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Pre-clinical evaluation and improvement of attenuated malaria sporozoite vaccine candidatesKreutzfeld, Oriana 16 January 2020 (has links)
Malaria Impfstoffkandidaten, welche Sicherheit und Wirksamkeit gegen prä-erythrozytische Stadien bieten, sind nach wie vor in der Entwicklung. Experimentelle Immunisierungsstudien mit genetisch attenuierten Parasiten (GAP), welche die Entwicklung über das klinisch asymptomatische Leberstadium hinaus verhindern, erwiesen sich als sicher und effizient. ΔSLARP GAP-Sporozoiten arretieren vollständig in der Leber, bieten jedoch keinen langanhaltenden Schutz. Hingegen zeigen Immunisierungen mit ΔP36p/P36 Sporozoiten einen langanhaltenden Schutz, führen jedoch während der Immunisierung gelegentlich zu Blutstadieninfektionen. Diese Studie liefert eine systematische vorklinische Bewertung eines dreifachen KO GAP-Parasiten, durch die Kombination von ΔSLARP und ΔP36p/P36. KO Parasiten arretierten vollständig in vitro und in vivo, aber der zeitnahe Blutinfektionsbeginn nach einer Sporozoiteninfektion in Mäusen zeigte eine verminderte Wirksamkeit des Impfstoffs. Während ein besserer Schutz durch einen späten Leberstadien Entwicklungsstillstand erreicht werden kann, bleiben die zugrundeliegenden molekularen Mechanismen unklar. Eine Vorrausetzung für die Leberzellen Antigenpräsentation ist die Präsenz von parasitären Antigenen im hepatozyten Zytoplasma. Der Proteinexportkomplex PTEX ist in Leberstadien nicht vollständig funktionstüchtig, da das essentielle Hitzeschockprotein 101 (HSP101) nicht exprimiert wird. Um die Rolle von HSP101 für den Leberproteinexport zu klären, wurden transgene HSP101 exprimierende Parasiten erzeugt. Transgene Parasiten weisen in vitro und in vivo schwere Wachstumsstörungen im Leberstadium auf und bieten keinen Impfschutz. Die Ergebnisse legen nahe, dass die Expression von HSP101 streng kontrolliert wird und der Export im frühen Leberstadien nicht wiederhergestellt werden kann. Insgesamt können prä-klinische Studien und die Weiterentwicklung von GAP-basierten Impfstoffkandidaten die laufenden humanen Impfstoffstudien beeinflussen und vorantreiben. / Malaria vaccine candidates providing both safety and efficacy against pre-erythrocytic stages remain largely elusive. Experimental immunizations with live genetically attenuated parasites (GAPs) preventing the development beyond the clinically silent liver stage have proven safe and efficacious. GAP vaccine candidate ΔSLARP, provides the most robust life cycle arrest, however, immunizations do not elicit long-lasting immunity. In contrast, ΔP36p/P36 sporozoites elicit long-lasting immunity, but lead to breakthrough infections during immunizations. This study gives a systematic pre-clinical evaluation of a triple knockout (tKO) GAP by combining ΔSLARP and ΔP36p/P36. Complete arrest of tKO parasites in cultured hepatoma cells and sporozoite-infected mice was confirmed, but time to blood infection after a sporozoite challenge revealed reduced efficacy of the tKO vaccine. While superior immunity can be achieved by a late developmental arrest at liver-to-blood stage conversion, the underlying molecular mechanisms remain elusive. An important question is whether parasite antigens are exposed to the hepatocyte cytoplasm. Protein translocation into the host cell cytoplasm mediated by PTEX, a protein translocon, is absent during liver stage maturation as a core component of PTEX, Heat-shock-protein 101 (HSP101), is not expressed. To clarify the role of HSP101 in liver stage protein export transgenic HSP101 expressing Plasmodium berghei parasites were generated. Parasites expressing elevated levels of HSP101 show severe liver stage growth defects in vitro and in vivo, lack early liver stage export and inferior protection in immunized animals. Our results suggest that HSP101 expression is tightly controlled and PTEX dependent early liver stage export cannot be restored solely by HSP101 overexpression. Overall, pre-clinical analysis and improvement of GAP-based vaccine candidates can inform on-going human vaccine trials and boost malaria vaccine development.
