Building an Artificial Stem Cell Niche: Prerequisites for Future 3D-Formation of Inner Ear Structures—Toward 3D Inner Ear Biotechnology
Groot, Simon C. de; Sliedregt, Karen ; Benthem, Peter Paul G. van; Rivolta, Marcelo N. ; Huisman, Margriet A. - \ 2020
The Anatomical Record 303 (2020)3. - ISSN 1932-8486 - p. 408 - 426.
3D - biotechnology - inner ear - stem cell
In recent years, there has been an increased interest in stem cells for the purpose of regenerative medicine to deliver a wide range of therapies to treat many diseases. However, two-dimensional cultures of stem cells are of limited use when studying the mechanism of pathogenesis of diseases and the feasibility of a treatment. Therefore, research is focusing on the strengths of stem cells in the three-dimensional (3D) structures mimicking organs, that is, organoids, or organ-on-chip, for modeling human biology and disease. As 3D technology advances, it is necessary to know which signals stem cells need to multiply and differentiate into complex structures. This holds especially true for the complex 3D structure of the inner ear. Recent work suggests that although other factors play a role, the extracellular matrix (ECM), including its topography, is crucial to mimic a stem cell niche in vitro and to drive stem cells toward the formation of the tissue of interest. Technological developments have led to the investigation of biomaterials that closely resemble the native ECM. In the fast forward moving research of organoids and organs-on-chip, the inner ear has hardly received attention. This review aims to provide an overview, by describing the general context in which cells, matrix and morphogens cooperate in order to build a tissue, to facilitate research in 3D inner ear technology. Anat Rec, 2019.
The effects of an online learning environment with worked examples and peer feedback on students’ argumentative essay writing and domain-specific knowledge acquisition in the field of biotechnology
Valero Haro, Anahuac ; Noroozi, Omid ; Biemans, Harm J.A. ; Mulder, Martin - \ 2019
Journal of Biological Education 53 (2019)4. - ISSN 0021-9266 - p. 390 - 398.
biotechnology - Essay writing - example-based learning - online learning environment - peer feedback
The present study investigated the effects of an online learning environment supported with worked examples and peer feedback on students’ argumentative essay writing and domain-specific knowledge acquisition in the field of biotechnology. As part of a bigger project, a pre- and post-test study design was used with 45 bachelor students who were randomly grouped in pairs. Students were asked to analyse a case and write an argumentative essay taking into account the advantages and disadvantages of genetically modified organisms. The results showed that the combination of worked examples and peer feedback improve the quality of argumentative essay writing and facilitate the acquisition of domain-specific knowledge. Implications, suggestions, and future research are discussed.
Schimmel kan efficiënt melkzuur maken: Vinding van Wageningen Universiteit Research (WUR)
Eggink, Gerrit ; Weusthuis, Ruud - \ 2017
biobased chemistry - biobased economy - biotechnology - ethanol - bioenergy - lactic acid
Metabolic modeling to understand and redesign microbial systems
Heck, Ruben G.A. van - \ 2017
Wageningen University. Promotor(en): V.A.P. Martins dos Santos, co-promotor(en): M. Suárez Diez. - Wageningen : Wageningen University - ISBN 9789463434553 - 239
micro-organismen - modelleren - kooldioxide - biotechnologie - algen - metabolisme - pseudomonas - microorganisms - modeling - carbon dioxide - biotechnology - algae - metabolism - pseudomonas
The goals of this thesis are to increase the understanding of microbial metabolism and to functionally (re-)design microbial systems using Genome- Scale Metabolic models (GSMs). GSMs are species-specific knowledge repositories that can be used to predict metabolic activities for wildtype and genetically modified organisms. Chapter 1 describes the assumptions associated with GSMs, the GSM generation process, common GSM analysis methods, and GSM-driven strain design methods. Thereby, chapter 1 provides a background for all other chapters. In this work, there is a focus on the metabolically versatile bacterium Pseudomonas putida (chapters 2,3,4,5,6), but also other model microbes and biotechnologically or societally relevant microbes are considered (chapters 3,4,6,7,8).
