F(2) populations derived from the maize inbred A188. A detailed phenotypic and molecular analysis was undertaken to extend these observations and dissect the responsible factors. A heritable increase in recombination in the sh1-bz1 interval was observed in these populations. A factor causing an approximate twofold increase mapped to the A188 Sh1-Bz1 region, behaved as a dominant, cis-acting factor, affected recombination equally in male and female sporogenesis and did not reduce the wellstudied complete interference in the adjacent bz1-wx interval. This factor also did not increase recombination frequencies in the c1-sh1 and bz1-wx intervals, demonstrating independent control of recombination in adjacent intervals. Additional phenotypic analysis of recombination in the c1-sh1 and bz1-wx intervals and RFLP analysis of recombination along chromosomes 7 and 5 suggested that heritable factors controlling recombination in these intervals act largely independently and in trans. Our results show that recombination in these populations, and possibly maize in general, is controlled by both cis- and transacting factors that affect specific chromosomal regions. PMID:9215911

  15. Genetic Modifiers of Duchenne Muscular Dystrophy and Dilated Cardiomyopathy

    PubMed Central

    Politano, Luisa; Melacini, Paola; Calore, Chiara; Polo, Angela; Vianello, Sara; Sorarù, Gianni; Semplicini, Claudio; Pantic, Boris; Taglia, Antonella; Picillo, Ester; Magri, Francesca; Gorni, Ksenija; Messina, Sonia; Vita, Gian Luca; Vita, Giuseppe; Comi, Giacomo P.; Ermani, Mario; Calvo, Vincenzo; Angelini, Corrado; Hoffman, Eric P.; Pegoraro, Elena

    2015-01-01

    Objective Dilated cardiomyopathy (DCM) is a major complication and leading cause of death in Duchenne muscular dystrophy (DMD). DCM onset is variable, suggesting modifier effects of genetic or environmental factors. We aimed to determine if polymorphisms previously associated with age at loss of independent ambulation (LoA) in DMD (rs28357094 in the SPP1 promoter, rs10880 and the VTTT/IAAM haplotype in LTBP4) also modify DCM onset. Methods A multicentric cohort of 178 DMD patients was genotyped by TaqMan assays. We performed a time-to-event analysis of DCM onset, with age as time variable, and finding of left ventricular ejection fraction < 50% and/or end diastolic volume > 70 mL/m2 as event (confirmed by a previous normal exam < 12 months prior); DCM-free patients were censored at the age of last echocardiographic follow-up. Results Patients were followed up to an average age of 15.9 ± 6.7 years. Seventy-one/178 patients developed DCM, and median age at onset was 20.0 years. Glucocorticoid corticosteroid treatment (n = 88 untreated; n = 75 treated; n = 15 unknown) did not have a significant independent effect on DCM onset. Cardiological medications were not administered before DCM onset in this population. We observed trends towards a protective effect of the dominant G allele at SPP1 rs28357094 and recessive T allele at LTBP4 rs10880, which was statistically significant in steroid-treated patients for LTBP4 rs10880 (< 50% T/T patients developing DCM during follow-up [n = 13]; median DCM onset 17.6 years for C/C-C/T, log-rank p = 0.027). Conclusions We report a putative protective effect of DMD genetic modifiers on the development of cardiac complications, that might aid in risk stratification if confirmed in independent cohorts. PMID:26513582

  16. Mixtures of genetically modified wheat lines outperform monocultures.

    PubMed

    Zeller, Simon L; Kalinina, Olena; Flynn, Dan F B; Schmid, Bernhard

    2012-09-01

    Biodiversity research shows that diverse plant communities are more stable and productive than monocultures. Similarly, populations in which genotypes with different pathogen resistance are mixed may have lower pathogen levels and thus higher productivity than genetically uniform populations. We used genetically modified (GM) wheat as a model system to test this prediction, because it allowed us to use genotypes that differed only in the trait pathogen resistance but were otherwise identical. We grew three such genotypes or lines in monocultures or two-line mixtures. Phenotypic measurements were taken at the level of individual plants and of entire plots (population level). We found that resistance to mildew increased with both GM richness (0, 1, or 2 Pm3 transgenes with different resistance specificities per plot) and GM concentration (0%, 50%, or 100% of all plants in a plot with a Pm3 transgene). Plots with two transgenes had 34.6% less mildew infection and as a consequence 7.3% higher seed yield than plots with one transgene. We conclude that combining genetic modification with mixed cropping techniques could be a promising approach to increase sustainability and productivity in agricultural systems, as the fitness cost of stacking transgenes within individuals may thus be avoided. PMID:23092018

  17. Molecular scissors and their application in genetically modified farm animals.

    PubMed

    Petersen, Bjoern; Niemann, Heiner

    2015-06-01

    Molecular scissors (MS), incl. Zinc Finger Nucleases (ZFN), Transcription-activator like endoncleases (TALENS) and meganucleases possess long recognition sites and are thus capable of cutting DNA in a very specific manner. These molecular scissors mediate targeted genetic alterations by enhancing the DNA mutation rate via induction of double-strand breaks at a predetermined genomic site. Compared to conventional homologous recombination based gene targeting, MS can increase the targeting rate 10,000-fold, and gene disruption via mutagenic DNA repair is stimulated at a similar frequency. The successful application of different MS has been shown in different organisms, including insects, amphibians, plants, nematodes, and mammals, including humans. Recently, another novel class of molecular scissors was described that uses RNAs to target a specific genomic site. The CRISPR/Cas9 system is capable of targeting even multiple genomic sites in one shot and thus could be superior to ZFNs or TALEN, especially by its easy design. MS can be successfully employed for improving the understanding of complex physiological systems, producing transgenic animals, incl. creating large animal models for human diseases, creating specific cell lines, and plants, and even for treating human genetic diseases. This review provides an update on molecular scissors, their underlying mechanism and focuses on new opportunities for generating genetically modified farm animals. PMID:25603988

  18. Genetic Analysis of Grain Filling Rate Using Conditional QTL Mapping in Maize

    PubMed Central

    Cui, Zitian; Hu, Yanmin; Wang, Bin; Tang, Jihua

    2013-01-01

    The grain filling rate (GFR) is an important dynamic trait that determines the final grain yield and is controlled by a network of genes and environment factors. To determine the genetic basis of the GFR, a conditional quantitative trait locus (QTL) analysis method was conducted using time-related phenotypic values of the GFR collected from a set of 243 immortalized F2 (IF2) population, which were evaluated at two locations over 2 years. The GFR gradually rose in the 0–15 days after pollination (DAP) and 16–22 DAP, reaching a maximum at 23–29 DAP, and then gradually decreasing. The variation of kernel weight (KW) was mainly decided by the GFR, and not by the grain filling duration (GFD). Thirty-three different unconditional QTLs were identified for the GFR at the six sampling stages over 2 years. Among them, QTLs qGFR7b, qGFR9 and qGFR6d were identified at the same stages at two locations over 2 years. In addition, 14 conditional QTLs for GFR were detected at five stages. The conditional QTL qGFR7c was identified at stage V|IV (37–43 DAP) at two locations over 2 years, and qGFR7b was detected at the sixth stage (44–50 DAP) in all four environments, except at Anyang location in 2009. QTLs qQTL7b and qQTL6f were identified by unconditional and conditional QTL mapping at the same stages, and might represent major QTLs for regulating the GFR in maize in the IF2 population. Moreover, most of the QTLs identified were co-located with QTLs from previous studies that were associated with GFR, enzyme activities of starch synthesis, soluble carbohydrates, and grain filling related genes. These results indicated that the GFR is regulated by many genes, which are specifically expressed at different grain filling stages, and the specific expression of the genes between 16–35 DAP might be very important for deciding the final kernel weight. PMID:23441180

  19. Proliferation of Genetically Modified Human Cells on Electrospun Nanofiber Scaffolds

    PubMed Central

    Borjigin, Mandula; Strouse, Bryan; Niamat, Rohina A; Bialk, Pawel; Eskridge, Chris; Xie, Jingwei; Kmiec, Eric B

    2012-01-01

    Gene editing is a process by which single base mutations can be corrected, in the context of the chromosome, using single-stranded oligodeoxynucleotides (ssODNs). The survival and proliferation of the corrected cells bearing modified genes, however, are impeded by a phenomenon known as reduced proliferation phenotype (RPP); this is a barrier to practical implementation. To overcome the RPP problem, we utilized nanofiber scaffolds as templates on which modified cells were allowed to recover, grow, and expand after gene editing. Here, we present evidence that some HCT116-19, bearing an integrated, mutated enhanced green fluorescent protein (eGFP) gene and corrected by gene editing, proliferate on polylysine or fibronectin-coated polycaprolactone (PCL) nanofiber scaffolds. In contrast, no cells from the same reaction protocol plated on both regular dish surfaces and polylysine (or fibronectin)-coated dish surfaces proliferate. Therefore, growing genetically modified (edited) cells on electrospun nanofiber scaffolds promotes the reversal of the RPP and increases the potential of gene editing as an ex vivo gene therapy application. PMID:23212298

  20. Genetic architecture of maize kernel composition in the nested association mapping and inbred association panels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize kernel plays a critical role in feeding humans and livestock around the world and in a wide array of industrial applications. An understanding of the regulation of kernel starch, protein, and oil is needed in order to manipulate composition to meet future needs. We conducted quantitative...

  1. Maize centromeres expand and adopt a uniform size in the genetic background of oat

    PubMed Central

    Wang, Kai; Wu, Yufeng; Zhang, Wenli; Dawe, R. Kelly; Jiang, Jiming

    2014-01-01

    Most existing centromeres may have originated as neocentromeres that activated de novo from noncentromeric regions. However, the evolutionary path from a neocentromere to a mature centromere has been elusive. Here we analyzed the centromeres of nine chromosomes that were transferred from maize into oat as the result of an inter-species cross. Centromere size and location were assayed by chromatin immunoprecipitation for the histone variant CENH3, which is a defining feature of functional centromeres. Two isolates of maize chromosome 3 proved to contain neocentromeres in the sense that they had moved from the original site, whereas the remaining seven centromeres (1, 2, 5, 6, 8, 9, and 10) were retained in the same area in both species. In all cases, the CENH3-binding domains were dramatically expanded to encompass a larger area in the oat background (∼3.6 Mb) than the average centromere size in maize (∼1.8 Mb). The expansion of maize centromeres appeared to be restricted by the transcription of genes located in regions flanking the original centromeres. These results provide evidence that (1) centromere size is regulated; (2) centromere sizes tend to be uniform within a species regardless of chromosome size or origin of the centromere; and (3) neocentromeres emerge and expand preferentially in gene-poor regions. Our results suggest that centromere size expansion may be a key factor in the survival of neocentric chromosomes in natural populations. PMID:24100079

  2. Genetic Dissection High Temperature Tolerance Traits in Maize-a QTL Mapping Approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High temperature (HT) stress severely limits plant productivity and causes extensive economic loss to US agriculture. Understanding HT adaptation mechanisms in crop plants is crucial to the success of developing HT tolerant varieties. Maize inbred lines vary greatly in HT tolerance based on field ...

  3. Deciphering maize genetics and ecology to reduce insect damage and aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ear-colonizing insects and diseases, which reduce yield and impose health threats via mycotoxin contaminations, are critical impediments for maize production in the southern US states. To address this problem a combination of basic and applied research approaches are being conducted by the interdis...

  4. Genetic analysis and characterization of a new maize association mapping panel for quantitative trait loci dissesction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Association mapping based on linkage disequilibrium provides a promising method to identify genes responsible for quantitative variation underlying complex traits. Presented here is a maize association mapping panel consisting of 155 diverse (mainly temperate inbred lines) suitable for marker-trait ...

  5. GENETIC AND MOLECULAR CHARACTERIZATION OF THE MAIZE RP3 RUST RESISTANCE LOCUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding ...

  6. Genetic control of photoperiod sensitivity in maize revealed by joint multiple population analysis.

    PubMed

    Coles, Nathan D; McMullen, Michael D; Balint-Kurti, Peter J; Pratt, Richard C; Holland, James B

    2010-03-01

    Variation in maize for response to photoperiod is related to geographical adaptation in the species. Maize possesses homologs of many genes identified as regulators of flowering time in other species, but their relation to the natural variation for photoperiod response in maize is unknown. Candidate gene sequences were mapped in four populations created by crossing two temperate inbred lines to two photoperiod-sensitive tropical inbreds. Whole-genome scans were conducted by high-density genotyping of the populations, which were phenotyped over 3 years in both short- and long-day environments. Joint multiple population analysis identified genomic regions controlling photoperiod responses in flowering time, plant height, and total leaf number. Four key genome regions controlling photoperiod response across populations were identified, referred to as ZmPR1-4. Functional allelic differences within these regions among phenotypically similar founders suggest distinct evolutionary trajectories for photoperiod adaptation in maize. These regions encompass candidate genes CCA/LHY, CONZ1, CRY2, ELF4, GHD7, VGT1, HY1/SE5, TOC1/PRR7/PPD-1, PIF3, ZCN8, and ZCN19. PMID:20008571

  7. Genetic and biochemical differences in populations bred for extremes in maize grain methionine content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methionine is an important nutrient in animal feed and several approaches have been developed to increase methionine concentration in maize (Zea mays L.) grain. One approach is through traditional breeding using recurrent selection. Two populations selected were selected for high and low methionin...

  8. Characterization, Genetic Variation, and Combining Ability of Maize Traits Beneficial to the Production of Cellulosic Ethanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize stover has been identified as an important feedstock for the production of cellulosic ethanol. Our objectives were to measure hybrid effect and combining ability patterns of traits related to cellulosic ethanol production, determine if germplasm and mutations used for silage production would a...

  9. Genetic Architecture of Maize Kernel Quality in the Nested Association Mapping (NAM) Population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many studies have been conducted to identify genes (quantitative trait loci; QTL) underlying kernel quality traits. However, these studies were limited to analyzing two parents at once and often resulted in low resolution mapping of QTL. The maize nested association mapping (NAM) population is a r...

  10. Genetic and physiological analysis of iron content and bioavailability in maize kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is a major cereal crop widely consumed in developing countries, which have a high prevalence of iron (Fe) deficiency including anemia. The major cause of Fe deficiency in these countries is inadequate intake of bioavailable Fe, of which poverty is a major contributing factor. Therefore, biof...

  11. THE GENETIC STRUCTURE OF A MAIZE SYNTHETIC: THE ROLE OF DOMINANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In selection programs, the covariance between parents and offspring largely determines the success of selection. We have estimated the variances and covariances between noninbred individuals and both their inbred and outbred progeny in the non-stiff stalk maize population BSCB1(R)C13. Estimation o...

  12. IBM MAIZE COMMUNITY RESOURCES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Mapping Project is funded to develop a physical map of maize that will be anchored to the genetic map by molecular and trait markers, to develop data management resources allowing for analysis and curation, and to provide accessibility to the public of all of the resources developed throug...

  13. The MaizeGDB Genome Browser

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of an effort to develop MaizeGDB as a more sequence-centric resource, we implemented a genome browser based on information we gathered by surveying the community of maize geneticists. Based on commu...

  14. Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant Inbred Line Population[OPEN

    PubMed Central

    Wen, Weiwei; Li, Kun; Alseekh, Saleh; Omranian, Nooshin; Zhao, Lijun; Zhou, Yang; Xiao, Yingjie; Jin, Min; Yang, Ning; Liu, Haijun; Florian, Alexandra; Li, Wenqiang; Pan, Qingchun; Nikoloski, Zoran; Yan, Jianbing; Fernie, Alisdair R.