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Implications of environmental educators' perceptions regarding the use of genetically modified crops towards sustainable developmentLe Roux, Stephanus Jacobus 30 November 2004 (has links)
Genetically modified (GM) crops gained attention in southern Africa as countries are struggling with food insecurity and poverty to achieve sustainable development. The controversy around GM crops have provoked heated debates. GM crops are often perceived as a global risk to human health and the environment. The research question is what are the perceptions of environmental educators regarding the use of GM crops toward sustainable development. In the Decade of Education for Sustainable Development environmental educators will need to be key role players in addressing crucial issues such as GM crops. Their perceptions hold many implications for educational programmes. Environmental educators interviewed perceive GM crops as a serious issue. As mediators in a multidisciplinary setting between science and society, environmental educators can play a functional role. Open processes that require greater participation, criticality and reflexivity need to be facilitated in a complex biophysical and social context in southern Africa. / Educational Studies / M. Ed.(Environmental Education)
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Evaluación de los efectos no intencionados de los transgenes en plantas modificadas genéticamente (MG) resistentes a plagas y diseñadas como biofactorías de péptidos antimicrobianosMontero Mirabet, Maria 22 June 2012 (has links)
Genetically modified crops are submitted to strict regulation to ensure the safety of consumers and the environment. To complement the comparison between GM plants and their counterparts, in the present Thesis, we evaluated the possible unexpected effects of the transgene on the host plant, by means of transcriptomic technologies. More exactly, we studied three pathogen-resistant GM rice lines: S-afp, expressing constitutively the antifungal protein AFP; and S-bp217 and S-bp213, expressing undecapeptide BP100 derivatives, which were developed in the UdG in the context of this Thesis. Although the high phytotoxicity of the BP100 derivatives on the host plant the transcriptional changes observed in S-afp, S-bp217 and S-bp213 compared to the conventional line Senia were similar that those observed in other GM crops, of other species and with different transgenes, and only the half of them was attributed to the insertion and/or expression of the transgene. / Les plantes modificades genèticament (MG) destinades a comercialització estan sotmeses a estricta legislació per garantir la seguretat del consumidor i del medi ambient. Per complementar la comparativa entre plantes MG i convencionals, en aquesta tesi s’ha abordat l’avaluació dels possibles efectes no esperats del transgèn sobre la planta hoste, mitjançant tècniques de transcriptòmica. Concretament s’han estudiat línies d'arròs MG que presenten fenotips de resistència a patògens: S-afp, que expressa constitutivament la proteïna antifúngica AFP, i S-bp213 i S-bp217, que expressen derivats de l’undecapèptid BP100, desenvolupat a la UdG, que s’han obtingut també en el marc d’aquesta tesi. Malgrat l’elevada fitotoxicitat dels derivats de BP100 enfront la planta hoste, els canvis transcripcionals de S-afp, S-bp213 i S-bp217 respecte la línia convencional Senia són similars als observats en altres events MG, de diferents espècies i amb diferents transgens; i només la meitat d’ells s’ha atribuit a la presència o expressió del transgèn.
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Implications of environmental educators' perceptions regarding the use of genetically modified crops towards sustainable developmentLe Roux, Stephanus Jacobus 30 November 2004 (has links)
Genetically modified (GM) crops gained attention in southern Africa as countries are struggling with food insecurity and poverty to achieve sustainable development. The controversy around GM crops have provoked heated debates. GM crops are often perceived as a global risk to human health and the environment. The research question is what are the perceptions of environmental educators regarding the use of GM crops toward sustainable development. In the Decade of Education for Sustainable Development environmental educators will need to be key role players in addressing crucial issues such as GM crops. Their perceptions hold many implications for educational programmes. Environmental educators interviewed perceive GM crops as a serious issue. As mediators in a multidisciplinary setting between science and society, environmental educators can play a functional role. Open processes that require greater participation, criticality and reflexivity need to be facilitated in a complex biophysical and social context in southern Africa. / Educational Studies / M. Ed.(Environmental Education)
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Microbial community structure and nematode diversity in soybean-based cropping systems / Chantelle JansenJansen, Chantelle January 2014 (has links)
Soil is an important ecosystem that supports a wide variety of organisms such as bacteria,
fungi, arthropods and nematodes. This sensitive ecosystem may be influenced by various
factors, including agricultural management practices. With the introduction of genetically
modified (GM) glyphosate-tolerant (RoundUp ® Ready: RR) crops, herbicides such as
glyphosate have been increasingly used. However, little is known about the effect of
glyphosate on the biological communities in these herbicide-sprayed soils. With the intimate
proximity that microorganisms and nematodes have with the roots of plants, these
organisms can be used to assess changes that may occur in the soil surrounding roots of
RR crops. The aim of this study was to determine microbial community structure and
nematode diversity, with emphasis on that of non-parasitic nematodes, in soil samples from
conventional soybean (CS) - and RR- soybean fields compared to that in adjacent natural
veld (NV) areas.