GSMs are reflections of the genome annotation of the corresponding organism. For P. putida, the genome annotation that GSMs have been built on is more than ten years old. In chapter 2, this genome annotation was updated both on a structural and functional level using state-of-the-art annotation tools. A crucial part of the functional annotation relied on the most comprehensive P. putida GSM to date. This GSM was used to identify knowledge gaps in P. putida metabolism by determining the inconsistencies between its growth predictions and experimental measurements. Inconsistencies were found for 120 compounds that could be degraded by P. putida in vitro but not in silico. These compounds formed the basis for a targeted manual annotation process. Ultimately, suitable degradation pathways were identified for 86/120 as part of the functional reannotation of the P. putida genome.
For P. putida there are 3 independently generated GSMs, which is not uncommon for model organisms. These GSMs differ in generation procedure and represent different and complementary subsets of the knowledge on the metabolism of the organism. However, the differing generation procedures also makes it extremely cumbersome to compare their contents, let alone to combine them into a single consensus GSM. Chapter 3 addresses this issue through the introduction of a computational tool for COnsensus Metabolic Model GENeration (COMMGEN). COMMGEN automatically identifies inconsistencies between independently generated GSMs and semi-automatically resolves them. Thereby, it greatly facilitates a detailed comparison of independently generated GSMs as well as the construction of consensus GSMs that more comprehensively describe the knowledge on the modeled organism.
GSMs can predict whether or not the corresponding organism and derived mutants can grow in a large variety of different growth conditions. In comparison, experimental data is extremely limited. For example, BIOLOG data describes growth phenotypes for one strain in a few hundred different media, and genome-wide gene essentially data is typically limited to a single growth medium. In chapter 4 GSMs of multiple Pseudomonas species were used to predict growth phenotypes for all possible single-gene-deletion mutants in all possible minimal growth media to determine conditionally and unconditionally essential genes. This simulated data was integrated with genomic data on 432 sequenced Pseudomonas species, which revealed a clear link between the essentiality of a gene function and the persistence of the gene within the Pseudomonas genus.
Chapters 5 and 6 describe the use of GSMs to (re-)design microbial systems. P. putida is, despite its acknowledged versatile metabolism, an obligate aerobe. As the oxygen-requirement limits the potential applications of P. putida, there have been several experimental attempts to enable it to grow anaerobically, which have so far not succeeded. Chapter 5 describes an in silico effort to determine why P. putida cannot grow anaerobically using a combination of GSM analyses and comparative genomics. These analyses resulted in a shortlist of several essential and oxygen-dependent processes in P. putida. The identification of these processes has enabled the design of P. putida strains that can grow anaerobically based on the current understanding of P. putida metabolism as represented in GSMs.
Efficient microbial CO2 fixation is a requirement for the biobased community, but the natural CO2 fixation pathways are rather inefficient, while the synthetic CO2 fixation pathways have been designed without considering the metabolic context of a target organism. Chapter 6 introduces a computational tool, CO2FIX, that designs species-specific CO2 fixation pathways based on GSMs and biochemical reaction databases. The designed pathways are evaluated for their ATP efficiency, thermodynamic feasibility, and kinetic rates. CO2FIX is applied to eight different organisms, which has led to the identification of both species-specific and general CO2 fixation pathways that have promising features while requiring surprisingly few non-native reactions. Three of these pathways are described in detail.