    2015-01-01

    Deciphering the influence of genetics on primary metabolism in plants will provide insights useful for genetic improvement and enhance our fundamental understanding of plant growth and development. Although maize (Zea mays) is a major crop for food and feed worldwide, the genetic architecture of its primary metabolism is largely unknown. Here, we use high-density linkage mapping to dissect large-scale metabolic traits measured in three different tissues (leaf at seedling stage, leaf at reproductive stage, and kernel at 15 d after pollination [DAP]) of a maize recombinant inbred line population. We identify 297 quantitative trait loci (QTLs) with moderate (86.2% of the mapped QTL, R2 = 2.4 to 15%) to major effects (13.8% of the mapped QTL, R2 >15%) for 79 primary metabolites across three tissues. Pairwise epistatic interactions between these identified loci are detected for more than 25.9% metabolites explaining 6.6% of the phenotypic variance on average (ranging between 1.7 and 16.6%), which implies that epistasis may play an important role for some metabolites. Key candidate genes are highlighted and mapped to carbohydrate metabolism, the tricarboxylic acid cycle, and several important amino acid biosynthetic and catabolic pathways, with two of them being further validated using candidate gene association and expression profiling analysis. Our results reveal a metabolite-metabolite-agronomic trait network that, together with the genetic determinants of maize primary metabolism identified herein, promotes efficient utilization of metabolites in maize improvement. PMID:26187921

  15. Biological and biomedical aspects of genetically modified food.

    PubMed

    Celec, Peter; Kukucková, Martina; Renczésová, Veronika; Natarajan, Satheesh; Pálffy, Roland; Gardlík, Roman; Hodosy, Július; Behuliak, Michal; Vlková, Barbora; Minárik, Gabriel; Szemes, Tomás; Stuchlík, Stanislav; Turna, Ján

    2005-12-01

    Genetically modified (GM) foods are the product of one of the most progressive fields of science-biotechnology. There are major concerns about GM foods in the public; some of them are reasonable, some of them are not. Biomedical risks of GM foods include problems regarding the potential allergenicity, horizontal gene transfer, but environmental side effects on biodiversity must also be recognized. Numerous methods have been developed to assess the potential risk of every GM food type. Benefits of the first generation of GM foods were oriented towards the production process and companies, the second generation of GM foods offers, on contrary, various advantages and added value for the consumer. This includes improved nutritional composition or even therapeutic effects. Recombinant probiotics and the principle of alternative gene therapy represent the latest approach of using GM organisms for biomedical applications. This article tries to summarize and to explain the problematic topic of GM food. PMID:16298508

  16. Genetically modified mosquito: the Malaysian public engagement experience.

    PubMed

    Subramaniam, T S Saraswathy; Lee, Han Lim; Ahmad, Nazni Wasi; Murad, Shahnaz

    2012-11-01

    On December 21, 2010, 6000 genetically modified (GM) mosquitoes were released in an uninhabited forest in Malaysia. The purpose of the deliberate release was a limited “marked release and recapture” (MRR) experiment, a standard ecological method in entomology, to evaluate under field conditions, the flight distance and longevity of the sterile male Aedes aegypti strain OX513A(My1), a GM strain. As with any other GM technologies, the release was received with mixed responses. As the scientific community debate over the public engagement strategies for similar GM releases, dengue incidence continues to rise with a heavy toll on morbidity, mortality and healthcare budgets. Meanwhile the wild female Aedes aegypti continues to breed offspring, surviving and evading conventional interventions for vector control. PMID:23125042

  17. Methods to Study Metastasis in Genetically Modified Mice.

    PubMed

    Kabeer, Farhia; Beverly, Levi J; Darrasse-Jèze, Guillaume; Podsypanina, Katrina

    2016-01-01

    Metastasis is often modeled by xenotransplantation of cell lines in immunodeficient mice. A wealth of information about tumor cell behavior in the new environment is obtained from these efforts. Yet by design, this approach is "tumor-centric," as it focuses on cell-autonomous determinants of human tumor dissemination in mouse tissues, in effect using the animal body as a sophisticated "Petri dish" providing nutrients and support for tumor growth. Transgenic or gene knockout mouse models of cancer allow the study of tumor spread as a systemic disease and offer a complimentary approach for studying the natural history of cancer. This introduction is aimed at describing the overall methodological approach to studying metastasis in genetically modified mice, with a particular focus on using animals with regulated expression of potent human oncogenes in the breast. PMID:26832689

  18. Risk assessment of genetically modified crops for nutrition and health.

    PubMed

    Magaña-Gómez, Javier A; de la Barca, Ana M Calderón

    2009-01-01

    The risk assessment of genetically modified (GM) crops for human nutrition and health has not been systematic. Evaluations for each GM crop or trait have been conducted using different feeding periods, animal models, and parameters. The most common result is that GM and conventional sources induce similar nutritional performance and growth in animals. However, adverse microscopic and molecular effects of some GM foods in different organs or tissues have been reported. Diversity among the methods and results of the risk assessments reflects the complexity of the subject. While there are currently no standardized methods to evaluate the safety of GM foods, attempts towards harmonization are on the way. More scientific effort is necessary in order to build confidence in the evaluation and acceptance of GM foods. PMID:19146501

  19. The case for genetically modified crops with a poverty focus.

    PubMed

    Atkinson, H J; Green, J; Cowgill, S; Levesley, A

    2001-03-01

    Recently seven National Academies of Science produced a report on transgenic plants and world agriculture. The report provides scientific perspectives to the ongoing public debate about the potential role for transgenic technology in world agriculture. In this article, we develop the themes of the report and emphasize the potential for future genetically modified (GM) crops with a poverty focus, emphasizing the potential of GM resistance to plant parasitic nematodes for subsistence potato farmers in Bolivia. We judge that a range of incremental gains to crop yields from many transgenes are valuable for future world security. We advocate the establishment of a standard that GM crops must achieve before they are both biosafe and appropriate for resource-poor farmers and we believe that the best interests of the poor require biotechnologists to work towards that objective. PMID:11179801

  20. Genetically modified stem cells for the treatment of neurological diseases.

    PubMed

    Mitrecic, Dinko; Nicaise, Charles; Klimaschewski, Lars; Gajovic, Srecko; Bohl, Delphine; Pochet, Roland

    2012-01-01

    The central nervous system has a very poor regenerative potential and is difficult to access. This partly explains why neurological diseases often lack appropriate therapeutic options and represent the most significant burden for healthcare systems. Progress in understanding the molecular background of neurological diseases requires innovative approaches offering new hope for the patients. One of the most intriguing and promising options is the combination of stem cells with gene therapy. Unlike fibroblasts, stem cells exhibit a high tropism for disease-affected tissue and integrate into the nervous tissue. This makes them ideal candidates for the production and delivery of molecules of interest for treating the nervous system. This article reviews the methodology for obtaining pluripotent stem cells (iPSCs) as precursors for neuronal cells, glial cells and the current state of the art in applications of genetically modified stem cells in animal models of neurodegenerative diseases, stroke, axonal damage, tumors and epilepsy. PMID:22201944

  1. Environmental risk assessment for medicinal products containing genetically modified organisms.

    PubMed

    Anliker, B; Longhurst, S; Buchholz, C J

    2010-01-01

    Many gene therapy medicinal products and also some vaccines consist of, or contain, genetically modified organisms (GMOs), which require specific consideration in the environmental risk assessment (ERA) before marketing authorisation or clinical trial applications. The ERA is performed in order to identify the potential risks for public health and the environment, which may arise due to the clinical use of these medicinal products. If such environmental risks are identified and considered as not acceptable, the ERA should go on to propose appropriate risk management strategies capable to reduce these risks. This article will provide an overview of the legal basis and requirements for the ERA of GMO-containing medicinal products in the context of marketing authorisation in the EU and clinical trials in Germany. Furthermore, the scientific principles and methodology that generally need to be followed when preparing an ERA for GMOs are discussed. PMID:19940966

  2. Genetically modified crops: methodology, benefits, regulation and public concerns.

    PubMed

    Halford, N G; Shewry, P R

    2000-01-01

    The genetic modification of crop plants from the methodology involved in their production through to the current debate on their use in agriculture are reviewed. Techniques for plant transformation by Agrobacterium tumefaciens and particle bombardment, and for the selection of transgenic plants using marker genes are described. The benefits of currently available genetically modified (GM) crops in reducing waste and agrochemical use in agriculture, and the potential of the technology for further crop improvement in the future are discussed. The legal requirements for containment of novel GM crops and the roles of relevant regulatory bodies in ensuring that GM crops and food are safe are summarized. Some of the major concerns of the general public regarding GM crops and food: segregation of GM and non-GM crops and cross-pollination between GM crops and wild species, the use of antibiotic resistance marker genes, the prevention of new allergens being introduced in to the food chain and the relative safety of GM and non-GM foods are considered. Finally, the current debate on the use of GM crops in agriculture and the need for the government, scientists and industry to persevere with the technology in the face of widespread hostility is studied. PMID:10885105

  3. Passenger Mutations Confound Interpretation of All Genetically Modified Congenic Mice.

    PubMed

    Vanden Berghe, Tom; Hulpiau, Paco; Martens, Liesbet; Vandenbroucke, Roosmarijn E; Van Wonterghem, Elien; Perry, Seth W; Bruggeman, Inge; Divert, Tatyana; Choi, Sze Men; Vuylsteke, Marnik; Shestopalov, Valery I; Libert, Claude; Vandenabeele, Peter

    2015-07-21

    Targeted mutagenesis in mice is a powerful tool for functional analysis of genes. However, genetic variation between embryonic stem cells (ESCs) used for targeting (previously almost exclusively 129-derived) and recipient strains (often C57BL/6J) typically results in congenic mice in which the targeted gene is flanked by ESC-derived passenger DNA potentially containing mutations. Comparative genomic analysis of 129 and C57BL/6J mouse strains revealed indels and single nucleotide polymorphisms resulting in alternative or aberrant amino acid sequences in 1,084 genes in the 129-strain genome. Annotating these passenger mutations to the reported genetically modified congenic mice that were generated using 129-strain ESCs revealed that nearly all these mice possess multiple passenger mutations potentially influencing the phenotypic outcome. We illustrated this phenotypic interference of 129-derived passenger mutations with several case studies and developed a Me-PaMuFind-It web tool to estimate the number and possible effect of passenger mutations in transgenic mice of interest. PMID:26163370

  4. Genetically modified foods, science, consumers and the media.

    PubMed

    Rowland, I R

    2002-02-01

    In contrast to the situation in the USA, where a wide range of genetically modified (GM) foods is available, in Europe very few GM products have been approved for marketing as foods, and there is widespread public concern about their safety and environmental impact. The marketing of a GM crop for food use in Europe falls under the EC novel foods regulations, and applications require the submission of an extensive dossier of information. The safety evaluation of GM foods presents considerable problems both in the conduct and interpretation of experimental studies, because conventional toxicity tests used in the evaluation of simple chemicals may not be appropriate for whole foods. To rationalise the safety evaluation process and to circumvent the difficulties in toxicological assessment of food materials, the concept of substantial equivalence has been developed. The concept is that if it can be demonstrated that the novel food is essentially similar to its conventional counterpart in terms of critical nutritional or anutritional components, then it is likely to be no more or less toxic than the latter. The possible introduction of unintended effects by the genetic modification process is particularly problematic for the safety evaluation process. The new genomic and post-genomic techniques are potentially valuable in the safety evaluation of GM foods, although they are as yet in their infancy. PMID:12002791

  5. Genetically modified plants for improved trace element nutrition.

    PubMed

    Lönnerdal, Bo

    2003-05-01

    Deficiencies of iron and zinc are common worldwide. Various strategies have been used to combat these deficiencies including supplementation, food fortification and modification of food preparation and processing methods. A new possible strategy is to use biotechnology to improve trace element nutrition. Genetic engineering can be used in several ways; the most obvious is to increase the trace element content of staple foods such as cereals and legumes. This may be achieved by introduction of genes that code for trace element-binding proteins, overexpression of storage proteins already present and/or increased expression of proteins that are responsible for trace element uptake into plants. However, even very high levels of expression may not substantially increase the iron and zinc contents unless many atoms of trace elements are bound per protein molecule. Another possibility is to introduce a protein that specifically enhances trace element absorption even in the presence of naturally occurring inhibitors, thus improving bioavailability. Genetically modifying plants so that their contents of inhibitors of trace element absorption such as phytate are substantially reduced is another approach. Increasing the expression of compounds that enhance trace element absorption such as ascorbic acid is also a possibility, although this has received limited attention so far. Iron absorption may be increased by higher ascorbic or citric acid content but require overexpression of enzymes that are involved in the synthetic pathways. Finally, a combination of all of these approaches perhaps complemented with conventional breeding techniques may prove successful. PMID:12730450

  6. Environmental and Genetic Modifiers of squint Penetrance during Zebrafish Embryogenesis

    PubMed Central

    Pei, Wuhong; Williams, P. Huw; Clark, Matthew D.; Stemple, Derek L.; Feldman, Benjamin

    2007-01-01

    The Nodal-related subgroup of the TGFβ superfamily of secreted cytokines regulates the specification of the mesodermal and endodermal germ layers during gastrulation. Two Nodal-related proteins - Squint (Sqt) and Cyclops (Cyc) - are expressed during germ-layer specification in zebrafish. Genetic sqt mutant phenotypes have defined a variable requirement for zygotic Sqt, but not for maternal Sqt, in midline mesendoderm development. However a comparison of phenotypes arising from oocytes or zygotes injected with Sqt antisense morpholinos has suggested a novel requirement for maternal Sqt in dorsal specification. In this study we examined maternal-zygotic mutants for each of two sqt alleles and we also compared phenotypes of closely related zygotic and maternal-zygotic sqt mutants. Each of these approaches indicated there is no general requirement for maternal Sqt. To better understand the dispensability of maternal and zygotic Sqt, we sought out developmental contexts that more rigorously demand intact Sqt signalling. We found that sqt penetrance is influenced by genetic modifiers, by environmental temperature, by levels of residual Activin-like activity and by Heat-Shock Protein 90 (HSP90) activity. Therefore, Sqt may confer an evolutionary advantage by protecting early-stage embryos against detrimental interacting alleles and environmental challenges. PMID:17583692

  7. Detection method for genetically modified papaya using duplex PCR.

    PubMed

    Yamaguchi, Akihiro; Shimizu, Kaori; Mishima, Takashi; Aoki, Nobutaro; Hattori, Hideki; Sato, Hidetaka; Ueda, Nobuo; Watanabe, Takahiro; Hino, Akihiro; Akiyama, Hiroshi; Maitani, Tamio

    2006-08-01

    A simple and rapid method for the identification of genetically modified (GM) papaya, derived from Line 55-1, was developed by modifying the Japanese official PCR method. Genomic DNA was directly extracted from the fresh fruit without the lyophilization step, using a commercial silica-based kit. To develop a duplex PCR method which simultaneously detects the GM papaya-specific gene and the intrinsic papain gene, the papain 2-5'/3' (amplicon size; 184 bp) primer pair for the detection of the papain gene was newly designed within the region of the products (211 bp) amplified using the papain 1-5'/-3' primer pair adopted in the Japanese official PCR method. To detect the GM papaya-specific gene, the primer pair Nos C-5'/CaM N-3' described in the Japanese official method was used. The DNA sequences of the GM papaya gene and the intrinsic papain gene were co-amplified using the PCR method in a single tube. The developed duplex PCR method allows the simultaneous detection of the products by means of agarose gel electrophoresis or microchip electrophoresis. The proposed method for GM papaya identification is simple and rapid. PMID:16984033

  8. [Detection of genetically modified organisms obtained from food samples ].

    PubMed

    Monma, Kimio; Araki, Rie; Ichikawa, Hisatsugu; Sato, Masaki; Uno, Naomichi; Sato, Kazue; Tobe, Takashi; Kuribara, Hideo; Matsuoka, Takeshi; Hino, Akihiro; Saito, Kazuo

    2004-08-01

    Genetially modified organisms (GMOs) were explored in food samples obtained from November 2000 to March 2003 in the Tokyo area by using PCR and real-time PCR techniques. The existence of Roundup Ready Soybean (RRS) was surveyed in processed foods derived from soybeans, such as tofu, boiled soybean, kinako, nama-age, abura-age, natto, miso, soymilk and yuba. RRS was detected in 3 of 37 tofu, 2 of 3 nama-age, 2 of 3 yuba and 3 of 3 abura-age samples. The CBH351 in 70 processed corn foods, NewLeaf Plus and NewLeaf Y in 50 processed potato foods, and 55-1 papaya in 16 papayas were surveyed. These GMOs were not detected among the samples. Qualitative and quantitative analyses of RRS and genetically modified (GM) corn were performed in soybean, corn and semi-processed corn products such as corn meal, corn flour and corn grits. RRS was detected in 42 of 178 soybean samples, and the amount of RRS in RRS-positive samples was determined. The content was in the range of 0.1-1.4% in identity-preserved soybeans (non-GMO), and 49.8-78.8% in non-segregated soybeans. On the other hand, GM corns were detected in 8 of 26 samples. The amount of GM corn in GM corn-positive samples was in the range of 0.1-2.0%. PMID:15568468

  9. Genetic analysis of fumonisin production and virulence of Gibberella fujikuroi mating population A (Fusarium moniliforme) on maize (Zea mays) seedlings.

    PubMed Central

    Desjardins, A E; Plattner, R D; Nelsen, T C; Leslie, J F

    1995-01-01

    The phytopathogenic fungus Gibberella fujikuroi mating population A (anamorph, Fusarium moniliforme) produces fumonisins, which are toxic to a wide range of plant and animal species. Previous studies of field strains have identified a genetic locus, designated fum1, that can determine whether fumonisins are produced. To test the relationship between fumonisin production and virulence on maize seedlings, a cross between a fum1+ field strain that had a high degree of virulence and a fum1- field strain that had a low degree of virulence was made, and ascospore progeny were scored for these traits. Although a range of virulence levels was recovered among the progeny, high levels of virulence were associated with production of fumonisins, and highly virulent, fumonisin-nonproducing progeny were not obtained. A survey of field strains did identify a rare fumonisin-nonproducing strain that was quite high in virulence. Also, the addition of purified fumonisin B1 to virulence assays did not replicate all of the seedling blight symptoms obtained with autoclaved culture material containing fumonisin. These results support the hypothesis that fumonisin plays a role in virulence but also indicate that fumonisin production is not necessary or sufficient for virulence on maize seedlings. PMID:7887628

  10. A genetic test of bioactive gibberellins as regulators of heterosis in maize.

    PubMed

    Auger, D L; Peters, E M; Birchler, J A

    2005-01-01

    This study tested the hypothesis that gibberellin levels were responsible for the superior growth habit of hybrids (i.e., heterosis). If this were true, plants reduced in their capacity to produce gibberellin, such as maize plants homozygous for dwarf1 (d1), should display a lesser heterotic response. The d1 mutation was introgressed into two inbred lines of maize, B73 and Mo17, for seven generations. Plants segregating for the dwarf phenotype were produced both by self-fertilizing the introgressed inbred lines and by making reciprocal crosses between them to produce hybrids. Measurements were made of several physical traits. The results indicated that the hybrid dwarf plants experienced no loss of heterosis relative to their normal siblings. These results exclude the possibility that modulation of bioactive gibberellins is a major underlying basis of the heterotic response. PMID:16135703

  11. Genetic basis and detection of unintended effects in genetically modified crop plants.

    PubMed

    Ladics, Gregory S; Bartholomaeus, Andrew; Bregitzer, Phil; Doerrer, Nancy G; Gray, Alan; Holzhauser, Thomas; Jordan, Mark; Keese, Paul; Kok, Esther; Macdonald, Phil; Parrott, Wayne; Privalle, Laura; Raybould, Alan; Rhee, Seung Yon; Rice, Elena; Romeis, Jörg; Vaughn, Justin; Wal, Jean-Michel; Glenn, Kevin

    2015-08-01

    In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled "Genetic Basis of Unintended Effects in Modified Plants" was held in Ottawa, Canada, bringing together over 75 scientists from academia, government, and the agro-biotech industry. The objectives of the meeting were to explore current knowledge and identify areas requiring further study on unintended effects in plants and to discuss how this information can inform and improve genetically modified (GM) crop risk assessments. The meeting featured presentations on the molecular basis of plant genome variability in general, unintended changes at the molecular and phenotypic levels, and the development and use of hypothesis-driven evaluations of unintended effects in assessing conventional and GM crops. The development and role of emerging "omics" technologies in the assessment of unintended effects was also discussed. Several themes recurred in a number of talks; for example, a common observation was that no system for genetic modification, including conventional methods of plant breeding, is without unintended effects. Another common observation was that "unintended" does not necessarily mean "harmful". This paper summarizes key points from the information presented at the meeting to provide readers with current viewpoints on these topics. PMID:25716164

  12. Simultaneous detection of genetically modified organisms by multiplex ligation-dependent genome amplification and capillary gel electrophoresis with laser-induced fluorescence.