Samples were collected from twenty three sites at six localities that are situated within the
soybean-production areas of South Africa. These sites represented fields where RR and CS
soybean grew, as well as surrounding NV. All RR fields have been treated with glyphosate
for no less than five years. Microbial community structures of the twenty three sites in the
RR, CS and NV ecosystems were determined by phospholipid fatty acid (PLFA) analyses.
Nematode diversity was determined by extracting the nematodes from soil samples and
conducting a faunal analysis. Soil physical and chemical properties were determined by an
independent laboratory, Eco-Analytica (North West University, Potchefstroom) according to
standard procedures.
Results from this study indicated differences in microbial community structure between the
various localities. However, there were no significant (p ≤ 0.05) differences in microbial
community structures between RR- and CS ecosystems. Soils of both RR- and CS crops
were primarily dominated by bacteria. Nematode identification and faunal analysis also
indicated no significant (p ≤ 0.05) differences between the different non-parasitic/beneficial
nematodes that were present in soils of these two ecosystems during the time of sampling.
Non-parasitic nematode communities were primarily dominated by bacterivores. A faunal
analysis indicated that most of the sites contained enriched, but unstructured soil food-webs.
However, four of the sites showed enriched and structured food webs due to the presence of
non-parasitic nematodes with high coloniser-persister (cp) values. Relationships between non-parasitic nematode – and microbial communities showed that there was a positive
relationship between nematode functional groups and their corresponding microbial prey.
From the results obtained in this study, it can be concluded that the community structures of
both non-parasitic nematodes and microorganisms shared similarities. These community
structures showed no long-term detrimental effects of glyphosate application in the soils
surrounding roots of RR soybean crops. Relationships existed between non-parasitic
nematode and microbial communities in the rhizosphere of soybean crops and natural veld.
For example, bacterivore nematodes had a strong positive relationship with gram-negative
bacteria. Similar but weaker relationships also existed between carnivores, omnivores, plantparasitic
nematodes and gram-negative bacteria. A positive relationship also existed
between fungivores and fungal fatty acids. This emphasises the value of these organisms as
indicators of soil health and also the impact that agricultural practices can have on soils. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
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Microbial community structure and nematode diversity in soybean-based cropping systems / Chantelle JansenJansen, Chantelle January 2014 (has links)
Soil is an important ecosystem that supports a wide variety of organisms such as bacteria,
fungi, arthropods and nematodes. This sensitive ecosystem may be influenced by various
factors, including agricultural management practices. With the introduction of genetically
modified (GM) glyphosate-tolerant (RoundUp ® Ready: RR) crops, herbicides such as
glyphosate have been increasingly used. However, little is known about the effect of
glyphosate on the biological communities in these herbicide-sprayed soils. With the intimate
proximity that microorganisms and nematodes have with the roots of plants, these
organisms can be used to assess changes that may occur in the soil surrounding roots of
RR crops. The aim of this study was to determine microbial community structure and
nematode diversity, with emphasis on that of non-parasitic nematodes, in soil samples from
conventional soybean (CS) - and RR- soybean fields compared to that in adjacent natural
veld (NV) areas.
Samples were collected from twenty three sites at six localities that are situated within the
soybean-production areas of South Africa. These sites represented fields where RR and CS
soybean grew, as well as surrounding NV. All RR fields have been treated with glyphosate
for no less than five years. Microbial community structures of the twenty three sites in the
RR, CS and NV ecosystems were determined by phospholipid fatty acid (PLFA) analyses.
Nematode diversity was determined by extracting the nematodes from soil samples and
conducting a faunal analysis. Soil physical and chemical properties were determined by an
independent laboratory, Eco-Analytica (North West University, Potchefstroom) according to
standard procedures.
Results from this study indicated differences in microbial community structure between the
various localities. However, there were no significant (p ≤ 0.05) differences in microbial
community structures between RR- and CS ecosystems. Soils of both RR- and CS crops
were primarily dominated by bacteria. Nematode identification and faunal analysis also
indicated no significant (p ≤ 0.05) differences between the different non-parasitic/beneficial
nematodes that were present in soils of these two ecosystems during the time of sampling.