In all previous chapters GSMs of relatively well-understood microbes have been used to gain further insight into their metabolism and to functionally (re-)design them. For complex microbial systems, such as algae (chapter 7) and gut microbial communities (chapter 8), GSMs are similarly useful, but substantially more difficult to create and analyze. Algae are widely considered as potential centerpieces of a biobased economy. Chapter 7 reviews the current challenges in algal genome annotation, modeling and synthetic biology. The gut microbiota is an incredibly complex microbial system that is crucial to our well-being. Chapter 8 reviews the ongoing developments in the modeling of both single gut microbes and gut microbial communities, and discusses how these developments will enable the move from studying correlation to causation, and ultimately the rational steering of gut microbial activity.
Chapter 9 discusses how the previous chapters contribute to the research goals of this thesis. In addition, it provides an extensive discussion on current GSM practices, the issues associated therewith, and how these issues can be tackled. In particular, the discussion focuses on issues related to: (i) The inability to distinguish between biological difference and GSM generation artifacts when using multiple GSMs, (ii) The lack of continuous GSM updates, (iii) The mismatch between what GSM predictions and experimental data represent, (iv) The need for standardization in GSM evaluation, and (v) The lack of experimental validation of GSM-driven strain design for metabolic engineering.
Toekomst AlgaePARC veiliggesteld
Barbosa, Maria - \ 2017
algae - algae culture - bioprocess engineering - biotechnology - experimental stations - research projects - test rigs - financing
AlgaePARC, de Wageningse proefaccommodatie voor algenonderzoek, kan voorlopig weer vooruit. Onderzoeker Maria Barbosa van Bioprocestechnologie haalde vier onderzoeksprojecten binnen, waaronder een groot EU-project.
Planten nabootsen : onderzoek naar fotosynthese gaat vruchten afwerpen
Klein Lankhorst, Rene ; Aarts, Mark ; Amerongen, Herbert van - \ 2016
biobased economy - biobased chemistry - biofuels - photosynthesis - biotechnology - biobased chemicals - energy sources - solar energy - renewable energy - techniques
Planten zijn meesters in het gebruik van zonlicht. Daarmee zetten ze water en kooldioxide om in suikers en zuurstof. Wageningse onderzoekers kunnen dit proces nabootsen en verbeteren. Zo willen ze biobrandstoffen maken en beter groeiende gewassen
Kennisagenda biomimicry 2015-2018
Vogelzang, T.A. ; Vader, J. ; Michels, R. - \ 2016
Den Haag : Wageningen Economic Research - 23
biobased economy - ontwerp - innovaties - biomimicry - duurzame ontwikkeling - productontwikkeling - biotechnologie - kennismanagement - gebiedsontwikkeling - organisatieontwikkeling - biobased economy - design - innovations - biomimicry - sustainable development - product development - biotechnology - knowledge management - area development - organizational development
Biomimicry , de ontwerpfilosofie die de natuur als inspiratiebron ziet voor innovaties, kan grote ecologische en economische voordelen opleveren voor onze samenleving wanneer het bre ed wordt ingezet ten behoeve van maatschappelijke en wetenschappelijke vraagstukken. Het biedt ook veel toepassingsmogelijkheden voor een groot aantal sectoren , zoals bouw, industrie en landbouw . Om aan een kennisinfrastructuur voor biomimicry te kunn en werken, is het van belang om te weten welke kennis diverse partijen in ons land in huis hebben, welke ze willen delen en welke kennislacunes er zijn. Deze kennisagenda is met dat doel opgesteld. De kennisagenda agendeert een aantal vraagstukken voor de komende periode waaraan betrokken stakeholders in onderlinge samenwerking gericht kunnen werken om de toepassing van biomimicry in ons land de komende jaren op een hog er plan te brengen. Deze kennisagenda geeft daarmee richting aan biomimicry -innovaties die de komende jaren (wellicht) met voorrang opgepakt worden.