    PubMed

    García-Cañas, Virginia; Mondello, Monica; Cifuentes, Alejandro

    2010-07-01

    In this work, an innovative method useful to simultaneously analyze multiple genetically modified organisms is described. The developed method consists in the combination of multiplex ligation-dependent genome dependent amplification (MLGA) with CGE and LIF detection using bare-fused silica capillaries. The MLGA process is based on oligonucleotide constructs, formed by a universal sequence (vector) and long specific oligonucleotides (selectors) that facilitate the circularization of specific DNA target regions. Subsequently, the circularized target sequences are simultaneously amplified with the same couple of primers and analyzed by CGE-LIF using a bare-fused silica capillary and a run electrolyte containing 2-hydroxyethyl cellulose acting as both sieving matrix and dynamic capillary coating. CGE-LIF is shown to be very useful and informative for optimizing MLGA parameters such as annealing temperature, number of ligation cycles, and selector probes concentration. We demonstrate the specificity of the method in detecting the presence of transgenic DNA in certified reference and raw commercial samples. The method developed is sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 1% of GA21, 1% of MON863, and 1% of MON810 in maize samples with signal-to-noise ratios for the corresponding DNA peaks of 15, 12, and 26, respectively. These results demonstrate, to our knowledge for the first time, the great possibilities of MLGA techniques for genetically modified organisms analysis. PMID:20593401

  13. Development of an event-specific hydrolysis probe quantitative real-time polymerase chain reaction assay for Embrapa 5.1 genetically modified common bean (Phaseolus vulgaris).

    PubMed

    Treml, Diana; Venturelli, Gustavo L; Brod, Fábio C A; Faria, Josias C; Arisi, Ana C M

    2014-12-10

    A genetically modified (GM) common bean event, namely Embrapa 5.1, resistant to the bean golden mosaic virus (BGMV), was approved for commercialization in Brazil. Brazilian regulation for genetically modified organism (GMO) labeling requires that any food containing more than 1% GMO be labeled. The event-specific polymerase chain reaction (PCR) method has been the primary trend for GMO identification and quantitation because of its high specificity based on the flanking sequence. This work reports the development of an event-specific assay, named FGM, for Embrapa 5.1 detection and quantitation by use of SYBR Green or hydrolysis probe. The FGM assay specificity was tested for Embrapa 2.3 event (a noncommercial GM common bean also resistant to BGMV), 46 non-GM common bean varieties, and other crop species including maize, GM maize, soybean, and GM soybean. The FGM assay showed high specificity to detect the Embrapa 5.1 event. Standard curves for the FGM assay presented a mean efficiency of 95% and a limit of detection (LOD) of 100 genome copies in the presence of background DNA. The primers and probe developed are suitable for the detection and quantitation of Embrapa 5.1. PMID:25437743

  14. Mapping Quantitative Trait Loci Using Naturally Occurring Genetic Variance Among Commercial Inbred Lines of Maize (Zea mays L.)

    PubMed Central

    Zhang, Yuan-Ming; Mao, Yongcai; Xie, Chongqing; Smith, Howie; Luo, Lang; Xu, Shizhong

    2005-01-01

    Many commercial inbred lines are available in crops. A large amount of genetic variation is preserved among these lines. The genealogical history of the inbred lines is usually well documented. However, quantitative trait loci (QTL) responsible for the genetic variances among the lines are largely unexplored due to lack of statistical methods. In this study, we show that the pedigree information of the lines along with the trait values and marker information can be used to map QTL without the need of further crossing experiments. We develop a Monte Carlo method to estimate locus-specific identity-by-descent (IBD) matrices. These IBD matrices are further incorporated into a mixed-model equation for variance component analysis. QTL variance is estimated and tested at every putative position of the genome. The actual QTL are detected by scanning the entire genome. Applying this new method to a well-documented pedigree of maize (Zea mays L.) that consists of 404 inbred lines, we mapped eight QTL for the maize male flowering trait, growing degree day heat units to pollen shedding (GDUSHD). These detected QTL contributed >80% of the variance observed among the inbred lines. The QTL were then used to evaluate all the inbred lines using the best linear unbiased prediction (BLUP) technique. Superior lines were selected according to the estimated QTL allelic values, a technique called marker-assisted selection (MAS). The MAS procedure implemented via BLUP may be routinely used by breeders to select superior lines and line combinations for development of new cultivars. PMID:15716509

  15. Genetic Modifiers of Cardiorespiratory Fitness Response to Lifestyle Intervention

    PubMed Central

    Peter, Inga; Papandonatos, George D.; Belalcazar, L. Maria; Yang, Yao; Erar, Bahar; Jakicic, John M.; Unick, Jessica L.; Balasubramanyam, Ashok; Lipkin, Edward W.; Delahanty, Linda M.; Wagenknecht, Lynne E.; Wing, Rena R.; McCaffery, Jeanne M.; Huggins, Gordon S.

    2013-01-01

    Purpose Numerous prospective studies indicate that improved cardiorespiratory fitness reduces type 2 diabetes (T2D) risk and delays disease progression. We hypothesized that genetic variants modify fitness response to an intensive lifestyle intervention (ILI) in the Action for Health in Diabetes (Look AHEAD) randomized clinical trial, aimed to detect whether ILI will reduce cardiovascular events in overweight/obese subjects with T2D compared to a standard of care. Methods Polymorphisms in established fitness genes and in all loci assayed on the Illumina CARe iSelect chip were examined as predictors of change in metabolic equivalent (MET) level, estimated using a treadmill test, in response to a one-year intervention in 3,899 participants. Results We identified a significant signal in previously reported fitness-related gene RUNX1 that was associated with one-year METs response in ILI (0.19±0.04 MET less improvement per minor allele copy; P=1.9×10−5) and genotype-intervention interaction (P=4.8×10−3). In the chip-wide analysis, FKBP7 rs17225700 showed a significant association with ILI response among subjects not receiving beta-blocker medications (0.47±0.09 METs less improvement; P=5.3×10−7), and genotype-treatment interaction (P=5.3×10−5). GRAIL pathway-based analysis identified connections between associated genes, including those influencing vascular tone, muscle contraction, cardiac energy substrate dynamics, and muscle protein synthesis. Conclusions This is the first study to identify genetic variants associated with fitness responses to a randomized lifestyle intervention in overweight/obese diabetic individuals. RUNX1 and FKBP7, involved in erythropoesis and muscle protein synthesis, respectively, are related to change in cardiorespiratory fitness in response to exercise. PMID:23899896

  16. Forecasting the Feasibility of Implementing Isolation Perimeters Between GM and non-GM Maize Fields Under Agricultural Conditions

    NASA Astrophysics Data System (ADS)

    Devos, Yann; Cougnon, Mathias; Thas, Olivier; De Clercq, Eva M.; Cordemans, Karl; Reheul, Dirk

    2008-10-01

    Although spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm strategy to keep the adventitious presence of GM material in the harvests of neighboring non-GM maize fields due to cross-fertilizations below established labeling thresholds (and thus to ensure the spatial co-existence between maize cropping systems), the practical implementation of isolation perimeters attracted little research efforts. In this study, the feasibility of implementing isolation perimeters around GM maize fields is investigated. Using Geographic Information System datasets and Monte Carlo simulations, various scenarios differing in shares and spatial distributions of GM maize were tested for various isolation perimeters in six agricultural areas in Flanders. Factors that affect the feasibility of implementing isolation perimeters are discussed.

  17. A design for the control of apoptosis in genetically modified Saccharomyces cerevisiae.

    PubMed

    Nishida, Nao; Noguchi, Misa; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2014-01-01

    We have engineered a system that holds potential for use as a safety switch in genetically modified yeasts. Human apoptotic factor BAX (no homolog in yeast), under the control of the FBP1 (gluconeogenesis enzyme) promoter, was conditionally expressed to induce yeast cell apoptosis after glucose depletion. Such systems might prove useful for the safe use of genetically modified organisms. PMID:25036693

  18. Examining consumer behavior toward genetically modified (GM) food in Britain.

    PubMed

    Spence, Alexa; Townsend, Ellen

    2006-06-01

    This study examined behavior toward genetically modified (GM) food in a British community-based sample. We used an equivalent gain task in which participants actually received the options they chose to encourage truthful responding. In conjunction with this, theory of planned behavior (TPB) components were evaluated so as to examine the relative importance of behavioral influences in this domain. Here, the TPB was extended to include additional components to measure self-identity, moral norms, and emotional involvement. Results indicated that the monetary amounts participants accepted in preference to GM food were significantly lower than those accepted in preference to non-GM food. However, the vast majority of participants were indifferent between GM and non-GM food options. All TPB components significantly predicted behavioral intentions to try GM food, with attitudes toward GM being the strongest predictor. Self-identity and emotional involvement were also found to be significant predictors of behavioral intentions but moral norms were not. In addition, behavioral intentions significantly predicted behavior; however, PBC did not. An additional measure of participants' propensity to respond in a socially desirable manner indicated that our results were not influenced by self-presentation issues, giving confidence to our findings. Overall, it appears that the majority of participants (74.5%) would purchase GM food at some price. PMID:16834625

  19. Fast and sensitive detection of genetically modified yeasts in wine.

    PubMed

    León, Carlos; García-Cañas, Virginia; González, Ramón; Morales, Pilar; Cifuentes, Alejandro

    2011-10-21

    In this work, a novel screening methodology based on the combined use of multiplex polymerase chain reaction (PCR) and capillary gel electrophoresis with laser induced fluorescence (CGE-LIF) is developed for the fast and sensitive detection of genetically modified yeasts in wine. As model, a recombinant EKD-13 Saccaromyces cerevisiae strain was selected and different wines were prepared using either recombinant or conventional yeasts. Special emphasis is put on the yeast DNA extraction step, exploring different commercial and non-commercial methods, in order to overcome the important difficulty of obtaining amplifiable DNA from wine samples. To unequivocally detect the transgenic yeast, two specific segments of the transgenic construction were amplified. In addition, a third primer pair was used as amplification control to confirm the quality of the yeast DNA obtained from the extraction step. CGE-LIF provides high sensitivity, good analysis speed and impressive resolution of DNA fragments, making this technique very convenient to optimize multiplex PCR parameters and to analyze the amplified DNA fragments. Thus, the CGE-LIF method provided %RSD values for DNA migration times lower than 0.82% (n=10) with the same capillary and lower than 1.92% (n=15) with three different capillaries, allowing the adequate size determination of the PCR products with an error lower than 4% compared to the theoretically expected. The whole method developed in this work requires less than one working day and grants the sensitive detection of transgenic yeasts in wine samples. PMID:21296357

  20. Improved properties of micronized genetically modified flax fibers.

    PubMed

    Dymińska, Lucyna; Szatkowski, Michał; Wróbel-Kwiatkowska, Magdalena; Zuk, Magdalena; Kurzawa, Adam; Syska, Wojciech; Gągor, Anna; Zawadzki, Mirosław; Ptak, Maciej; Mączka, Mirosław; Hanuza, Jerzy; Szopa, Jan

    2012-12-15

    The aim of this study was to investigate the effect of micronization on the compound content, crystalline structure and physicochemical properties of fiber from genetically modified (GM) flax. The GM flax was transformed with three bacterial (Ralstonia eutropha) genes coding for enzymes of polyhydroxybutyrate (PHB) synthesis and under the control of the vascular bundle promoter. The modification resulted in fibers containing the 3-hydroxybutyrate polymer bound to cellulose via hydrogen and ester bonds and antioxidant compounds (phenolic acids, vanillin, vitexin, etc.). The fibers appeared to have a significantly decreased particle size after 20h of ball-milling treatment. Micronized fibers showed reduced phenolic contents and antioxidant capacity compared to the results for untreated fibers. An increased level of PHB was also detected. Micronization introduces structural changes in fiber constituents (cellulose, hemicellulose, pectin, lignin, PHB) and micronized fibers exhibit more functional groups (hydroxyl, carboxyl) derived from those constituents. It is thus concluded that micronization treatments improve the functional properties of the fiber components. PMID:23353730

  1. Do genetically modified plants impact arbuscular mycorrhizal fungi?

    PubMed

    Liu, Wenke

    2010-02-01

    The development and use of genetically modified plants (GMPs), as well as their ecological risks have been a topic of considerable public debate since they were first released in 1996. To date, no consistent conclusions have been drawn dealing with ecological risks on soil microorganisms of GMPs for the present incompatible empirical data. Arbuscular mycorrhizal fungi (AMF), important in regulating aboveground and underground processes in ecosystems, are the most crucial soil microbial community worthy of being monitored in ecological risks assessment of GMPs for their sensitivity to environmental alterations (plant, soil, climatic factor etc.). Based on current data, we suggest that there is a temporal-spatial relevance between expression and rhizosphere secretion of anti-disease and insecticidal proteins (e.g., Bt-Bacillus thuringiensis toxins) in and outer roots, and AMF intraradical and extraradical growth and development. Therefore, taking Bt transgenic plants (BTPs) for example, Bt insecticidal proteins constitutive expression and rhizosphere release during cultivation of BTPs may damage some critical steps of the AMF symbiotic development. More important, these processes of BTPs coincide with the entire life cycle of AMF annually, which may impact the diversity of AMF after long-term cultivation period. It is proposed that interactions between GMPs and AMF should be preferentially studied as an indicator for ecological impacts of GMPs on soil microbial communities. In this review, advances in impacts of GMPs on AMF and the effect mechanisms were summarized, highlighting the possible ecological implications of interactions between GMPs and AMF in soil ecosystems. PMID:19806453

  2. Genetically modified cotton in India and detection strategies.

    PubMed

    Randhawa, Gurinder Jit; Chhabra, Rashmi

    2013-01-01

    India is one of the largest cotton-growing countries. Cotton is a fiber crop with varied applications from making tiny threads to fashionable clothing in the textile sector. In the near future, cotton crop will gain popularity as a multipurpose crop in India. The commercialization of Bt cotton in 2002 and consequently the fast adoption of Bt cotton hybrids by cotton farmers have enhanced the cotton production in India. Presently, genetically modified (GM) cotton has occupied 21.0 million hectares (mha) that comprise 14% of the global area under GM cultivation. In the coming years, improved cotton hybrids, with stacked and multiple gene events for improved fiber quality, insect resistance, drought tolerance, and herbicide tolerance, would further significantly improve the cotton production in India. With the dramatic increase in commercialization of GM crops, there is an urgent need to develop cost-effective and robust GM detection methods for effective risk assessment and management, post release monitoring, and to solve the legal disputes. DNA-based GM diagnostics are most robust assays due to their high sensitivity, specificity, and stability of DNA molecule. PMID:23143480

  3. Detection methods and performance criteria for genetically modified organisms.

    PubMed

    Bertheau, Yves; Diolez, Annick; Kobilinsky, André; Magin, Kimberly

    2002-01-01

    Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness. Performance criteria should provide objective tools to accept or reject specific methods, to validate them, to ensure compatibility between validated methods, and be used on a routine basis to reject data outside an acceptable range of variability. When selecting a method of detection, it is also important to consider its applicability, its field of applications, and its limitations, by including factors such as its ability to detect the target analyte in a given matrix, the duration of the analyses, its cost effectiveness, and the necessary sample sizes for testing. Thus, the current GMO detection methods should be evaluated against a common set of performance criteria. PMID:12083279

  4. Stakeholders' Attitude to Genetically Modified Foods and Medicine

    PubMed Central

    Md Jahi, Jamaluddin; Md Nor, Abd Rahim

    2013-01-01

    Public acceptance of genetically modified (GM) foods has to be adequately addressed in order for their potential economic and social benefits to be realized. The objective of this paper is to assess the attitude of the Malaysian public toward GM foods (GM soybean and GM palm oil) and GM medicine (GM insulin). A survey was carried out using self-constructed multidimensional instrument measuring attitudes towards GM products. The respondents (n = 1017) were stratified according to stakeholders' groups in the Klang Valley region. Results of the survey show that the overall attitude of the Malaysian stakeholders towards GM products was cautious. Although they acknowledged the presence of moderate perceived benefits associated with GM products surveyed and were moderately encouraging of them, they were also moderately concerned about the risks and moral aspects of the three GM products as well as moderately accepting the risks. Attitudes towards GM products among the stakeholders were found to vary not according to the type of all GM applications but rather depend on the intricate relationships between the attitudinal factors and the type of gene transfers involved. Analyses of variance showed significant differences in the six dimensions of attitude towards GM products across stakeholders' groups. PMID:24381520

  5. Electrochemiluminescence-PCR detection of genetically modified organisms

    NASA Astrophysics Data System (ADS)

    Liu, Jinfeng; Xing, Da; Shen, Xingyan; Zhu, Debin

    2005-01-01

    The detection methods for genetically modified (GM) components in foods have been developed recently. But many of them are complicated and time-consuming; some of them need to use the carcinogenic substance, and can"t avoid false-positive results. In this study, an electrochemiluminescence polymerase chain reaction (ECL-PCR) method for detection GM tobaccos is proposed. The Cauliflower mosaic virus 35S (CaMV35S) promoter was amplified by PCR, Then hybridized with a Ru(bpy)32+ (TBR)-labeled and a biotinylated probe. The hybridization products were captured onto streptavidin-coated paramagnetic beads, and detected by measuring the electrochemiluminescence (ECL) signal of the TBR label. Whether the tobaccos contain GM components was discriminated by detecting the ECL signal of CaMV35S promoter. The experiment results show that the detection limit for CaMV35S promoter is 100 fmol, and the GM components can be clearly identified in GM tobaccos. The ECL-PCR method provide a new means in GMOs detection due to its safety, simplicity and high efficiency.