Non-parasitic nematode communities were primarily dominated by bacterivores. A faunal
analysis indicated that most of the sites contained enriched, but unstructured soil food-webs.
However, four of the sites showed enriched and structured food webs due to the presence of
non-parasitic nematodes with high coloniser-persister (cp) values. Relationships between non-parasitic nematode – and microbial communities showed that there was a positive
relationship between nematode functional groups and their corresponding microbial prey.
From the results obtained in this study, it can be concluded that the community structures of
both non-parasitic nematodes and microorganisms shared similarities. These community
structures showed no long-term detrimental effects of glyphosate application in the soils
surrounding roots of RR soybean crops. Relationships existed between non-parasitic
nematode and microbial communities in the rhizosphere of soybean crops and natural veld.
For example, bacterivore nematodes had a strong positive relationship with gram-negative
bacteria. Similar but weaker relationships also existed between carnivores, omnivores, plantparasitic
nematodes and gram-negative bacteria. A positive relationship also existed
between fungivores and fungal fatty acids. This emphasises the value of these organisms as
indicators of soil health and also the impact that agricultural practices can have on soils. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
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Incidence de la réglementation actuelle et future des aliments génétiquement modifiés sur leur exploitationPersico, Nancy 12 1900 (has links)
"Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de Maître en droit (LL.M)" / Depuis quelques années, le recours à la biotechnologie dans le secteur de
l'alimentation est omniprésent. Les techniques, évoluant au gré de l'avancement
de la science, permettent aux gens faisant partie de plusieurs sphères de la
société, tels les scientifiques, producteurs, agriculteurs, consommateurs etc., de
profiter de ces percées technologiques. Toutefois, afin d'encadrer la
commercialisation de ces nouveaux produits alimentaires découlant de cette
technologie, un cadre réglementaire devait, il va sans dire, être élaboré. Ce fut le
cas de part et d'autre de l'Atlantique. Toutefois, bien qu'appréciée des
scientifiques, cette technologie est loin de faire l'assentiment de tous. D'ailleurs,
différentes perceptions se reflètent dans les différents cadres réglementaires mis
de l'avant, tout aussi bien canadien que français, quant à l'utilisation et la mise en
vente des nouveaux aliments. Ce travail décrit les systèmes réglementaires visant
la commercialisation des aliments nouveaux tant canadien que français. Par
ailleurs, il relate les différents débats, sociologique, éthique, et techniques, dont
ces organismes génétiquement modifiés (OGM) sont la cible. / Since the past decades, the use of biotechnology in the industry of novel food was
very considerable. This new technique is very useful, and can be easily important
for an appreciable quantity of people, like productors, agricultors and consumers.
Since it was used in the production of novel food, a new regulatory enforcement
was needed. It was done either in France and Canada, but differently. As we
know, the different way of life in both countries play an important role in the
acceptance of the genetically modified organisms (GMO's). In this thesis, we
will give a description of the different regulatory frameworks for food products of
biotechnology. Then, we will see what was important, according to the different
sociologie and ethics point of view, in the elaboration of these relevant
legislation.
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ENGINEERING GENETICALLY ENCODED FLUORESCENT BIOSENSORS TO STUDY THE ROLE OF MITOCHONDRIAL DYSFUNCTION AND INFLAMMATION IN PARKINSON’S DISEASEStevie Norcross (6395171) 10 June 2019 (has links)
<p>Parkinson’s disease is a neurodegenerative disorder
characterized by a loss of dopaminergic neurons, where mitochondrial
dysfunction and neuroinflammation are implicated in this process. However, the
exact mechanisms of mitochondrial dysfunction, oxidative stress and
neuroinflammation leading to the onset and development of Parkinson’s disease
are not well understood. There is a lack of tools necessary to dissect these
mechanisms, therefore we engineered genetically encoded fluorescent biosensors
to monitor redox status and an inflammatory signal peptide with high
spatiotemporal resolution. To measure intracellular redox dynamics, we
developed red-shifted redox sensors and demonstrated their application in dual
compartment imaging to study cross compartmental redox dynamics in live cells.