  6. Biofilm control with natural and genetically-modified phages.

    PubMed

    Motlagh, Amir Mohaghegh; Bhattacharjee, Ananda Shankar; Goel, Ramesh

    2016-04-01

    Bacteriophages, as the most dominant and diverse entities in the universe, have the potential to be one of the most promising therapeutic agents. The emergence of multidrug-resistant bacteria and the antibiotic crisis in the last few decades have resulted in a renewed interest in phage therapy. Furthermore, bacteriophages, with the capacity to rapidly infect and overcome bacterial resistance, have demonstrated a sustainable approach against bacterial pathogens-particularly in biofilm. Biofilm, as complex microbial communities located at interphases embedded in a matrix of bacterial extracellular polysaccharide substances (EPS), is involved in health issues such as infections associated with the use of biomaterials and chronic infections by multidrug resistant bacteria, as well as industrial issues such as biofilm formation on stainless steel surfaces in food industry and membrane biofouling in water and wastewater treatment processes. In this paper, the most recent studies on the potential of phage therapy using natural and genetically-modified lytic phages and their associated enzymes in fighting biofilm development in various fields including engineering, industry, and medical applications are reviewed. Phage-mediated prevention approaches as an indirect phage therapy strategy are also explored in this review. In addition, the limitations of these approaches and suggestions to overcome these constraints are discussed to enhance the efficiency of phage therapy process. Finally, future perspectives and directions for further research towards a better understanding of phage therapy to control biofilm are recommended. PMID:26931607

  7. Determinants of Public Attitudes to Genetically Modified Salmon

    PubMed Central

    Amin, Latifah; Azad, Md. Abul Kalam; Gausmian, Mohd Hanafy; Zulkifli, Faizah

    2014-01-01

    The objective of this paper is to assess the attitude of Malaysian stakeholders to genetically modified (GM) salmon and to identify the factors that influence their acceptance of GM salmon using a structural equation model. A survey was carried out on 434 representatives from various stakeholder groups in the Klang Valley region of Malaysia. Public attitude towards GM salmon was measured using self-developed questionnaires with seven-point Likert scales. The findings of this study have confirmed that public attitudes towards GM salmon is a complex issue and should be seen as a multi-faceted process. The most important direct predictors for the encouragement of GM salmon are the specific application-linked perceptions about religious acceptability of GM salmon followed by perceived risks and benefits, familiarity, and general promise of modern biotechnology. Encouragement of GM salmon also involves the interplay among other factors such as general concerns of biotechnology, threatening the natural order of things, the need for labeling, the need for patenting, confidence in regulation, and societal values. The research findings can serve as a database that will be useful for understanding the social construct of public attitude towards GM foods in a developing country. PMID:24489695

  8. New qualitative detection methods of genetically modified potatoes.

    PubMed

    Watanabe, Takahiro; Kuribara, Hideo; Mishima, Takashi; Kikuchi, Hiroyuki; Kodama, Takashi; Futo, Satoshi; Kasama, Kikuko; Toyota, Akie; Nouno, Masanori; Saita, Ayako; Takahashi, Kunihiko; Hino, Akihiro; Akiyama, Hiroshi; Maitani, Tamio; Kubo, Misao

    2004-09-01

    In Japan, 8 lines of genetically modified (GM) potato (2 lines of NewLeaf potato; NL, 3 lines of NewLeaf Plus potato; NLP, and 3 lines of NewLeaf Y potato; NLY) have already been authorized as safe for use in foods and feeds. We have developed polymerase chain reaction (PCR) methods for the qualitative detection of the GM potatoes for the screening and the identification of NL, NLP and NLY. The gene encoding uridine diphosphate (UDP)-glucose pyrophosphorylase (UGPase) was used as a taxon specific gene. We designed the primer pair to detect the cryIIIA genes as a screening method for GM potatoes because the gene should be inserted in all 8 lines of the GM potatoes. For identification of NL, NLP and NLY, we further designed three specific primer pairs for the different recombinant DNAs (r-DNA) specifically introduced into NL, NLP, or NLY. In addition, to identify the 3 lines of NLY that have been introduced with the same r-DNA, the three line-specific primer pairs for the border sequence between the r-DNA and genomic DNA of NLY 3 lines were designed. Six lines of GM potato used as the test material were specifically identified using the each primer pair under the same PCR condition. The detection limits of all the GM potatoes should be approximately 0.1%. Furthermore, the specificity and reproducibility of the methods were confirmed in a six-laboratory collaborative study. PMID:15340215

  9. Fungal community associated with genetically modified poplar during metal phytoremediation.

    PubMed

    Hur, Moonsuk; Lim, Young Woon; Yu, Jae Jeong; Cheon, Se Uk; Choi, Young Im; Yoon, Seok-Hwan; Park, Sang-Cheol; Kim, Dong-Il; Yi, Hana

    2012-12-01

    Due to the increasing demand for phytoremediation, many transgenic poplars have been developed to enhance the bioremediation of heavy metals. However, structural changes to indigenous fungal communities by genetically modified organisms (GMO) presents a major ecological issue, due to the important role of fungi for plant growth in natural environments. To evaluate the effect of GM plant use on environmental fungal soil communities, extensive sequencing-based community analysis was conducted, while controlling the influence of plant clonality, plant age, soil condition, and harvesting season. The rhizosphere soils of GM and wild type (WT) poplars at a range of growth stages were sampled together with unplanted, contaminated soil, and the fungal community structures were investigated by pyrosequencing the D1/D2 region of the 28S rRNA gene. The results show that the overall structure of the rhizosphere fungal community was not significantly influenced by GM poplars. However, the presence of GM specific taxa, and faster rate of community change during poplar growth, appeared to be characteristic of the GM plant-induced effects on soil-born fungal communities. The results of this study provide additional information about the potential effects of GM poplar trees aged 1.5-3 years, on the soil fungal community. PMID:23274976

  10. Aphid–parasitoid community structure on genetically modified wheat

    PubMed Central

    von Burg, Simone; van Veen, Frank J. F.; Álvarez-Alfageme, Fernando; Romeis, Jörg

    2011-01-01

    Since the introduction of genetically modified (GM) plants, one of the main concerns has been their potential effect on non-target insects. Many studies have looked at GM plant effects on single non-target herbivore species or on simple herbivore–natural enemy food chains. Agro-ecosystems, however, are characterized by numerous insect species which are involved in complex interactions, forming food webs. In this study, we looked at transgenic disease-resistant wheat (Triticum aestivum) and its effect on aphid–parasitoid food webs. We hypothesized that the GM of the wheat lines directly or indirectly affect aphids and that these effects cascade up to change the structure of the associated food webs. Over 2 years, we studied different experimental wheat lines under semi-field conditions. We constructed quantitative food webs to compare their properties on GM lines with the properties on corresponding non-transgenic controls. We found significant effects of the different wheat lines on insect community structure up to the fourth trophic level. However, the observed effects were inconsistent between study years and the variation between wheat varieties was as big as between GM plants and their controls. This suggests that the impact of our powdery mildew-resistant GM wheat plants on food web structure may be negligible and potential ecological effects on non-target insects limited. PMID:21247941

  11. Consumer perception of genetically modified organisms and sources of information.

    PubMed

    Wunderlich, Shahla; Gatto, Kelsey A

    2015-11-01

    Genetically modified organisms (GMOs) have been available for commercial purchase since the 1990s, allowing producers to increase crop yields through bioengineering that creates herbicide-resistant and insect-resistant varieties. However, consumer knowledge about GMOs has not increased at the same rate as the adoption of GMO crops. Consumers worldwide are displaying limited understanding, misconceptions, and even unfamiliarity with GMO food products. Many consumers report that they receive information about GMO food products from the media, Internet, and other news sources. These sources may be less reliable than scientific experts whom consumers trust more to present the facts. Although many in the United States support mandatory GMO labeling (similar to current European standards), consumer awareness of current GMO labeling is low. A distinction must also be made between GMO familiarity and scientific understanding, because those who are more familiar with it tend to be more resistant to bioengineering, whereas those with higher scientific knowledge scores tend to have less negative attitudes toward GMOs. This brings to question the relation between scientific literacy, sources of information, and overall consumer knowledge and perception of GMO foods. PMID:26567205

  12. Health Considerations Regarding Horizontal Transfer of Microbial Transgenes Present in Genetically Modified Crops

    PubMed Central

    Kleter, Gijs A.

    2005-01-01

    The potential effects of horizontal gene transfer on human health are an important item in the safety assessment of genetically modified organisms. Horizontal gene transfer from genetically modified crops to gut microflora most likely occurs with transgenes of microbial origin. The characteristics of microbial transgenes other than antibiotic-resistance genes in market-approved genetically modified crops are reviewed. These characteristics include the microbial source, natural function, function in genetically modified crops, natural prevalence, geographical distribution, similarity to other microbial genes, known horizontal transfer activity, selective conditions and environments for horizontally transferred genes, and potential contribution to pathogenicity and virulence in humans and animals. The assessment of this set of data for each of the microbial genes reviewed does not give rise to health concerns. We recommend including the above-mentioned items into the premarket safety assessment of genetically modified crops carrying transgenes other than those reviewed in the present study. PMID:16489267

  13. AN INTEGRATED MAP FOR MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Mapping Project (MMP) is focused on developing genetic, physical, and database resources for the maize genome. A key resource being developed by the MMP is a well-integrated genetic and physical map that will expedite the identification of DNA sequences underlying key traits that have been...

  14. Genetically Modified Organisms and the Future Global Nutrient Supply: Part of the Solution or a New Problem?

    PubMed

    Phillips, Peter W B

    2016-01-01

    For almost a generation now, scientists and policy makers have enthusiastically advanced genetically modified (GM) crops as a solution to both global food security and, specifically, the micronutrient needs of the hidden hungry. While genetic modification offers the prospect of overcoming technological barriers to food security, the gap between the vision and reality remains large. This chapter examines the impact of GM crops at three levels. Undoubtedly, at the micro level, bio-fortification offers a real opportunity to enhance the availability of micronutrients. However, the inexorable 'research sieve' ruthlessly culls most technical candidates in the agri-food system. GM bio-fortified foods, such as Golden RiceTM, remain only a promise. At the meso level, GM crops have generated benefits for both producers and consumers who have adopted GM crops, but given that the technology has been differentially applied to maize, the average diet for the food insecure has become somewhat less balanced. Finally, while GM crops have increased yields and the global food supply, these have come at the cost of more complex and costly trade and market systems, which impair access and availability. In essence, while biotechnology offers some tantalizing technological prospects, the difficulties of getting the corresponding benefits to the most needy have dampened some of the enthusiasm. PMID:27197734

  15. Stable Carbon Isotope Discrimination Is under Genetic Control in the C4 Species Maize with Several Genomic Regions Influencing Trait Expression1[W

    PubMed Central

    Gresset, Sebastian; Westermeier, Peter; Rademacher, Svenja; Ouzunova, Milena; Presterl, Thomas; Westhoff, Peter; Schön, Chris-Carolin

    2014-01-01

    In plants with C4 photosynthesis, physiological mechanisms underlying variation in stable carbon isotope discrimination (Δ13C) are largely unknown, and genetic components influencing Δ13C have not been described. We analyzed a maize (Zea mays) introgression library derived from two elite parents to investigate whether Δ13C is under genetic control in this C4 species. High-density genotyping with the Illumina MaizeSNP50 Bead Chip was used for a detailed structural characterization of 89 introgression lines. Phenotypic analyses were conducted in the field and in the greenhouse for kernel Δ13C as well as plant developmental and photosynthesis-related traits. Highly heritable significant genetic variation for Δ13C was detected under field and greenhouse conditions. For several introgression library lines, Δ13C values consistently differed from the recurrent parent within and across the two phenotyping platforms. Δ13C was significantly associated with 22 out of 164 analyzed genomic regions, indicating a complex genetic architecture of Δ13C. The five genomic regions with the largest effects were located on chromosomes 1, 2, 6, 7, and 9 and explained 55% of the phenotypic variation for Δ13C. Plant development stage had no effect on Δ13C expression, as phenotypic as well as genotypic correlations between Δ13C, flowering time, and plant height were not significant. To our knowledge, this is the first study demonstrating Δ13C to be under polygenic control in the C4 species maize. PMID:24280436

  16. Genetically modified and wild soybeans: an immunologic comparison.

    PubMed

    Yum, Hye-Yung; Lee, Soo-Young; Lee, Kyung-Eun; Sohn, Myung-Hyun; Kim, Kyu-Earn

    2005-01-01

    Most traits introduced into genetically engineered crops result from the expression of new proteins. As the first step toward assessing the allergenic potential of genetically modified organism (GMO) food, immunologic and physicochemical characterizations are needed. We prepared crude extract from GMO soybeans, wild soybeans, curd, and soy milk and then performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). After acidification with HCl, the samples were separated to globulin and whey. To evaluate changes in protein composition, either the samples were heated or pepsin was added. Polymerase chain reaction with primer encoding the 35S-promotor and the 3-enol-pyruvyl-shikimat-5-phosphat-synthase gene were performed, respectively, to detect the GMO component. SDS-PAGE results showed definite protein bands at 80 kDa in GMO soybean, 50 kDa in wild soybean, and a similar distribution of protein bands was noticed below 40 kDa. It was difficult to observe protein distribution because of modifications that occurred during processing in soybean-processed products. After heating, proteins of GMO and wild soybeans showed similar distributions and no distinct bands were detected at 50 and 80 kDa. Although SDS-PAGE analyses of raw GMO and wild soybeans differed, the same protein bands of 68, 37, and 20 kDa were observed in the globulin fraction after acidification. After adding pepsin, 20- and 68-kDa bands were found preserved in GMO and wild soybeans. The polymerase chain reaction procedures with primers specific to GMO soybeans showed that GMO soybeans and some curd samples included a GMO component. The skin test results of 49 patients showed 13 positive results to wild soybeans and 8 positive results to GMO soybeans. One patient had a positive skin test result to GMO soybeans only. Sera from nine patients with positive skin tests to the crude extract and a positive capsulated allergen product test to the soybean antigen were used for the immunoblotting of GMO and wild soybeans. GMO soybeans revealed a unique strong immunoglobulin E binding band at 25 kDa in some patients and wild soybeans showed a strong immunoglobulin E binding band at 30-36 kDa. To assess the allergenicity of GMO food, more research, including a selection of controlled sample materials and immunoassays of qualified sera, is needed. PMID:16119037

  17. Choosing a Genome Browser for a Model Organism Database (MOD): Surveying the Maize Community

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the maize genome sequencing is nearing its completion, the Maize Genetics and Genomics Database (MaizeGDB), the Model Organism Database for maize, integrated a genome browser to its already existing Web interface and database. The addition of the MaizeGDB Genome Browser to MaizeGDB will allow it ...

  18. Maize proteomics: an insight into the biology of an important cereal crop.

    PubMed

    Pechanova, Olga; Tak?, Tom; Samaj, Jozef; Pechan, Tibor

    2013-02-01

    Maize (Zea mays L.) is the most grown cereal crop in the world (839 million tons in 2012). According to its agro-economical importance, maize has received tremendous attention from research communities of academic, state, and industry origin. In this manuscript, we aspire to provide readers with the first comprehensive review of proteomics studies performed on maize within a 1987-2012 time period. The following topics are presented here: maize proteome profiling, developmental proteomics, response to abiotic and biotic stress, maize phosphoproteomics, tissue-specific wild-type versus mutant analyses, heterosis, seed viability, maize allergens, and safety assessment of genetically modified maize. Tissues, organelles, subcellular compartments, secretomes, methods, phenomena, and pertinent proteins were summarized and referenced in tables and figures to provide readers with expediently accessible information in the context of up-to-date achievements. This review illustrates maize proteomics as a firmly established research area with laboratories around the world diligently advancing our knowledge of diverse aspects of maize biology. PMID:23197376

  19. NeuroGeM, a knowledgebase of genetic modifiers in neurodegenerative diseases

    PubMed Central

    2013-01-01

    Background Neurodegenerative diseases (NDs) are characterized by the progressive loss of neurons in the human brain. Although the majority of NDs are sporadic, evidence is accumulating that they have a strong genetic component. Therefore, significant efforts have been made in recent years to not only identify disease-causing genes but also genes that modify the severity of NDs, so-called genetic modifiers. To date there exists no compendium that lists and cross-links genetic modifiers of different NDs. Description In order to address this need, we present NeuroGeM, the first comprehensive knowledgebase providing integrated information on genetic modifiers of nine different NDs in the model organisms D. melanogaster, C. elegans, and S. cerevisiae. NeuroGeM cross-links curated genetic modifier information from the different NDs and provides details on experimental conditions used for modifier identification, functional annotations, links to homologous proteins and color-coded protein-protein interaction networks to visualize modifier interactions. We demonstrate how this database can be used to generate new understanding through meta-analysis. For instance, we reveal that the Drosophila genes DnaJ-1, thread, Atx2, and mub are generic modifiers that affect multiple if not all NDs. Conclusion As the first compendium of genetic modifiers, NeuroGeM will assist experimental and computational scientists in their search for the pathophysiological mechanisms underlying NDs. http://chibi.ubc.ca/neurogem. PMID:24229347

  20. Attitudes of agricultural scientists in Indonesia towards genetically modified foods.

    PubMed

    Februhartanty, Judhiastuty; Widyastuti, Tri Nisa; Iswarawanti, Dwi Nastiti

    2007-01-01

    Conflicting arguments and partial truths on genetically modified (GM) foods have left confusion. Although studies of consumer acceptance of GM foods are numerous, the study of scientists is limited. Therefore, the main objective of this study was to assess the attitudes of scientists towards GM foods. The study was a cross sectional study. A total of 400 scientists (involved in at least one of teaching, research and consultancy) in the Bogor Agricultural Institute, Indonesia were selected randomly from its faculties of agriculture, veterinary, fishery, animal husbandry, forestry, agricultural technology, mathematics and science, and the post graduate department. Data collection was done by face-to-face interview using a structured questionnaire and self-administered questionnaire. The result showed that the majority (72.8%) of the respondents were favorably disposed towards GM foods, 14.8% were neutral, and only 12.5% were against them. The majority (78.3%) stated that they would try GM food if offered. Most (71%) reported that they were aware of the term "GM foods". Only half of the respondents felt that they had a basic understanding about GM foods. However, based on a knowledge test, 69.8% had a good knowledge score. Nearly 50% indicated that they were more exposed to news which supported GM foods. Over 90% said that there should be some form of labeling to distinguish food containing GM ingredients from non-GM foods. Attitudes were significantly associated with willingness to try GM foods if offered, restrictions on GM foods, and exposure to media reports about the pros and cons of GM foods. PMID:17468097

  1. Long term evaluation of field-released genetically modified rhizobia.

    PubMed

    Corich, Viviana; Giacomini, Alessio; Vendramin, Elena; Vian, Patrizia; Carlot, Milena; Concheri, Giuseppe; Polone, Elisa; Casella, Sergio; Nuti, Marco P; Squartini, Andrea

    2007-01-01

    This is the report of the first open field release of genetically modified microorganisms (GMMs) in Italy. It covers ten years of monitoring, and follows in-field GMM dynamics from strain release to disappearance below detection limits, as well as assessment of impact on resident microorganisms. The bacteria released belong to the nitrogen fixing legume endosymbiont Rhizobium leguminosarum bv. viciae, and were engineered with non-agronomically-proficient traits, in order to assess their behavior and fate without GMM-specific positive feedback from the plant. A DNA cassette containing mercury resistance and ss-galactosidase genes was introduced in either plasmid-borne or chromosomally integrated versions, in order to test the resulting strain stability. A synthetic promoter was used to drive the lacZ gene, conferring high catabolic activity to the GMM. Two different wild-type Rhizobium backgrounds were tested, comparing a non-indigenous vs. an indigenous, highly competitive strain. The latter had much greater persistence, since it was able to survive and establish at technically detectable levels for over four years after release. Selection factors, such as reiterated presence of the plant host, or lactose substrate supply, enhanced long-term survival to different extents. The lactose treatment showed that even a single trophic supplementation can surpass the benefits of symbiotic interaction for a period of several years. Concerning impact, the GMMs did not alter substantially the other soil community general microbiota. However, there were some significant differences in microbiota as a consequence of the Rhizobium inoculation. This effect was observed with either the WT or GMM, and was more evident in the release of the indigenous Rhizobium. Moreover, as the indigenous GMM had its parental, dominant wild-type in the same soil, it was possible to evaluate to what extent the GMM version could result in parent displacement ("self-impact"), and how much the two rhizobia would additively contribute to nodulation. PMID:18001684

  2. Genetic modifiers of MeCP2 function in Drosophila.

    PubMed

    Cukier, Holly N; Perez, Alma M; Collins, Ann L; Zhou, Zhaolan; Zoghbi, Huda Y; Botas, Juan

    2008-01-01

    The levels of methyl-CpG-binding protein 2 (MeCP2) are critical for normal post-natal development and function of the nervous system. Loss of function of MeCP2, a transcriptional regulator involved in chromatin remodeling, causes classic Rett syndrome (RTT) as well as other related conditions characterized by autism, learning disabilities, or mental retardation. Increased dosage of MeCP2 also leads to clinically similar neurological disorders and mental retardation. To identify molecular mechanisms capable of compensating for altered MeCP2 levels, we generated transgenic Drosophila overexpressing human MeCP2. We find that MeCP2 associates with chromatin and is phosphorylated at serine 423 in Drosophila, as is found in mammals. MeCP2 overexpression leads to anatomical (i.e., disorganized eyes, ectopic wing veins) and behavioral (i.e., motor dysfunction) abnormalities. We used a candidate gene approach to identify genes that are able to compensate for abnormal phenotypes caused by MeCP2 increased activity. These genetic modifiers include other chromatin remodeling genes (Additional sex combs, corto, osa, Sex combs on midleg, and trithorax), the kinase tricornered, the UBE3A target pebble, and Drosophila homologues of the MeCP2 physical interactors Sin3a, REST, and N-CoR. These findings demonstrate that anatomical and behavioral phenotypes caused by MeCP2 activity can be ameliorated by altering other factors that might be more amenable to manipulation than MeCP2 itself. PMID:18773074

  3. Clinical and laboratory investigation of allergy to genetically modified foods.

    PubMed Central

    Bernstein, Jonathan A; Bernstein, I Leonard; Bucchini, Luca; Goldman, Lynn R; Hamilton, Robert G; Lehrer, Samuel; Rubin, Carol; Sampson, Hugh A

    2003-01-01

    Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying. PMID:12826483

  4. Factors influencing stakeholders attitudes toward genetically modified aedes mosquito.

    PubMed

    Amin, Latifah; Hashim, Hasrizul

    2015-06-01

    Dengue fever is a debilitating and infectious disease that could be life-threatening. It is caused by the dengue virus which affects millions of people in the tropical area. Currently, there is no cure for the disease as there is no vaccine available. Thus, prevention of the vector population using conventional methods is by far the main strategy but has been found ineffective. A genetically modified (GM) mosquito is among the favoured alternatives to curb dengue fever in Malaysia. Past studies have shown that development and diffusion of gene technology products depends heavily upon public acceptance. The purpose of this study is to identify the relevant factors influencing stakeholders' attitudes toward the GM Aedes mosquito and to analyse the relationships between all the factors using the structural equation model. A survey was carried out on 509 respondents from various stakeholder groups in the Klang Valley region of Malaysia. Results of the survey have confirmed that public perception towards complex issues such as gene technology should be seen as a multi-faceted process. The perceived benefit-perceived risk balance is very important in determining the most predominant predictor of attitudes toward a GM mosquito. In this study the stakeholders perceived the benefit of the GM mosquito as outweighing its risk, translating perceived benefit as the most important direct predictor of attitudes toward the GM mosquito. Trust in key players has a direct influence on attitudes toward the GM mosquito while moral concern exhibited an indirect influence through perceived benefits. Other factors such as attitudes toward technology and nature were also indirect predictors of attitudes toward the GM mosquito while religiosity and engagement did not exhibited any significant roles. The research findings serve as a useful database to understand public acceptance and the social construct of public attitudes towards the GM mosquito to combat dengue. PMID:24906652

  5. Recombination in maize is stable, predictable, and associated with genetic load: a joint study of the US and Chinese maize NAM populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among the fundamental evolutionary forces, recombination arguably has the largest impact on the practical work of plant breeders. Varying over 1,000-fold across the maize genome, the local meiotic recombination rate limits the resolving power of quantitative trait mapping and the precision of favora...

  6. Romanian Maize (Zea mays) Inbred Lines as a Source of Genetic Diversity in SE Europe, and Their Potential in Future Breeding Efforts

    PubMed Central

    Haș, Voichița; Haș, Ioan; Miclăuș, Mihai

    2013-01-01

    Maize has always been under constant human selection ever since it had been domesticated. Intensive breeding programs that resulted in the massive use of hybrids nowadays have started in the 60s. That brought significant yield increases but reduced the genetic diversity at the same time. Consequently, breeders and researchers alike turned their attention to national germplasm collections established decades ago in many countries, as they may hold allelic variations that could prove useful for future improvements. These collections are mainly composed of inbred lines originating from well-adapted local open pollinated varieties. However, there is an overall lack of data in the literature about the genetic diversity of maize in SE Europe, and its potential for future breeding efforts. There are no data, whatsoever, on the nutritional quality of the grain, primarily dictated by the zein proteins. We therefore sought to use the Romanian maize germplasm as an entry point in understanding the molecular make-up of maize in this part of Europe. By using 80 SSR markers, evenly spread throughout the genome, on 82 inbred lines from various parts of the country, we were able to decipher population structure and the existing relationships between those and the eight international standards used, including the reference sequenced genome B73. Corroborating molecular data with a standardized morphological, physiological, and biochemical characterization of all 90 inbred lines, this is the first comprehensive such study on the existing SE European maize germplasm. The inbred lines we present here are an important addition to the ever-shrinking gene pool that the breeding programs are faced-with, because of the allelic richness they hold. They may serve as parental lines in crosses that will lead to new hybrids, characterized by a high level of heterosis, nationwide and beyond, due to their existing relationship with the international germplasm. PMID:24392016

  7. Preventing the spread of malaria and dengue fever using genetically modified mosquitoes.

    PubMed

    James, Anthony A

    2007-01-01

    In this candid interview, Anthony A. James explains how mosquito genetics can be exploited to control malaria and dengue transmission. Population replacement strategy, the idea that transgenic mosquitoes can be released into the wild to control disease transmission, is introduced, as well as the concept of genetic drive and the design criterion for an effective genetic drive system. The ethical considerations of releasing genetically-modified organisms into the wild are also discussed. PMID:18979028

  8. Recent advances in genome editing and creation of genetically modified pigs.

    PubMed

    Butler, James R; Ladowski, Joseph M; Martens, Gregory R; Tector, Matthew; Tector, A Joseph

    2015-11-01

    The field of xenotransplantation is benefiting greatly from recent advances in genetic engineering. The efficiency and pace with which new model animals are being created has dramatically sped progress towards clinical relevance. Endonuclease-driven genome editing now allows for the efficient generation of targeted genetic alterations. Herein we review the available methods of genetic engineering that have been successfully employed to create genetically modified pigs. PMID:26231992

  9. Consumer reaction to information on the labels of genetically modified food

    PubMed Central

    Sebastian-Ponce, Miren Itxaso; Sanz-Valero, Javier; Wanden-Berghe, Carmina

    2014-01-01

    OBJECTIVE To analyze consumer opinion on genetically modified foods and the information included on the label. METHODS A systematic review of the scientific literature on genetically modified food labeling was conducted consulting bibliographic databases (Medline – via PubMed –, EMBASE, ISI-Web of knowledge, Cochrane Library Plus, FSTA, LILACS, CINAHL and AGRICOLA) using the descriptors “organisms, genetically modified” and “food labeling”. The search covered the first available date, up to June 2012, selecting relevant articles written in English, Portuguese or Spanish. RESULTS Forty articles were selected after applying the inclusion and exclusion criteria. All of them should have conducted a population-based intervention focused on consumer awareness of genetically modified foods and their need or not, to include this on the label. The consumers expressed a preference for non-genetically modified products, and added that they were prepared to pay more for this but, ultimately, the product bought was that with the best price, in a market which welcomes new technologies. In 18 of the articles, the population was in favor of obligatory labelling, and in six, in favor of this being voluntary; seven studies showed the consumer knew little about genetically modified food, and in three, the population underestimated the quantity they consumed. Price was an influencing factor in all cases. CONCLUSIONS Label should be homogeneous and clarify the degree of tolerance of genetically modified products in humans, in comparison with those non-genetically modified. Label should also present the content or not of genetically modified products and how these commodities are produced and should be accompanied by the certifying entity and contact information. Consumers express their preference for non-genetically modifiedproducts and they even notice that they are willing to pay more for it, but eventually they buy the item with the best price, in a market that welcomes new technologies. PMID:24789648

  10. Single-Kernel Ionomic Profiles Are Highly Heritable Indicators of Genetic and Environmental Influences on Elemental Accumulation in Maize Grain (Zea mays)

    PubMed Central

    Baxter, Ivan R.; Ziegler, Gregory; Lahner, Brett; Mickelbart, Michael V.; Foley, Rachel; Danku, John; Armstrong, Paul; Salt, David E.; Hoekenga, Owen A.

    2014-01-01

    The ionome, or elemental profile, of a maize kernel can be viewed in at least two distinct ways. First, the collection of elements within the kernel are food and feed for people and animals. Second, the ionome of the kernel represents a developmental end point that can summarize the life history of a plant, combining genetic programs and environmental interactions. We assert that single-kernel-based phenotyping of the ionome is an effective method of analysis, as it represents a reasonable compromise between precision, efficiency, and power. Here, we evaluate potential pitfalls of this sampling strategy using several field-grown maize sample sets. We demonstrate that there is enough genetically determined diversity in accumulation of many of the elements assayed to overcome potential artifacts. Further, we demonstrate that environmental signals are detectable through their influence on the kernel ionome. We conclude that using single kernels as the sampling unit is a valid approach for understanding genetic and environmental effects on the maize kernel ionome. PMID:24489944

  11. Avoiding genetically modified foods in GMO Ground Zero: A reflective self-narrative.

    PubMed

    Edwards, Sachi

    2015-05-01

    I engage in a reflective self-narrative of my experience attempting to maintain a diet free of genetically modified organisms. Social tension over the genetically modified organism industry in Hawai'i, United States, has led to public debates over jobs and social identities. Drawing on local media sources, grassroots organizations, and blog posts, I describe the way this tension has shaped my experience with food, eating, and being with others as a genetically modified organism avoider. I utilize discursive positioning to make sense of my experiences by locating them within the ongoing public conversations that give structure to the daily lives of Hawai'i's residents. PMID:25903238

  12. Genetic Perspectives on Loss of Diversity in Elite Maize Breeding Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection and genetic drift are two processes that are very well understood if treated separately, but very poorly understood when acting in concert. As a result, existing quantitative genetic theory does not provide any good methods for developing optimal strategies for maintaining sustainable sel...

  13. Molecular toolbox for the identification of unknown genetically modified organisms.

    PubMed

    Ruttink, Tom; Demeyer, Rolinde; Van Gulck, Elke; Van Droogenbroeck, Bart; Querci, Maddalena; Taverniers, Isabel; De Loose, Marc

    2010-03-01

    Competent laboratories monitor genetically modified organisms (GMOs) and products derived thereof in the food and feed chain in the framework of labeling and traceability legislation. In addition, screening is performed to detect the unauthorized presence of GMOs including asynchronously authorized GMOs or GMOs that are not officially registered for commercialization (unknown GMOs). Currently, unauthorized or unknown events are detected by screening blind samples for commonly used transgenic elements, such as p35S or t-nos. If (1) positive detection of such screening elements shows the presence of transgenic material and (2) all known GMOs are tested by event-specific methods but are not detected, then the presence of an unknown GMO is inferred. However, such evidence is indirect because it is based on negative observations and inconclusive because the procedure does not identify the causative event per se. In addition, detection of unknown events is hampered in products that also contain known authorized events. Here, we outline alternative approaches for analytical detection and GMO identification and develop new methods to complement the existing routine screening procedure. We developed a fluorescent anchor-polymerase chain reaction (PCR) method for the identification of the sequences flanking the p35S and t-nos screening elements. Thus, anchor-PCR fingerprinting allows the detection of unique discriminative signals per event. In addition, we established a collection of in silico calculated fingerprints of known events to support interpretation of experimentally generated anchor-PCR GM fingerprints of blind samples. Here, we first describe the molecular characterization of a novel GMO, which expresses recombinant human intrinsic factor in Arabidopsis thaliana. Next, we purposefully treated the novel GMO as a blind sample to simulate how the new methods lead to the molecular identification of a novel unknown event without prior knowledge of its transgene sequence. The results demonstrate that the new methods complement routine screening procedures by providing direct conclusive evidence and may also be useful to resolve masking of unknown events by known events. PMID:19937431

  14. The iojap gene in maize

    SciTech Connect

    Martienssen, Robert

    2001-12-01

    The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

  15. Unravelling modifiers of breast and ovarian cancer risk for BRCA1 and BRCA2 mutation carriers: update on genetic modifiers.

    PubMed

    Barnes, D R; Antoniou, A C

    2012-04-01

    Pathogenic mutations in the tumour suppressor genes BRCA1 and BRCA2 confer increased risks for breast and ovarian cancer and account for approximately 15% of the excess familial risk of breast cancer amongst first-degree relatives of patients with breast cancer. There is considerable evidence indicating that these risks vary by other genetic and environmental factors clustering in families. In the past few years, based on the availability of genome-wide association data and samples from large collaborative studies, several common alleles have been found to modify breast or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. These common alleles explain a small proportion of the genetic variability in breast or ovarian cancer risk for mutation carriers, suggesting more modifiers remain to be identified. We review the so far identified genetic modifiers of breast and ovarian cancer risk and consider the implications for risk prediction. BRCA1 and BRCA2 mutation carriers could be some of the first to benefit from clinical applications of common variants identified through genome-wide association studies. However, to be able to provide more individualized risk estimates, it will be important to understand how the associations vary with different tumour characteristics and their interactions with other genetic and environmental modifiers. PMID:22443199

  16. Multiple organ histopathological changes in broiler chickens fed on genetically modified organism.

    PubMed

    Cîrnatu, Daniela; Jompan, A; Sin, Anca Ileana; Zugravu, Cornelia Aurelia

    2011-01-01

    Diet can influence the structural characteristics of internal organs. An experiment involving 130 meat broilers was conducted during 42 days (life term for a meat broiler) to study the effect of feed with protein from genetically modified soy. The 1-day-old birds were randomly allocated to five study groups, fed with soy, sunflower, wheat, fish flour, PC starter. In the diet of each group, an amount of protein from soy was replaced with genetically modified soy (I - 0%, II - 25%, III - 50%, IV - 75%, V - 100% protein from genetically modified soy). The level of protein in soy, either modified, or non-modified, was the same. Organs and carcass weights were measured at about 42 days of age of the birds and histopathology exams were performed during May-June 2009. No statistically significant differences were observed in mortality, growth performance variables or carcass and organ yields between broilers consuming diets produced with genetically modified soybean fractions and those consuming diets produced with near-isoline control soybean fractions. Inflammatory and degenerative liver lesions, muscle hypertrophy, hemorrhagic necrosis of bursa, kidney focal tubular necrosis, necrosis and superficial ulceration of bowel and pancreatic dystrophies were found in tissues from broilers fed on protein from genetically modified soy. Different types of lesions found in our study might be due to other causes (parasites, viral) superimposed but their presence exclusively in groups fed with modified soy raises some serious questions about the consequences of use of this type of feed. PMID:21424096

  17. Comparison of whole-genome prediction models for traits with contrasting genetic architecture in a diversity panel of maize inbred lines

    PubMed Central

    2012-01-01

    Background There is increasing empirical evidence that whole-genome prediction (WGP) is a powerful tool for predicting line and hybrid performance in maize. However, there is a lack of knowledge about the sensitivity of WGP models towards the genetic architecture of the trait. Whereas previous studies exclusively focused on highly polygenic traits, important agronomic traits such as disease resistances, nutrifunctional or climate adaptational traits have a genetic architecture which is either much less complex or unknown. For such cases, information about model robustness and guidelines for model selection are lacking. Here, we compared five WGP models with different assumptions about the distribution of the underlying genetic effects. As contrasting model traits, we chose three highly polygenic agronomic traits and three metabolites each with a major QTL explaining 22 to 30% of the genetic variance in a panel of 289 diverse maize inbred lines genotyped with 56,110 SNPs. Results We found the five WGP models to be remarkable robust towards trait architecture with the largest differences in prediction accuracies ranging between 0.05 and 0.14 for the same trait, most likely as the result of the high level of linkage disequilibrium prevailing in elite maize germplasm. Whereas RR-BLUP performed best for the agronomic traits, it was inferior to LASSO or elastic net for the three metabolites. We found the approach of genome partitioning of genetic variance, first applied in human genetics, as useful in guiding the breeder which model to choose, if prior knowledge of the trait architecture is lacking. Conclusions Our results suggest that in diverse germplasm of elite maize inbred lines with a high level of LD, WGP models differ only slightly in their accuracies, irrespective of the number and effects of QTL found in previous linkage or association mapping studies. However, small gains in prediction accuracies can be achieved if the WGP model is selected according to the genetic architecture of the trait. If the trait architecture is unknown e.g. for novel traits which only recently received attention in breeding, we suggest to inspect the distribution of the genetic variance explained by each chromosome for guiding model selection in WGP. PMID:22947126

  18. Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus.