To monitor extracellular inflammatory events, we developed a family of
spectrally diverse genetically encoded fluorescent biosensors for the
inflammatory mediator peptide, bradykinin. At the organismal level, we characterized the locomotor effects of mitochondrial toxicant-induced
dopaminergic disruption in a zebrafish animal model and evaluated a behavioral
assay as a method to screen for dopaminergic dysfunction. Pairing our
intracellular redox sensors and our extracellular bradykinin sensors in a
Parkinson’s disease animal model, such as a zebrafish toxicant-induced model will
prove useful for dissecting the role of mitochondrial dysfunction and
inflammation in Parkinson’s disease. </p>
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Plant as bioreactor: transgenic expression of malaria surface antigen in plants.January 2001 (has links)
by Ng Wang Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 131-139). / Abstracts in English and Chinese. / Acknowledgements --- p.iii / Abstract --- p.v / List of Tables --- p.ix / List of Figures --- p.x / List of Abbreviations --- p.xiii / Table of Contents --- p.xv / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter Chapter 2: --- Literature Review --- p.3 / Chapter 2.1 --- Malaria --- p.3 / Chapter 2.1.1 --- Global picture --- p.3 / Chapter 2.1.2 --- Malaria mechanics --- p.4 / Chapter 2.1.3 --- Life cycle of malaria parasite --- p.4 / Chapter 2.2 --- Treatment of malaria ´ؤ malaria drugs --- p.5 / Chapter 2.2.1 --- Antimalarial drugs --- p.5 / Chapter 2.2.2 --- Drug resistance --- p.6 / Chapter 2.3 --- Treatment of malaria - malarial vaccines --- p.7 / Chapter 2.3.1 --- Malarial vaccine developments --- p.7 / Chapter 2.3.2 --- Transmission blocking vaccines --- p.7 / Chapter 2.3.3 --- Pre-erythrocytic vaccines --- p.9 / Chapter 2.3.4 --- Blood stage vaccines --- p.10 / Chapter 2.4 --- The major merozoite protein - gpl95 --- p.11 / Chapter 2.5 --- Plants as bioreactors --- p.12 / Chapter 2.5.1 --- Products of transgenic plants --- p.13 / Chapter 2.6 --- Transgenic plants for production of subunit vaccines --- p.14 / Chapter 2.6.1 --- Norwalk virus capsid protein production --- p.15 / Chapter 2.6.2 --- Hepatitis B surface antigen production --- p.15 / Chapter 2.7 --- Tobacco and Arabidopsis as model plants --- p.16 / Chapter 2.7.1 --- Arabidopsis --- p.16 / Chapter 2.7.2 --- Tobacco --- p.17 / Chapter 2.8 --- Transformation methods --- p.17 / Chapter 2.8.1 --- Direct DNA uptake --- p.17 / Chapter 2.8.1.1 --- Plant protoplast transformation --- p.17 / Chapter 2.8.1.2 --- Biolistic transformation --- p.18 / Chapter 2.8.2 --- Agrobacterium-mediated transformation --- p.18 / Chapter 2.8.2.1 --- Leaf-disc technique --- p.18 / Chapter 2.8.2.2 --- In planta transformation --- p.19 / Chapter 2.9 --- Phaseolin --- p.20 / Chapter 2.10 --- Detection and purification of recombinant products - Histidine tag --- p.21 / Chapter 2.11 --- Aims of study and hypotheses --- p.22 / Chapter Chapter 3: --- Materials and Methods --- p.24 / Chapter 3.1 --- Introduction --- p.24 / Chapter 3.2 --- Chemicals --- p.24 / Chapter 3.3 --- Expression in tobacco system --- p.24 / Chapter 3.3.1 --- Plant materials --- p.24 / Chapter 3.3.2 --- Bacterial strains --- p.25 / Chapter 3.3.3 --- Chimeric gene construction for tobacco transformation --- p.25 / Chapter 3.3.3.1 --- The cloning of pTZPhasp/flgp42-His/Phast (F1) --- p.26 / Chapter 3.3.3.2 --- The cloning of pBKPhasp-sp/flgp42-His/Phast (P9) --- p.30 / Chapter 3.3.3.3 --- The cloning of pHM2Ubip/flgp42-His/Nost (C2) --- p.30 / Chapter 3.3.4 --- Confirmation of sequence fidelity of chimeric gene by DNA sequencing --- p.33 / Chapter 3.3.5 --- Cloning of chimeric gene into binary vector --- p.34 / Chapter 3.3.6 --- Triparental mating of Agrobacterium tumefaciens LBA4404/pAL4404 --- p.35 / Chapter 3.3.7 --- Tobacco transformation and regeneration --- p.36 / Chapter 3.3.8 --- GUS assay --- p.37 / Chapter 3.3.9 --- Genomic