    PubMed

    Atehnkeng, Joseph; Donner, Matthias; Ojiambo, Peter S; Ikotun, Babatunde; Augusto, Joao; Cotty, Peter J; Bandyopadhyay, Ranajit

    2016-01-01

    Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security and farmers' income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the effectiveness of atoxigenic isolates in mitigating aflatoxin contamination. However, such information has not been used to facilitate selection and deployment of atoxigenic isolates. A total of 35 isolates of A. flavus isolated from maize samples collected from three agro-ecological zones of Nigeria were used in this study. Ecophysiological characteristics, distribution and genetic diversity of the isolates were determined to identify vegetative compatibility groups (VCGs). The generated data were used to inform selection and deployment of native atoxigenic isolates to mitigate aflatoxin contamination in maize. In co-inoculation with toxigenic isolates, atoxigenic isolates reduced aflatoxin contamination in grain by > 96%. A total of 25 VCGs were inferred from the collected isolates based on complementation tests involving nitrate non-utilizing (nit(-) ) mutants. To determine genetic diversity and distribution of VCGs across agro-ecological zones, 832 nit(-) mutants from 52 locations in 11 administrative districts were paired with one self-complementary nitrate auxotroph tester-pair for each VCG. Atoxigenic VCGs accounted for 81.1% of the 153 positive complementations recorded. Genetic diversity of VCGs was highest in the derived savannah agro-ecological zone (H = 2.61) compared with the southern Guinea savannah (H = 1.90) and northern Guinea savannah (H = 0.94) zones. Genetic richness (H = 2.60) and evenness (E5  = 0.96) of VCGs were high across all agro-ecological zones. Ten VCGs (40%) had members restricted to the original location of isolation, whereas 15 VCGs (60%) had members located between the original source of isolation and a distance > 400 km away. The present study identified widely distributed VCGs in Nigeria such as AV0222, AV3279, AV3304 and AV16127, whose atoxigenic members can be deployed for a region-wide biocontrol of toxigenic isolates to reduce aflatoxin contamination in maize. PMID:26503309

  19. Genetic studies on cytoplasmic male sterility in maize. Progress report, April 15, 1990--April 14, 1992

    SciTech Connect

    Laughnan, J.R.

    1992-05-01

    Our research concerns the basic mechanisms of cytoplasmic male sterility (CMS) and fertility restoration in maize. The molecular determination of CMS is in the DNA of the mitochondria (mtDNA) but specific nuclear restorer-of-fertility (Rf) genes can overrule the male-sterile effect of the cytoplasm. Our approach to the study of the Rf genes is threefold. We are attempting to tag the cms-S Rf genes and the cms-T Rf2 gene with controlling elements (CEs). Since we have identified a number of spontaneous Rf genes for cms-S and have demonstrated that they are themselves transposable, we are also searching for cases in which an Rf gene is inserted into a wild-type gene. The other aspect of our research involves the nuclear control over the organization of the mitochondrial genome. We found that the changes in mtDNA organization upon cytoplasmic reversion to fertility were characteristic of the nuclear background in which the reversion event occurred. We have investigated whether these differences are a reflection of differences in the organization of the mtDNA genome before reversion.

  20. [Progress on biosafety assessment of marker genes in genetically modified foods].

    PubMed

    Yang, Lichen; Yang, Xiaoguang

    2003-05-01

    Marker genes are useful in facilitating the detection of genetically modified organisms(GMO). These genes play an important role during the early identification stage of GMO development, but they exist in the mature genetically modified crops. So the safety assessment of these genes could not be neglected. In this paper, all the study on the biosafety assessment of marker genes were reviewed, their possible hazards and risks were appraised, and the marker genes proved safe were list too. GMO Labeling the is one important regulations for the development of genetically modified foods in the market. The accurate detecting techniques for GMO are the basis for setting up labeling regulation. In addition, some methods used to remove marker genes in genetically modified foods were introduced in the paper, which can eliminate their biosafety concern thoroughly. PMID:12914289

  1. USE OF MODELING APPROACHES TO UNDERSTAND POTENTIAL IMPACTS OF GENETICALLY MODIFIED PLANTS ON PLANT COMMUNITIES

    EPA Science Inventory

    Model development is of interest to ecologists, regulators and developers, since it may assist theoretical understanding, decision making in experimental design, product development and risk assessment. In order to predict the potential impacts of genetically modified (GM) plants...

  2. THE GENETIC BASIS OF C-GLYCOSYL FLAVONE B-RING MODIFICATION IN MAIZE (ZEA MAYS L.) SILKS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to corn earworm (Helicoverpa zea Boddie) has been attributed to high concentrations of C-glycosyl flavones and chlorogenic acid in maize (Zea mays L.) silks. The most common C-glycosyl flavones isolated from maize silks are maysin, apimaysin, and methoxymaysin, which are distinguished by ...

  3. Genetic relationships and structure among open pollinated maize varieties adapted to eastern and southern Africa using microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Maize and Wheat Improvement Center (CIMMYT), in collaboration with the national agricultural systems (NARS) in sub-Saharan Africa (SSA), have developed various stress-tolerant and more nutritious open-pollinated varieties (OPVs) of maize that are suitable for smallholder farmers’ g...

  4. Genome-wide association study dissects the genetic architecture of oil biosynthesis and accumulation in maize kernel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Genome Wide Association Study (GWAS) on a population of 368 maize inbreds with 1.06 million SNPs was performed and identified 74 highly significantly associated genes influencing maize kernel oil content and fatty acid composition. To validate these findings, three biparental linkage mapping popul...

  5. ZmCCT and the genetic basis of day-length adaptation underlying the postdomestication spread of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teosinte, the progenitor of maize, is restricted to tropical environments in Mexico and Central America. The pre-Columbian spread of maize from its center of origin in tropical Southern Mexico to the higher latitudes of the Americas required post-domestication selection for adaptation to longer dayl...

  6. Mutation Scanning in a Single and a Stacked Genetically Modified (GM) Event by Real-Time PCR and High Resolution Melting (HRM) Analysis

    PubMed Central

    Ben Ali, Sina-Elisabeth; Madi, Zita Erika; Hochegger, Rupert; Quist, David; Prewein, Bernhard; Haslberger, Alexander G.; Brandes, Christian

    2014-01-01

    Genetic mutations must be avoided during the production and use of seeds. In the European Union (EU), Directive 2001/18/EC requires any DNA construct introduced via transformation to be stable. Establishing genetic stability is critical for the approval of genetically modified organisms (GMOs). In this study, genetic stability of two GMOs was examined using high resolution melting (HRM) analysis and real-time polymerase chain reaction (PCR) employing Scorpion primers for amplification. The genetic variability of the transgenic insert and that of the flanking regions in a single oilseed rape variety (GT73) and a stacked maize (MON88017 × MON810) was studied. The GT73 and the 5' region of MON810 showed no instabilities in the examined regions. However; two out of 100 analyzed samples carried a heterozygous point mutation in the 3' region of MON810 in the stacked variety. These results were verified by direct sequencing of the amplified PCR products as well as by sequencing of cloned PCR fragments. The occurrence of the mutation suggests that the 5' region is more suitable than the 3' region for the quantification of MON810. The identification of the single nucleotide polymorphism (SNP) in a stacked event is in contrast to the results of earlier studies of the same MON810 region in a single event where no DNA polymorphism was found. PMID:25365178

  7. Mutation scanning in a single and a stacked genetically modified (GM) event by real-time PCR and high resolution melting (HRM) analysis.

    PubMed

    Ben Ali, Sina-Elisabeth; Madi, Zita Erika; Hochegger, Rupert; Quist, David; Prewein, Bernhard; Haslberger, Alexander G; Brandes, Christian

    2014-01-01

    Genetic mutations must be avoided during the production and use of seeds. In the European Union (EU), Directive 2001/18/EC requires any DNA construct introduced via transformation to be stable. Establishing genetic stability is critical for the approval of genetically modified organisms (GMOs). In this study, genetic stability of two GMOs was examined using high resolution melting (HRM) analysis and real-time polymerase chain reaction (PCR) employing Scorpion primers for amplification. The genetic variability of the transgenic insert and that of the flanking regions in a single oilseed rape variety (GT73) and a stacked maize (MON88017×MON810) was studied. The GT73 and the 5' region of MON810 showed no instabilities in the examined regions. However; two out of 100 analyzed samples carried a heterozygous point mutation in the 3' region of MON810 in the stacked variety. These results were verified by direct sequencing of the amplified PCR products as well as by sequencing of cloned PCR fragments. The occurrence of the mutation suggests that the 5' region is more suitable than the 3' region for the quantification of MON810. The identification of the single nucleotide polymorphism (SNP) in a stacked event is in contrast to the results of earlier studies of the same MON810 region in a single event where no DNA polymorphism was found. PMID:25365178

  8. A method to search for optimal field allocations of transgenic maize in the context of co-existence.

    PubMed

    Devos, Yann; Cougnon, Mathias; Thas, Olivier; Reheul, Dirk

    2008-01-01

    Spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm measure to keep the adventitious presence of GM material in the harvest of neighboring fields due to cross-fertilizations below the European labeling threshold of 0.9%. However, the implementation of mandatory and rigid isolation perimeters can affect the farmers' freedom of choice to grow GM maize on their fields if neighboring farmers do not concur with their respective cropping intentions and crop plans. To minimize the presence of non-GM maize within isolation perimeters implemented around GM maize fields, a method was developed for optimally allocating GM maize to a particular set of fields. Using a Geographic Information System dataset and Monte Carlo analyses, three scenarios were tested in a maize cultivation area with a low maize share in Flanders (Belgium). It was assumed that some farmers would act in collaboration by sharing the allocation of all their arable land for the cultivation of GM maize. From the large number of possible allocations of GM maize to any field of the shared pool of arable land, the best field combinations were selected. Compared to a random allocation of GM maize, the best field combinations made it possible to reduce spatial co-existence problems, since at least two times less non-GM maize fields and their corresponding farmers occurred within the implemented isolation perimeters. In the selected field sets, the mean field size was always larger than the mean field size of the common pool of arable land. These preliminary data confirm that the optimal allocation of GM maize over the landscape might theoretically be a valuable option to facilitate the implementation of rigid isolation perimeters imposed by law. PMID:18549771

  9. Development of sampling approaches for the determination of the presence of genetically modified organisms at the field level.

    PubMed

    Sustar-Vozlic, Jelka; Rostohar, Katja; Blejec, Andrej; Kozjak, Petra; Cergan, Zoran; Meglic, Vladimir

    2010-03-01

    In order to comply with the European Union regulatory threshold for the adventitious presence of genetically modified organisms (GMOs) in food and feed, it is important to trace GMOs from the field. Appropriate sampling methods are needed to accurately predict the presence of GMOs at the field level. A 2-year field experiment with two maize varieties differing in kernel colour was conducted in Slovenia. Based on the results of data mining analyses and modelling, it was concluded that spatial relations between the donor and receptor field were the most important factors influencing the distribution of outcrossing rate (OCR) in the field. The approach for estimation fitting function parameters in the receptor (non-GM) field at two distances from the donor (GM) field (10 and 25 m) for estimation of the OCR (GMO content) in the whole receptor field was developed. Different sampling schemes were tested; a systematic random scheme in rows was proposed to be applied for sampling at the two distances for the estimation of fitting function parameters for determination of OCR. The sampling approach had already been validated with some other OCR data and was practically applied in the 2009 harvest in Poland. The developed approach can be used for determination of the GMO presence at the field level and for making appropriate labelling decisions. The importance of this approach lies in its possibility to also address other threshold levels beside the currently prescribed labelling threshold of 0.9% for food and feed. PMID:20069281

  10. A rapid method for detection of genetically modified organisms based on magnetic separation and surface-enhanced Raman scattering.

    PubMed

    Guven, Burcu; Boyacı, İsmail Hakkı; Tamer, Ugur; Çalık, Pınar

    2012-01-01

    In this study, a new method combining magnetic separation (MS) and surface-enhanced Raman scattering (SERS) was developed to detect genetically modified organisms (GMOs). An oligonucleotide probe which is specific for 35 S DNA target was immobilized onto gold coated magnetic nanospheres to form oligonucleotide-coated nanoparticles. A self assembled monolayer was formed on gold nanorods using 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) and the second probe of the 35 S DNA target was immobilized on the activated nanorod surfaces. Probes on the nanoparticles were hybridized with the target oligonucleotide. Optimization parameters for hybridization were investigated by high performance liquid chromatography. Optimum hybridization parameters were determined as: 4 μM probe concentration, 20 min immobilization time, 30 min hybridization time, 55 °C hybridization temperature, 750 mM buffer salt concentration and pH: 7.4. Quantification of the target concentration was performed via SERS spectra of DTNB on the nanorods. The correlation between the target concentration and the SERS signal was found to be linear within the range of 25-100 nM. The analyses were performed with only one hybridization step in 40 min. Real sample analysis was conducted using Bt-176 maize sample. The results showed that the developed MS-SERS assay is capable of detecting GMOs in a rapid and selective manner. PMID:22049365

  11. Assessment of DNA degradation induced by thermal and UV radiation processing: implications for quantification of genetically modified organisms.

    PubMed

    Ballari, Rajashekhar V; Martin, Asha

    2013-12-01

    DNA quality is an important parameter for the detection and quantification of genetically modified organisms (GMO's) using the polymerase chain reaction (PCR). Food processing leads to degradation of DNA, which may impair GMO detection and quantification. This study evaluated the effect of various processing treatments such as heating, baking, microwaving, autoclaving and ultraviolet (UV) irradiation on the relative transgenic content of MON 810 maize using pRSETMON-02, a dual target plasmid as a model system. Amongst all the processing treatments examined, autoclaving and UV irradiation resulted in the least recovery of the transgenic (CaMV 35S promoter) and taxon-specific (zein) target DNA sequences. Although a profound impact on DNA degradation was seen during the processing, DNA could still be reliably quantified by Real-time PCR. The measured mean DNA copy number ratios of the processed samples were in agreement with the expected values. Our study confirms the premise that the final analytical value assigned to a particular sample is independent of the degree of DNA degradation since the transgenic and the taxon-specific target sequences possessing approximately similar lengths degrade in parallel. The results of our study demonstrate that food processing does not alter the relative quantification of the transgenic content provided the quantitative assays target shorter amplicons and the difference in the amplicon size between the transgenic and taxon-specific genes is minimal. PMID:23870938

  12. [Genetically modified plants and food safety. State of the art and discussion in the European Union].

    PubMed

    Schauzu, M

    2004-09-01

    Placing genetically modified (GM) plants and derived products on the European Union's (EU) market has been regulated by a Community Directive since 1990. This directive was complemented by a regulation specific for genetically modified and other novel foods in 1997. Specific labelling requirements have been applicable for GM foods since 1998. The law requires a pre-market safety assessment for which criteria have been elaborated and continuously adapted in accordance with the state of the art by national and international bodies and organisations. Consequently, only genetically modified products that have been demonstrated to be as safe as their conventional counterparts can be commercialized. However, the poor acceptance of genetically modified foods has led to a de facto moratorium since 1998. It is based on the lack of a qualified majority of EU member states necessary for authorization to place genetically modified plants and derived foods on the market. New Community Regulations are intended to end this moratorium by providing a harmonized and transparent safety assessment, a centralised authorization procedure, extended labelling provisions and a traceability system for genetically modified organisms (GMO) and derived food and feed. PMID:15378169

  13. Detection and traceability of genetically modified organisms in the food production chain.

    PubMed

    Miraglia, M; Berdal, K G; Brera, C; Corbisier, P; Holst-Jensen, A; Kok, E J; Marvin, H J P; Schimmel, H; Rentsch, J; van Rie, J P P F; Zagon, J

    2004-07-01

    Both labelling and traceability of genetically modified organisms are current issues that are considered in trade and regulation. Currently, labelling of genetically modified foods containing detectable transgenic material is required by EU legislation. A proposed package of legislation would extend this labelling to foods without any traces of transgenics. These new legislations would also impose labelling and a traceability system based on documentation throughout the food and feed manufacture system. The regulatory issues of risk analysis and labelling are currently harmonised by Codex Alimentarius. The implementation and maintenance of the regulations necessitates sampling protocols and analytical methodologies that allow for accurate determination of the content of genetically modified organisms within a food and feed sample. Current methodologies for the analysis of genetically modified organisms are focused on either one of two targets, the transgenic DNA inserted- or the novel protein(s) expressed- in a genetically modified product. For most DNA-based detection methods, the polymerase chain reaction is employed. Items that need consideration in the use of DNA-based detection methods include the specificity, sensitivity, matrix effects, internal reference DNA, availability of external reference materials, hemizygosity versus homozygosity, extrachromosomal DNA, and international harmonisation. For most protein-based methods, enzyme-linked immunosorbent assays with antibodies binding the novel protein are employed. Consideration should be given to the selection of the antigen bound by the antibody, accuracy, validation, and matrix effects. Currently, validation of detection methods for analysis of genetically modified organisms is taking place. In addition, new methodologies are developed, including the use of microarrays, mass spectrometry, and surface plasmon resonance. Challenges for GMO detection include the detection of transgenic material in materials with varying chromosome numbers. The existing and proposed regulatory EU requirements for traceability of genetically modified products fit within a broader tendency towards traceability of foods in general and, commercially, towards products that can be distinguished from each other. Traceability systems document the history of a product and may serve the purpose of both marketing and health protection. In this framework, segregation and identity preservation systems allow for the separation of genetically modified and non-modified products from "farm to fork". Implementation of these systems comes with specific technical requirements for each particular step of the food processing chain. In addition, the feasibility of traceability systems depends on a number of factors, including unique identifiers for each genetically modified product, detection methods, permissible levels of contamination, and financial costs. In conclusion, progress has been achieved in the field of sampling, detection, and traceability of genetically modified products, while some issues remain to be solved. For success, much will depend on the threshold level for adventitious contamination set by legislation. PMID:15123385

  14. MaizeGDB Becomes Sequence-centric

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the maize research community’s central repository for genetic and genomic information about the crop plant and research model Zea mays ssp. mays. The MaizeGDB team endeavors to meet research needs as they evolve based on researcher feedback and guidance. Recent work has focused on bett...

  15. MaizeGDB: New tools and resource

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB, the USDA-ARS genetics and genomics database, is a highly curated, community-oriented informatics service to researchers focused on the crop plant and model organism Zea mays. MaizeGDB facilitates maize research by curating, integrating, and maintaining a database that serves as the central...

  16. MaizeGDB's New Genome Browser Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. Based upon the 2006 MaizeGDB Working Group Report (available at http://www.maizegdb.org/working_group.php) and the Allerton Report (http://www.maizegdb.org/AllertonReport.doc), it has become evident that th...

  17. The MaizeGDB Genome Browser

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of a larger effort to develop MaizeGDB into a more sequence-centric resource, we recently implemented a genome browser. The GBrowse platform was chosen for this endeavor based on results of a survey...

  18. Genetically Modified Crops and Nuisance: Exploring the Role of Precaution in Private Law

    ERIC Educational Resources Information Center

    Craik, Neil; Culver, Keith; Siebrasse, Norman

    2007-01-01

    This article critically considers calls for the precautionary principle to inform judicial decision making in a private law context in light of the Hoffman litigation, where it is alleged that the potential for genetic contamination from genetically modified (GM) crops causes an unreasonable interference with the rights of organic farmers to use

  19. Genetically Modified Crops and Nuisance: Exploring the Role of Precaution in Private Law

    ERIC Educational Resources Information Center

    Craik, Neil; Culver, Keith; Siebrasse, Norman

    2007-01-01

    This article critically considers calls for the precautionary principle to inform judicial decision making in a private law context in light of the Hoffman litigation, where it is alleged that the potential for genetic contamination from genetically modified (GM) crops causes an unreasonable interference with the rights of organic farmers to use…

  20. Attitudes to genetically modified food over time: How trust in organizations and the media cycle predict support.

    PubMed

    Marques, Mathew D; Critchley, Christine R; Walshe, Jarrod

    2015-07-01

    This research examined public opinion toward genetically modified plants and animals for food, and how trust in organizations and media coverage explained attitudes toward these organisms. Nationally representative samples (N=8821) over 10 years showed Australians were less positive toward genetically modified animals compared to genetically modified plants for food, especially in years where media coverage was high. Structural equation modeling found that positive attitudes toward different genetically modified organisms for food were significantly associated with higher trust in scientists and regulators (e.g. governments), and with lower trust in watchdogs (e.g. environmental movement). Public trust in scientists and watchdogs was a stronger predictor of attitudes toward the use of genetically modified plants for food than animals, but only when media coverage was low. Results are discussed regarding the moral acceptability of genetically modified organisms for food, the media's role in shaping public opinion, and the role public trust in organizations has on attitudes toward genetically modified organisms. PMID:25063421

  1. Quantitative Genetic Dissection of Shoot Architecture Traits in Maize: Towards a Functional Genomics Approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative trait loci (QTL) affecting the total number of leaves (TNOL) made prior to flowering and the number of leaves below the ear (NLBE) were mapped and characterized in order to dissect the genetic regulatory components of these agronomically important traits of corn. The full set of interm...

  2. PREDICT CHROMOSOMAL LOCATIONS OF GENETICALLY MAPPED LOCI IN MAIZE USING THE MORGAN2MCCLINTOCK TRANSLATOR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Morgan2McClintock Translator is a web-based tool that enables researchers to automatically convert coordinates from genetic recombination-based linkage maps to predicted positions on meiotic pachytene chromosomes using previously determined recombination nodule frequency distributions. The outpu...

  3. Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of tra...

  4. Maize Leaf Epiphytic Bacteria Diversity Patterns Are Genetically Correlated with Resistance to Fungal Pathogen Infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant leaves host a specific set of microbial epiphytes. These phyllosphere organisms form a large community, with annual crops alone covering millions of hectares each year. Host plant genetic factors and abiotic stresses such as UV-B are key in shaping patterns of epiphyte diversity; we analyzed...

  5. Extensive genetic diversity and low linkage disequilibrium within the COMT locus in maize exotic populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Caffeic acid 3-O-methytransferase (COMT) gene is a prime candidate for cell wall digestibility improvement based on the characterization of brown midrib-3 mutants. We compared the genetic diversity and linkage disequilibrium at COMT locus between populations sampled within the Germplasm Enhance...

  6. On the Origin of Meiotic Reproduction: A Genetic Modifier Model

    PubMed Central

    Uyenoyama, M. K.; Bengtsson, B. O.

    1989-01-01

    We study the conditions under which a rare allele that modifies the relative rates of meiotic reproduction and apomixis increases in a population in which meiotic reproduction entails selfing as well as random outcrossing. A distinct locus, at which mutation maintains alleles that are lethal in homozygous form, determines viability. We find that low viability of carriers of the lethal alleles, high rates of selfing, dominance of the introduced modifier allele, and lower rates of recombination promote the evolution of meiosis. Meiotic reproduction can evolve even in the absence of linkage between the modifier and the viability locus. The adaptive value of meiotic reproduction depends on the relative viabilities of offspring derived by meiosis and by apomixis, and on associations between the modifier and the viability locus. Meiotic reproduction, particularly under selfing, generates more diverse offspring, including those with very high and very low viability. Elimination of offspring with low viability generates positive associations between enhancers of meiotic reproduction and high viability. In addition, partial selfing generates positive associations in heterozygosity (identity disequilibrium) between the modifier and the viability locus, even in the absence of linkage. The two kinds of associations together can compensate for initial reductions in mean offspring viability under meiotic reproduction. PMID:2612898

  7. A comparative analysis of media reporting of perceived risks and benefits of genetically modified crops and foods in Kenyan and international newspapers.

    PubMed

    DeRosier, Christopher; Sulemana, Iddisah; James, Harvey S; Valdivia, Corinne; Folk, William; Smith, Randall D

    2015-07-01

    We empirically examine the reporting on biotechnology in Kenyan and international newspapers between 2010 and early 2014. We identify news articles that reported on biotechnology and analyze their use of words to determine whether there is a balance in the reporting of perceived risks and benefits. We also consider how the sources used in news articles and how the publication of the Séralini study of rats fed genetically modified maize affect the balance of reporting of perceived risks and benefits. We find that in Kenyan news reporting, more articles mention perceived benefits than risks, but when risks are mentioned, new articles contain more references to risks than to benefits. We also find that sources affect the reporting of perceived risks and benefits and that the Séralini study increased the likelihood that perceived risks are reported in Kenyan news reporting, but not in international newspapers. PMID:25605748

  8. Genetically Modified T Cells for the Treatment of Malignant Disease

    PubMed Central

    Wieczorek, Agnieszka; Uharek, Lutz

    2013-01-01

    Summary The broaden application of adoptive T-cell transfer has been constrained by the technical abilities to isolate and expand antigen-specific T cells potent to selectively kill tumor cells. With the recent progress in the design and manufacturing of cellular products, T cells used in the treatment of malignant diseases may be regarded as anticancer biopharmaceuticals. Genetical manipulation of T cells has given T cells desired specificity but also enable to tailor their activation and proliferation potential. Here, we summarize the recent developments in genetic engineering of T-cell-based biopharmaceuticals, covering criteria for their clinical application in regard to safety and efficacy. PMID:24474888

  9. MaizeGDB's New Data Types, Resources, and Activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecul...

  10. MaizeGDB's new data types, resources, and activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecul...

  11. Functional Allelic Variation at Key Photoperiod Response QTL in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical maize represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. We tested ...

  12. Reasonable Foreseeability and Liability in Relation to Genetically Modified Organisms

    ERIC Educational Resources Information Center

    Khoury, Lara; Smyth, Stuart

    2007-01-01

    This article examines problems that may arise when addressing liability resulting from the genetic modification of microbes, animals, and plants. More specifically, it evaluates how uncertainties relating to the outcomes of these biotechnological innovations affect--or may affect--the courts' application of the reasonable foreseeability…

  13. Genetically Modified Food: Knowledge and Attitude of Teachers and Students

    ERIC Educational Resources Information Center

    Mohapatra, Animesh K.; Priyadarshini, Deepika; Biswas, Antara

    2010-01-01

    The concepts behind the technology of genetic modification of organisms and its applications are complex. A diverse range of opinions, public concern and considerable media interest accompanies the subject. This study explores the knowledge and attitudes of science teachers and senior secondary biology students about the application of a rapidly…

  14. Chemical and flavor profiles of genetically modified peanut varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut (Arachis hypogaea L.) is an economically important crop throughout the world. It is susceptible to many types of fungal pathogens. Genetic engineering offers great potential for developing peanut cultivars resistant to a broad spectrum of pathogens that pose a recurring threat to peanut hea...

  15. Genetically Modified Food: Knowledge and Attitude of Teachers and Students

    ERIC Educational Resources Information Center

    Mohapatra, Animesh K.; Priyadarshini, Deepika; Biswas, Antara

    2010-01-01

    The concepts behind the technology of genetic modification of organisms and its applications are complex. A diverse range of opinions, public concern and considerable media interest accompanies the subject. This study explores the knowledge and attitudes of science teachers and senior secondary biology students about the application of a rapidly

  16. Reasonable Foreseeability and Liability in Relation to Genetically Modified Organisms

    ERIC Educational Resources Information Center

    Khoury, Lara; Smyth, Stuart

    2007-01-01

    This article examines problems that may arise when addressing liability resulting from the genetic modification of microbes, animals, and plants. More specifically, it evaluates how uncertainties relating to the outcomes of these biotechnological innovations affect--or may affect--the courts' application of the reasonable foreseeability

  17. Improved bioavailability of calcium in genetically-modified carrots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osteoporosis is one of the world's most prevalent nutritional disorders, and inadequate absorbed calcium is a known contributor to the pathophysiology of this condition. In a cross-over study of 15 male and 15 female young adults, we used a dual stable isotope method with 42Ca-labeled genetically-mo...

  18. Genetic Dissection of Internode Length Above the Uppermost Ear in Four RIL Populations of Maize (Zea mays L.)

    PubMed Central

    Ku, Lixia; Cao, Liru; Wei, Xiaomin; Su, Huihui; Tian, Zhiqiang; Guo, Shulei; Zhang, Liangkun; Ren, Zhenzhen; Wang, Xiaobo; Zhu, Yuguang; Li, Guohui; Wang, Zhiyong; Chen, Yanhui

    2014-01-01

    The internode length above the uppermost ear (ILAU) is an important influencing factor for canopy architecture in maize. Analyzing the genetic characteristics of internode length is critical for improving plant population structure and increasing photosynthetic efficiency. However, the genetic control of ILAU has not been determined. In this study, quantitative trait loci (QTL) for internode length at five positions above the uppermost ear were identified using four sets of recombinant inbred line (RIL) populations in three environments. Genetic maps and initial QTL were integrated using meta-analyses across the four populations. Seventy QTL were identified: 16 in population 1; 14 in population 2; 25 in population 3; and 15 in population 4. Individual effects ranged from 5.36% to 26.85% of phenotypic variation, with 27 QTL >10%. In addition, the following common QTL were identified across two populations: one common QTL for the internode length of all five positions; one common QTL for the internode length of three positions; and one common QTL for the internode length of one position. In addition, four common QTL for the internode length of four positions were identified in one population. The results indicated that the ILAU at different positions above the uppermost ear could be affected by one or several of the same QTL. The traits may also be regulated by many different QTL. Of the 70 initial QTL, 46 were integrated in 14 meta-QTL (mQTLs) by meta-analysis, and 17 of the 27 initial QTL with R2 >10% were integrated in 7 mQTLs. Four of the key mQTLs (mQTL2-2, mQTL3-2, mQTL5-1, mQTL5-2, and mQTL9) in which the initial QTL displayed R2 >10% included four to 11 initial QTL for an internode length of four to five positions from one or two populations. These results may provide useful information for marker-assisted selection to improve canopy architecture. PMID:25538101

  19. Do Environmental Factors Modify the Genetic Risk of Prostate Cancer?

    PubMed Central

    Loeb, Stacy; Peskoe, Sarah B.; Joshu, Corinne E.; Huang, Wen-Yi; Hayes, Richard B.; Carter, H. Ballentine; Isaacs, William B.; Platz, Elizabeth A.

    2015-01-01

    Background Many SNPs influence prostate cancer risk. To what extent genetic risk can be reduced by environmental factors is unknown. Methods We evaluated effect modification by environmental factors of the association between susceptibility SNPs and prostate cancer in 1,230 incident prostate cancer cases and 1,361 controls, all white and similar ages, nested in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Trial. Genetic risk scores were calculated as number of risk alleles for 20 validated SNPs. We estimated the association between higher genetic risk (≥ 12 SNPs) and prostate cancer within environmental factor strata and tested for interaction. Results Men with ≥12 risk alleles had 1.98, 2.04, and 1.91 times the odds of total, advanced, and nonadvanced prostate cancer, respectively. These associations were attenuated with the use of selenium supplements, aspirin, ibuprofen, and higher vegetable intake. For selenium, the attenuation was most striking for advanced prostate cancer: compared with <12 alleles and no selenium, the OR for ≥12 alleles was 2.06 [95% confidence interval (CI), 1.67–2.55] in nonusers and 0.99 (0.38–2.58) in users (Pinteraction = 0.031). Aspirin had the most marked attenuation for nonadvanced prostate cancer: compared with <12 alleles and nonusers, the OR for ≥12 alleles was 2.25 (1.69–3.00) in nonusers and 1.70 (1.25–2.32) in users (Pinteraction = 0.009). This pattern was similar for ibuprofen (Pinteraction = 0.023) and vegetables (Pinteraction = 0.010). Conclusions This study suggests that selenium supplements may reduce genetic risk of advanced prostate cancer, whereas aspirin, ibuprofen, and vegetables may reduce genetic risk of nonadvanced prostate cancer. PMID:25342390

  20. Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed

    Hawes, C; Haughton, A J; Osborne, J L; Roy, D B; Clark, S J; Perry, J N; Rothery, P; Bohan, D A; Brooks, D R; Champion, G T; Dewar, A M; Heard, M S; Woiwod, I P; Daniels, R E; Young, M W; Parish, A M; Scott, R J; Firbank, L G; Squire, G R

    2003-11-29

    Effects of genetically modified herbicide-tolerant (GMHT) and conventional crop management on invertebrate trophic groups (herbivores, detritivores, pollinators, predators and parasitoids) were compared in beet, maize and spring oilseed rape sites throughout the UK. These trophic groups were influenced by season, crop species and GMHT management. Many groups increased twofold to fivefold in abundance between early and late summer, and differed up to 10-fold between crop species. GMHT management superimposed relatively small (less than twofold), but consistent, shifts in plant and insect abundance, the extent and direction of these effects being dependent on the relative efficacies of comparable conventional herbicide regimes. In general, the biomass of weeds was reduced under GMHT management in beet and spring oilseed rape and increased in maize compared with conventional treatments. This change in resource availability had knock-on effects on higher trophic levels except in spring oilseed rape where herbivore resource was greatest. Herbivores, pollinators and natural enemies changed in abundance in the same directions as their resources, and detritivores increased in abundance under GMHT management across all crops. The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web. The Farm Scale Evaluations have demonstrated over 3 years and throughout the UK that herbivores, detritivores and many of their predators and parasitoids in arable systems are sensitive to the changes in weed communities that result from the introduction of new herbicide regimes. PMID:14561321

  1. Invertebrates and vegetation of field margins adjacent to crops subject to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed

    Roy, D B; Bohan, D A; Haughton, A J; Hill, M O; Osborne, J L; Clark, S J; Perry, J N; Rothery, P; Scott, R J; Brooks, D R; Champion, G T; Hawes, C; Heard, M S; Firbank, L G

    2003-11-29

    The effects of management of genetically modified herbicide-tolerant (GMHT) crops on adjacent field margins were assessed for 59 maize, 66 beet and 67 spring oilseed rape sites. Fields were split into halves, one being sown with a GMHT crop and the other with the equivalent conventional non-GMHT crop. Margin vegetation was recorded in three components of the field margins. Most differences were in the tilled area, with fewer smaller effects mirroring them in the verge and boundary. In spring oilseed rape fields, the cover, flowering and seeding of plants were 25%, 44% and 39% lower, respectively, in the GMHT uncropped tilled margins. Similarly, for beet, flowering and seeding were 34% and 39% lower, respectively, in the GMHT margins. For maize, the effect was reversed, with plant cover and flowering 28% and 67% greater, respectively, in the GMHT half. Effects on butterflies mirrored these vegetation effects, with 24% fewer butterflies in margins of GMHT spring oilseed rape. The likely cause is the lower nectar supply in GMHT tilled margins and crop edges. Few large treatment differences were found for bees, gastropods or other invertebrates. Scorching of vegetation by herbicide-spray drift was on average 1.6% on verges beside conventional crops and 3.7% beside GMHT crops, the difference being significant for all three crops. PMID:14561320

  2. ASSESSING POSSIBLE ECOLOGICAL RISKS OF GENETICALLY MODIFIED CROPS: GENE EXPRESSION ASSAYS AND GENETIC MONITORING OF NON-TARGET ORGANISMS

    EPA Science Inventory

    Widespread planting of genetically modified crops with the Bt transgene pesticide has led to concern over non-target effects of Bt compounds in agroecosystems. While some research suggests that non-target organisms exposed to Bt toxin exhibit reduced fecundity and increased morta...