DNA isolation --- p.37 / Chapter 3.3.10 --- PCR amplification and detection of transgene --- p.38 / Chapter 3.3.11 --- Southern blot analysis --- p.38 / Chapter 3.3.12 --- Total seeds RNA isolation --- p.39 / Chapter 3.3.13 --- RT-PCR --- p.39 / Chapter 3.3.14 --- Northern blot analysis --- p.40 / Chapter 3.3.15 --- Protein extraction and SDS-PAGE --- p.40 / Chapter 3.3.16 --- Western blot analysis --- p.41 / Chapter 3.4 --- Expression in Arabidopsis system --- p.42 / Chapter 3.4.1 --- Plant materials --- p.42 / Chapter 3.4.2 --- Bacterial strains --- p.42 / Chapter 3.4.3 --- Chimeric gene construction --- p.42 / Chapter 3.4.3.1 --- The cloning of pBKPhasp-sp/His/EK/p42/Phast (DH) --- p.43 / Chapter 3.4.3.2 --- The cloning of pTZPhaSp/His/EK/p42/Phast (EH) --- p.45 / Chapter 3.4.3.3 --- The cloning of pBKPhasp-sp/His/EK/flgp42/Phast (DHF) and pTZPhasp/His/EK/flgp42/Phast (EHF) --- p.45 / Chapter 3.4.4 --- Confirmation of sequence fidelity of chimeric genes --- p.45 / Chapter 3.4.5 --- Cloning of chimeric gene into Agrobacterium binary vector --- p.49 / Chapter 3.4.6 --- Transformation of Agrobacterium tumefaciens GV3101/pMP90 with chimeric gene constructs --- p.49 / Chapter 3.4.7 --- Arabidopsis Transformation --- p.49 / Chapter 3.4.8 --- Vacuum infiltration transformation --- p.50 / Chapter 3.4.9 --- Selection of successful transformants --- p.51 / Chapter 3.4.10 --- Selection for homozygous plants with single gene insertion --- p.51 / Chapter 3.4.11 --- GUS assay --- p.52 / Chapter 3.4.12 --- Genomic DNA isolation --- p.52 / Chapter 3.4.13 --- PCR amplification and detection of transgenes --- p.52 / Chapter 3.4.14 --- Southern Blot analysis --- p.52 / Chapter 3.4.15 --- Total siliques RNA isolation --- p.53 / Chapter 3.4.16 --- RT-PCR --- p.53 / Chapter 3.4.17 --- Northern blot analysis --- p.53 / Chapter 3.4.17 --- Protein extraction and SDS-PAGE --- p.54 / Chapter 3.4.18 --- Western blot analysis --- p.54 / Chapter 3.5 --- In vitro transcription and translation --- p.54 / Chapter 3.5.1 --- In vitro transcription --- p.54 / Chapter 3.5.2 --- In vitro translation --- p.55 / Chapter 3.6 --- Particle bombardment of GUS fusion gene --- p.56 / Chapter 3.6.1 --- Chimeric gene constructs --- p.56 / Chapter 3.6.2 --- Particle bombardment using snow bean cotyledon --- p.61 / Chapter Chapter 4: --- Results --- p.63 / Chapter 4.1 --- Tobacco system --- p.63 / Chapter 4.1.1 --- Chimeric gene constructs --- p.63 / Chapter 4.1.2 --- Tobacco transformation and regeneration --- p.65 / Chapter 4.1.3 --- GUS activity assay --- p.67 / Chapter 4.1.4 --- Molecular analysis of transgene integration --- p.68 / Chapter 4.1.4.1 --- Genomic DNA extraction and PCR --- p.68 / Chapter 4.1.4.2 --- Southern blot analysis --- p.70 / Chapter 4.1.5 --- Molecular analysis of transgene expression --- p.72 / Chapter 4.1.5.1 --- Total RNA isolation and RT-PCR --- p.72 / Chapter 4.1.5.2 --- Northern blot analysis --- p.75 / Chapter 4.1.6 --- Genomic PCR to confirm whole gene transfer --- p.76 / Chapter 4.1.7 --- Biochemical analysis of transgene expression --- p.78 / Chapter 4.1.7.1 --- Protein extraction and SDS-PAGE --- p.78 / Chapter 4.1.7.2 --- Western blot analysis --- p.78 / Chapter 4.2 --- Arabidopsis system --- p.83 / Chapter 4.2.1 --- Chimeric gene constructs --- p.83 / Chapter 4.2.2 --- Arabidopsis transformation and selection --- p.85 / Chapter 4.2.3 --- Selection of transgenic plants --- p.87 / Chapter 4.2.4 --- Assay of GUS activity --- p.91 / Chapter 4.2.5 --- Molecular analysis of transgene integration --- p.92 / Chapter 4.2.5.1 --- Genomic DNA extraction and PCR --- p.92 / Chapter 4.2.5.2 --- Southern blot analysis --- p.96 / Chapter 4.2.6 --- Molecular analysis of transgene expression --- p.99 / Chapter 4.2.6.1 --- Total RNA isolation and RT-PCR --- p.99 / Chapter 4.2.6.2 --- Northern blot analysis --- p.106 / Chapter 4.2.7 --- Genomic PCR for confirmation of whole gene transfer --- p.107 / Chapter 4.2.8 --- Biochemical analysis of transgene expression --- p.108 / Chapter 4.2.8.1 --- Protein extraction and SDS-PAGE --- p.108 / Chapter 4.2.8.2 --- Western blot analysis --- p.108 / Chapter 4.3 --- In vitro transcription and translation --- p.112 / Chapter 4.4 --- Particle bombardment of p42/ GUS fusion gene --- p.115 / Chapter Chapter 5: --- Discussion and Future perspectives --- p.117 / Chapter 5.1 --- Failure in detecting transgene expression --- p.117 / Chapter 5.2 --- Poor transgene expression --- p.120 / Chapter 5.2.1 --- Bacillus thuringiensis toxin and green fluorescent protein --- p.120 / Chapter 5.2.2 --- AT-richness --- p.121 / Chapter 5.2.3 --- Deleterious sequence - AUUUA --- p.123 / Chapter 5.2.4 --- Presence of AAUAAA or AAUAAA-like motifs --- p.125 / Chapter 5.2.5 --- Codon usage --- p.126 / Chapter 5.3 --- Future perspectives --- p.127 / Chapter Chapter 6: --- Conclusion --- p.129 / References --- p.131
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INTERAÇÕES ENTRE LEPIDÓPTEROS-PRAGA DA SOJA E ENTOMOPATÓGENOS, COM ÊNFASE EM BACILLUS THURINGIENSIS QUE EXPRESSA A PROTEÍNA CRY1ACWisch, Lucas Nataniel 26 February 2016 (has links)
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Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soybean is the main crop of economic importance and commercially produced on a large scale in Brazil. Nevertheless many are the factors that affect the productive potential of this oilseed, among them stand out the insects of the order Lepidoptera. As an alternative to control these pests, many growers have adopted the use of Bt soybean, which expresses the Cry1Ac toxin. However, the large area with this technology can generates a main concern that is Cry1Ac exposure to target and non-target insects and its entomopathogens, such Metarhizium rileyi and nuclear polyhedrosis virus. The aim of this study were to elucidate the HD-73 impacts, that expresses Cry1Ac, i) in the immune system of S. frugiperda in order to investigate whether Bt challenge parental induce "immune priming or transgenerational effects"; ii) on virulence and occlusion body yield in Spodoptera frugiperda iii) level of larval mortality of the noctuid species when applied simultaneously or sequentially with NPV and M. rileyi; and iv) the biological parameters of the noctuid species, when exposed in conjunction with entomopathogens. In the immune assay, neonate larvae were exposed ad libitum to different concentrations of HD-73 (0, 15, 33, 72.6 μg.ml-1), in the fifth instar were extracted the haemolymph and measured the number of haemocytes, total protein and phenoloxidase activity (PO). Neonate offspring of those individuals were inoculated with 0 and 40 μg.ml-1 of HD-73 and again was quantified the same immune components in fifth instar larvae, including antibacteriana activity. In addition, biological parameters were observed in these tests. In the evaluation of Cry1Ac impacts on virus infectivity in S. frugiperda, neonate were exposed to HD-73 (0, 10, 40 and 80 μg.ml-1) until the end of the third instar and early of the fourth instar was inoculated with viruses (0, 103 and 104 OB.larvae-1). For this assay was evaluated larval weight (4 DAE), mortality, number of OB/caterpillar and subsequently, virulence test (LC50). Spodoptera cosmioides, Spodoptera eridania, S. frugiperda, Chrysodeixis includens and Rachiplusia nu caterpillars were simultaneously or sequentially exposed to entomopathogens, HD-73, M. rileyi and their viruses, and record mortality and biological parameters of these interactions. The sublethal concentrations of HD-73 did not cause changes in the immune system of the parental, as well as there was no evidence for acquired immunity in the offspring. Sublethal concentration of HD-73 affected the biological components of S. frugiperda, providing lower larval and pupal weight, reduced fecundity and egg viability. HD-73 proved lower OB yield/caterpillar and lower