  3. Systemic delivery of recombinant proteins by genetically modified myoblasts

    SciTech Connect

    Barr, E.; Leiden, J.M. )

    1991-12-06

    The ability to stably deliver recombinant proteins to the systemic circulation would facilitate the treatment of a variety of acquired and inherited diseases. To explore the feasibility of the use of genetically engineered myoblasts as a recombinant protein delivery system, stable transfectants of the murine C2C12 myoblast cell line were produced that synthesize and secrete high levels of human growth hormone (hGH) in vitro. Mice injected with hGH-transfected myoblasts had significant levels of hGH in both muscle and serum that were stable for at least 3 weeks after injection. Histological examination of muscles injected with {beta}-galactosidase-expressing C2C12 myoblasts demonstrated that many of the injected cells had fused to form multinucleated myotubes. Thus, genetically engineered myoblasts can be used for the stable delivery of recombinant proteins into the circulation.

  4. Data in support of the detection of genetically modified organisms (GMOs) in food and feed samples.

    PubMed

    Alasaad, Noor; Alzubi, Hussein; Kader, Ahmad Abdul

    2016-06-01

    Food and feed samples were randomly collected from different sources, including local and imported materials from the Syrian local market. These included maize, barley, soybean, fresh food samples and raw material. GMO detection was conducted by PCR and nested PCR-based techniques using specific primers for the most used foreign DNA commonly used in genetic transformation procedures, i.e., 35S promoter, T-nos, epsps, cryIA(b) gene and nptII gene. The results revealed for the first time in Syria the presence of GM foods and feeds with glyphosate-resistant trait of P35S promoter and NOS terminator in the imported soybean samples with high frequency (5 out of the 6 imported soybean samples). While, tests showed negative results for the local samples. Also, tests revealed existence of GMOs in two imported maize samples detecting the presence of 35S promoter and nos terminator. Nested PCR results using two sets of primers confirmed our data. The methods applied in the brief data are based on DNA analysis by Polymerase Chain Reaction (PCR). This technique is specific, practical, reproducible and sensitive enough to detect up to 0.1% GMO in food and/or feedstuffs. Furthermore, all of the techniques mentioned are economic and can be applied in Syria and other developing countries. For all these reasons, the DNA-based analysis methods were chosen and preferred over protein-based analysis. PMID:26958644

  5. Identity preservation of genetically modified organisms in the food chain: requirements, methods, and costs.

    PubMed

    Brookes, Graham

    2002-01-01

    The use of the technology of genetic modification (GM) in European agriculture and the food supply chain is currently controversial. Because of strong anti-GM technology sentiments, the use of ingredients derived from plants containing GM have largely been eliminated from foods manufactured for direct human consumption by the food supply chain in much of the European Union (EU). During the past year, the attention of those opposed to the technology has turned to the use of GM ingredients in livestock production systems by incorporation of GM soy and maize in animal feed. A discussion is presented of the key issues relating to this subject, focusing on how supplies of GM or non-GM products are segregated or how their identities are preserved. The discussion is centered on GM maize and soybeans into which agronomic traits, such as herbicide tolerance and/or insect resistance, have been incorporated. These are currently the only crops into which some varieties containing GM have been approved for use in the EU. PMID:12083272

  6. Data in support of the detection of genetically modified organisms (GMOs) in food and feed samples

    PubMed Central

    Alasaad, Noor; Alzubi, Hussein; Kader, Ahmad Abdul

    2016-01-01

    Food and feed samples were randomly collected from different sources, including local and imported materials from the Syrian local market. These included maize, barley, soybean, fresh food samples and raw material. GMO detection was conducted by PCR and nested PCR-based techniques using specific primers for the most used foreign DNA commonly used in genetic transformation procedures, i.e., 35S promoter, T-nos, epsps, cryIA(b) gene and nptII gene. The results revealed for the first time in Syria the presence of GM foods and feeds with glyphosate-resistant trait of P35S promoter and NOS terminator in the imported soybean samples with high frequency (5 out of the 6 imported soybean samples). While, tests showed negative results for the local samples. Also, tests revealed existence of GMOs in two imported maize samples detecting the presence of 35S promoter and nos terminator. Nested PCR results using two sets of primers confirmed our data. The methods applied in the brief data are based on DNA analysis by Polymerase Chain Reaction (PCR). This technique is specific, practical, reproducible and sensitive enough to detect up to 0.1% GMO in food and/or feedstuffs. Furthermore, all of the techniques mentioned are economic and can be applied in Syria and other developing countries. For all these reasons, the DNA-based analysis methods were chosen and preferred over protein-based analysis. PMID:26958644

  7. Genetic dissection of maize seedling root system architecture traits using an ultra-high density bin-map and a recombinant inbred line population.

    PubMed

    Song, Weibin; Wang, Baobao; Hauck, Andrew L; Dong, Xiaomei; Li, Jieping; Lai, Jinsheng

    2016-03-01

    Maize (Zea mays) root system architecture (RSA) mediates the key functions of plant anchorage and acquisition of nutrients and water. In this study, a set of 204 recombinant inbred lines (RILs) was derived from the widely adapted Chinese hybrid ZD958(Zheng58 × Chang7-2), genotyped by sequencing (GBS) and evaluated as seedlings for 24 RSA related traits divided into primary, seminal and total root classes. Significant differences between the means of the parental phenotypes were detected for 18 traits, and extensive transgressive segregation in the RIL population was observed for all traits. Moderate to strong relationships among the traits were discovered. A total of 62 quantitative trait loci (QTL) were identified that individually explained from 1.6% to 11.6% (total root dry weight/total seedling shoot dry weight) of the phenotypic variation. Eighteen, 24 and 20 QTL were identified for primary, seminal and total root classes of traits, respectively. We found hotspots of 5, 3, 4 and 12 QTL in maize chromosome bins 2.06, 3.02-03, 9.02-04, and 9.05-06, respectively, implicating the presence of root gene clusters or pleiotropic effects. These results characterized the phenotypic variation and genetic architecture of seedling RSA in a population derived from a successful maize hybrid. PMID:26593310

  8. Silicon alleviates cadmium toxicity by enhanced photosynthetic rate and modified bundle sheath's cell chloroplasts ultrastructure in maize.

    PubMed

    Vaculík, Marek; Pavlovič, Andrej; Lux, Alexander

    2015-10-01

    Silicon was shown to alleviate the negative effects of various biotic and abiotic stresses on plant growth. Although the positive role of Si on toxic and heavy metal Cd has been already described, the mechanisms have been explained only partially and still remain unclear. In the present study we investigated the effect of Si on photosynthetic-related processes in maize exposed to two different levels of Cd via measurements of net photosynthetic rate (AN), chlorophyll a fluorescence and pigment analysis, as well as studies of leaf tissue anatomy and cell ultrastructure using bright-field and transmission electron microscopy. We found that Si actively alleviated the toxic syndromes of Cd by increasing AN, effective photochemical quantum yield of photosystem II (ϕPSII) and content of assimilation pigments, although did not decrease the concentration of Cd in leaf tissues. Cadmium did not affect the leaf anatomy and ultrastructure of leaf mesophyll's cell chloroplasts; however, Cd negatively affected thylakoid formation in chloroplasts of bundle sheath cells, and this was alleviated by Si. Improved thylakoid formation in bundle sheath's cell chloroplasts may contribute to Si-induced enhancement of photosynthesis and related increase in biomass production in C4 plant maize. PMID:26036417

  9. Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape

    PubMed Central

    Tank, Jennifer L.; Rosi-Marshall, Emma J.; Royer, Todd V.; Whiles, Matt R.; Griffiths, Natalie A.; Frauendorf, Therese C.; Treering, David J.

    2010-01-01

    Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% of the 2009 US maize crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis. Six months after harvest, we conducted a synoptic survey of 217 stream sites in Indiana to determine the extent of maize detritus and presence of Cry1Ab protein in the stream network. We found that 86% of stream sites contained maize leaves, cobs, husks, and/or stalks in the active stream channel. We also detected Cry1Ab protein in stream-channel maize at 13% of sites and in the water column at 23% of sites. We found that 82% of stream sites were adjacent to maize fields, and Geographical Information Systems analyses indicated that 100% of sites containing Cry1Ab-positive detritus in the active stream channel had maize planted within 500 m during the previous crop year. Maize detritus likely enters streams throughout the Corn Belt; using US Department of Agriculture land cover data, we estimate that 91% of the 256,446 km of streams/rivers in Iowa, Illinois, and Indiana are located within 500 m of a maize field. Maize detritus is common in low-gradient stream channels in northwestern Indiana, and Cry1Ab proteins persist in maize leaves and can be measured in the water column even 6 mo after harvest. Hence, maize detritus, and associated Cry1Ab proteins, are widely distributed and persistent in the headwater streams of a Corn Belt landscape. PMID:20876106

  10. MaizeGDB update: new tools, data and interface for the maize model organism database

    PubMed Central

    Andorf, Carson M.; Cannon, Ethalinda K.; Portwood, John L.; Gardiner, Jack M.; Harper, Lisa C.; Schaeffer, Mary L.; Braun, Bremen L.; Campbell, Darwin A.; Vinnakota, Abhinav G.; Sribalusu, Venktanaga V.; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D.; Mauch, Emily D.; Rao, Bhavani S.; Birkett, Scott M.; Sen, Taner Z.; Lawrence-Dill, Carolyn J.

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  11. MaizeGDB update: new tools, data and interface for the maize model organism database.

    PubMed

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  12. The genetic structure of Asian corn borer, Ostrinia furnacalis, populations in China: haplotype variance in northern populations and potential impact on management of resistance to transgenic maize.

    PubMed

    Li, Jing; Coates, Brad S; Kim, Kyung Seok; Bourguet, Denis; Ponsard, Sergine; He, Kanglai; Wang, Zhenying

    2014-01-01

    Asian corn borer, Ostrinia furnacalis (Guenée), is a severe pest that infests cultivated maize in the major production regions of China. Populations show genotype-by-environment variation in voltinism, such that populations with a single generation (univoltine) are fixed in Northern China where growing seasons are short. Low genetic differentiation was found among samples from 33 collection sites across China and one site from North Korea (n=1673) using variation at 6 nuclear microsatellite loci (ENA corrected global FST=0.020; P value<0.05). Analysis of molecular variance indicated that geographic region, number of generations or voltinism accounted for <0.38% of the total genetic variation at nuclear loci and was corroborated by clustering of co-ancestries among genotypes using the program STRUCTURE. In contrast, a mitochondrial haplotype network identified 4 distinct clusters, where 70.5% of samples from univoltine populations were within a single group. Univoltine populations were also placed into a unique cluster using Population Graph and Principal component analyses, which showed significant differentiation with multivoltine populations (φST=0.400; P value<0.01). This study suggests that gene flow among O. furnacalis in China may be high among regions, with the exception of northeastern localities. Haplotype variation may be due to random genetic drift resulting from partial reproductive isolation between univoltine and multivoltine O. furnacalis populations. Such reproductive isolation might impact the potential spread of alleles that confer resistance to transgenic maize in China. PMID:25024271

  13. Association Between the Body Mass Index and Prostate Cancer at Biopsy is Modified by Genetic Risk

    PubMed Central

    Zhang, Gui-Ming; Zhu, Yao; Chen, Hai-Tao; Han, Cheng-Tao; Liu, Fang; Xu, Jian-Feng; Ye, Ding-Wei

    2015-01-01

    Abstract Herein, we aimed to examine whether the association of body mass index (BMI) with prostate cancer (PCa) at biopsy differs according to genetic susceptibility. In a multicenter prospective cohort including 1120 men undergoing diagnostic prostate biopsy in China, we evaluated the interaction between BMI and genetic risk score (GRS) comprising 24 PCa-associated single nucleotide polymorphisms (SNPs), as well as a GRS consisting of 7 SNPs derived from an East-Asian population. The genetic risk was defined as low, intermediate, or high when GRS fell in the first, second, and third tertiles, respectively. We observed a significant interaction between BMI and PCa GRS (Pinteraction = 0.047), suggesting that the predictive value of BMI on PCa was strongly modified by genetic susceptibility. In men with high genetic risk, BMI was an independent predictor of PCa (odds ratio [OR] = 1.167, P = 0.008) after adjusting for conventional risk factors. The relationship between BMI and PCa risk diminished (P = 0.990) in men with low genetic risk. The interaction was more pronounced with the East-Asian GRS (Pinteraction = 0.032), suggesting that the overall GRS interaction most likely occurs through genetic susceptibility in the East-Asian population. Our results suggest that the predictive effect of BMI on the PCa risk is strongly modified by individual genetic susceptibility. The association is more positive among men with high genetic risk for PCa. PMID:26496266

  14. Creating genetically modified pigs by using nuclear transfer

    PubMed Central

    Lai, Liangxue; Prather, Randall S

    2003-01-01

    Nuclear transfer (NT) is a procedure by which genetically identical individuals can be created. The technology of pig somatic NT, including in vitro maturation of oocytes, isolation and treatment of donor cells, artificial activation of reconstructed oocytes, embryo culture and embryo transfer, has been intensively studied in recent years, resulting in birth of cloned pigs in many labs. While it provides an efficient method for producing transgenic pigs, more importantly, it is the only way to produce gene-targeted pigs. So far pig cloning has been successfully used to produce transgenic pigs expressing the green fluorescence protein, expand transgenic pig groups and create gene targeted pigs which are deficient of alpha-1,3-galactosyltransferase. The production of pigs with genetic modification by NT is now in the transition from investigation to practical use. Although the efficiency of somatic cell NT in pig, when measured as development to term as a proportion of oocytes used, is not high, it is anticipated that the ability of making specific modifications to the swine genome will result in this technology having a large impact not only on medicine but also on agriculture. PMID:14613542

  15. Reducing photoperiod response of tropical maize germplasm for use in Midwestern maize introgression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize Project (GEM) is a cooperative effort of USDA-ARS, public and private sector scientists to broaden the genetic diversity of maize germplasm. Tropical maize germplasm is an important source of alleles for biotic and abiotic stress resistance and numerous value-adde...

  16. MaizeGDB: Global support for maize research through open access information [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the open-access global repository for maize genetic and genomic information – from single genes that determine nutritional quality to whole genome-scale data for complex traits including yield and drought tolerance. The data and tools at MaizeGDB enable researchers from Ethiopia to Ghan...

  17. Cytokine Secretion by Genetically Modified Nonimmunogenic Murine Fibrosarcoma

    PubMed Central

    Karp, Stephen E.; Farber, Alik; Salo, Jonathan C.; Hwu, Patrick; Jaffe, Gitie; Asher, Anthony L.; Shiloni, Eitan; Restifo, Nicholas P.; Mulé, James J.; Rosenberg, Steven A.

    2007-01-01

    Recent investigations have demonstrated that the in vivo growth of weakly immunogenic murine tumors can be inhibited by genetic manipulations that enable them to secrete a variety of cytokines. Inasmuch as most human tumors fail to elicit a detectable host immune response we questioned whether the growth of a nonimmunogenic murine tumor could be inhibited by the secretion of cytokines. We have thus inserted the cDNA encoding for human IL-2 or TNF into the nonimmunogenic murine fibrosarcoma MCA 102. Tumor cells secreting IL-2 failed to grow in vivo despite normal in vitro growth. This growth inhibition required an intact immune system as tumors grew progressively in mice sublethally irradiated before tumor injection. Tumor inhibition was abrogated by the in vivo depletion, by specific mAb before tumor injection, of either CD8+ T cells or NK cells, but not CD4+ T cells. IL-2 secretion by tumor afforded a significant survival benefit to the animal, and IL-2-secreting tumor limited the growth of admixed nonsecreting parental tumor. Histologic evidence and FACS analyses revealed a dense lymphocytic infiltration of IL-2-secreting tumors composed of both CD4+ and CD8+ T cells. In contrast, secretion of TNF failed to inhibit the growth of MCA 102, and similar lymphocyte subset depletions, or administration of specific anti-TNF mAb had no effect on the growth of TNF secreting MCA 102. In summary, these investigations demonstrated that the host response to this nonimmunogenic tumor can be markedly enhanced by the genetic manipulation of the tumor cells to secrete IL-2, but not TNF. This strategy has potential application for the development of immunotherapies for nonimmunogenic tumors. PMID:8423345

  18. The Locus Lookup Tool at MaizeGDB: Identification of Genomic Regions in Maize by Integrating Sequence Information with Physical and Genetic Maps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods to automatically integrate sequence information with physical and genetic maps are scarce. The Locus Lookup Tool enables researchers to define windows of genomic sequence likely to contain loci of interest where only genetic or physical mapping associations are reported. Using the Locus Look...

  19. Different Effects of Transgenic Maize and Nontransgenic Maize on Nitrogen-Transforming Archaea and Bacteria in Tropical Soils

    PubMed Central

    Cotta, Simone Raposo; Dias, Armando Cavalcante Franco; Marriel, Ivanildo Evódio; Andreote, Fernando Dini; van Elsas, Jan Dirk

    2014-01-01

    The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCR-denaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants. PMID:25107970

  20. Genetic Relationships, Carbendazim Sensitivity and Mycotoxin Production of the Fusarium Graminearum Populations from Maize, Wheat and Rice in Eastern China

    PubMed Central

    Qiu, Jianbo; Shi, Jianrong

    2014-01-01

    Members of the Fusarium graminearum species complex (FGSC) are important pathogens on wheat, maize, barley, and rice in China. Harvested grains are often contaminated by mycotoxins, such as the trichothecene nivalenol (NIV) and deoxynivalenol (DON) and the estrogenic mycotoxin zearalenone (ZEN), which is a big threat to humans and animals. In this study, 97 isolates were collected from maize, wheat, and rice in Jiangsu and Anhui provinces in 2013 and characterized by species- and chemotype-specific PCR. F. graminearum sensu stricto (s. str.) was predominant on maize, while most of the isolates collected from rice and wheat were identified as F. asiaticum. Fusarium isolates from three hosts varied in trichothecene chemotypes. The 3-acetyldeoxynivalenol (3ADON) chemotype predominated on wheat and rice population, while 15ADON was prevailing in the remaining isolates. Sequence analysis of the translation elongation factor 1α and trichodiene synthase indicated the accuracy of the above conclusion. Additionally, phylogenetic analysis suggested four groups with strong correlation with species, chemotype, and host. These isolates were also evaluated for their sensitivity to carbendazim and mycotoxins production. The maize population was less sensitive than the other two. The DON levels were similar in three populations, while those isolates on maize produced more ZEN. More DON was produced in carbendazim resistant strains than sensitive ones, but it seemed that carbendazim resistance had no effect on ZEN production in wheat culture. PMID:25093387