virulence of the virus multiplied in caterpillars prior exposed to 10 μg.ml-1. The interactions did not affect the biological parameters of these noctuids. In most cases was observed negative effect in the interactions between HD-73 and viruses, but may be promising simultaneous inoculation of HD-73 and M. rileyi to control S. eridania and S. frugiperda. Sublethal concentrations of HD-73 did not provide larger mortality of Plusiinae in interactions with M. rileyi and viruses, except for HD-73+ M. rileyi that had positive and negative effects on C. includens. / A soja é a principal cultura de importância econômica e comercialmente produzida em larga escala no Brasil. Porém, diversos são os fatores que afetam o potencial produtivo desta oleaginosa, entre eles destacam-se os insetos da ordem Lepidoptera. Como alternativa para controle destas pragas, diversos produtores têm adotado o uso da soja Bt, que expressa a toxina Cry1Ac. Contudo, a expansão da área com essa tecnologia gera dúvidas quanto ao impacto da exposição de Cry1Ac aos insetos-alvo e não-alvo e seus entomopatógenos, Metarhizium rileyi e os vírus de poliedrose nuclear. Assim, os objetivos desse trabalho foram: elucidar o impacto de concentrações subletais da cepa HD-73, que expressa Cry1Ac, i) no sistema imunológico de Spodoptera frugiperda, a fim de investigar se o desafio com Bt induz a “memória imunológica”; ii) na virulência e produção de corpos de oclusão do vírus em S. frugiperda; iii) na mortalidade larval das espécies de noctuídeos, quando aplicada de forma simultânea ou sequencial com VPN e M. rileyi; e iv) nos parâmetros biológicos de noctuídeos-alvo e não-alvo, quando aplicada em conjunto com os entomopatógenos. No ensaio imunológico, lagartas neonatas foram expostas ad libitum a diferentes concentrações de HD-73 (0, 15, 33, 72,6 μg.ml-1), no quinto instar foi extraída a hemolinfa e avaliado o número de hemócitos, proteína total e atividade da fenoloxidase (PO). Neonatas descendentes destes indivíduos foram inoculadas com 0 e 40 μg.ml-1 de HD-73 e no quinto instar quantificou-se os mesmos componentes de resposta imune observados nos parentais, incluindo a atividade antibacteriana. Os parâmetros biológicos também foram observados nestes ensaios. Nas avaliações do impacto de Cry1Ac na infectividade de vírus sobre S. frugiperda, neonatas foram inoculadas com HD-73 (0, 10, 40 e 80 μg.ml-1) e mantidas até o final do terceiro instar, e no início do quarto instar ocorreu a infecção com vírus (0, 103 e 104 CO.lagarta-1), após foi avaliado o peso larval (4 DAE), a mortalidade, o número de CO.cadáver-1 e, posteriormente, teste de virulência (CL50). Lagartas de Spodoptera cosmioides, Spodoptera eridania, S. frugiperda, Chrysodeixis includens e Rachiplusia nu, foram expostas de forma simultânea ou sequencial aos entomopatógenos, HD-73, M. rileyi e os respectivos vírus, para registrar a mortalidade e os parâmetros biológicos destas interações. As concentrações subletais de HD-73 não provocaram alterações no sistema imune dos parentais, como também não houve evidências de imunidade adquirida nas progênies. HD-73 afetou subletalmente os componentes biológicos de S. frugiperda, proporcionando menor peso larval e pupal, redução na fecundidade e viabilidade dos ovos. HD-73 proporcionou menor rendimento de CO.cadáver-1 e menor virulência dos vírus multiplicados em lagartas expostas a 10 μg.ml-1. As interações não afetaram os parâmetros biológicos dos noctuídeos em estudo. Na maioria dos casos observou-se efeito negativo nas interações entre HD-73 e vírus, mas podendo ser promissor a inoculação simultânea de HD-73 e M. rileyi no controle de S. eridania e S. frugiperda. Concentrações subletais de HD-73 não proporcionaram maior mortalidade das Plusiinae nas interações com M. rileyi e vírus, exceto na associação HD-73+M. rileyi que apresentou efeitos positivos e negativos sobre C. includens.
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