Starch meets biotechnology : in planta modification of starch composition and functionalities
Xu, Xuan - \ 2016
Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Luisa Trindade. - Wageningen : Wageningen University - ISBN 9789462579200 - 169
starch - potato starch - potatoes - solanum tuberosum - plant biotechnology - biotechnology - genetic engineering - transgenic plants - modified starches - phosphate - arabidopsis thaliana - plant breeding - zetmeel - aardappelzetmeel - aardappelen - solanum tuberosum - plantenbiotechnologie - biotechnologie - genetische modificatie - transgene planten - gemodificeerd zetmeel - fosfaat - arabidopsis thaliana - plantenveredeling
Storage starch is an energy reservoir for plants and the major source of calories in the human diet. Starch is used in a broad range of industrial applications, as a cheap, abundant, renewable and biodegradable biopolymer. However, starch needs to be modified before it can fulfill the required properties for specific industrial applications. Genetic modification of starch, as a green technology with environmental and economic advantages, has attracted increasingly attention. Many achievements obtained from earlier studies have demonstrated the feasibility and potential of using this approach to produce starches with novel properties (Chapter 2).
The main objective of this research was to produce novel starches with enhanced functionalities through genetic modification, while gaining a better understanding of storage starch biosynthesis. A focus on potato was warranted as it represents a superior model system for storage starch biosynthesis studies and for the production of starches with novel properties. To this end, a number of enzymes from various sources have been expressed in potato tubers to modify starch phosphate content and polysaccharide structure, since these two characteristics have long been recognized as key features in starch properties.
To modify starch phosphate content and explore starch (de)phosphorylation, a human phosphatase enzyme named laforin, and modifications of it, were introduced into potato (Chapter 3). Interestingly, modified starches exhibited a significantly higher phosphate content rather than the expected lower phosphate content. Transcriptome analysis showed that the increase in phosphate content was a result of upregulation of starch phosphorylating genes, which revealed a compensatory response to the loss of phosphate content in potato starch. Furthermore, the increase of phosphate content in potato starch was reached to a threshold level. This was in line with the observations in the modified starches from overexpressed- Glucan water dikinase (GWD1) transgenic plants (Chapter 4). Furthermore, overexpression of two starch dikinases from Arabidopsis thaliana, glucan water dikinase 2 and 3 (AtGWD2 and AtGWD3), did not result in a significant increase in phosphate content of potato starch (Chapter 5). Taken together, these results indicated that phosphate content of potato starch is under strict control.
Morphological analysis of starch granules containing different levels of phosphate content confirmed the indispensible role of phosphate content in the normal formation of starch granules, since cracked granules were observed in the starches containing low phosphate content, while irregular bumpy shaped granules were observed in the tubers from plants containing high phosphate content. Interestingly, further analyses on the expression level of genes involved in starch metabolism and sugar-starch conversion suggested that starch phosphorylation might affect starch synthesis by controlling the carbon flux into starch while simultaneously modulating starch-synthesizing genes. Further studies are needed to confirm this finding (Chapter 4).
To produce starches with novel structures, an (engineered) 4, 6-α-glucanotransferase (GTFB) from Lactobacillus reuteri 121 was introduced into potato tubers (Chapter 6). The resulting starches showed severe changes in granule morphology, but not in starch fine structure. Transcriptome analysis revealed the existence of a self-repair mechanism to restore the regular packing of double helices in starch granules, which possibly resulted in the removal of novel glucose chains potentially introduced by the (engineered) GTFB.
This research successfully generated starches with various functionalities, including altered gelatinization characteristics (Chapter 3 and 4), improved freeze-thaw stability (Chapter 4) and higher digestibility (Chapter 6). The exploitation of relationships between starch characteristics and starch properties revealed that starch properties represent the outcome of the combined effect of many factors and are highly dependent on the genetic background in which the modification has been performed.
In conclusion, the research described in this thesis demonstrates the great potential of genetic modification in producing starches with novel properties. Meanwhile, these results revealed the presence of complex and exquisite molecular regulation mechanisms for starch biosynthesis in potato. In future research, these regulations need to be taken into account for the relational design of starch in planta. Certainly, a better understanding of the process of starch metabolism in storage organs would be a great step forward towards tailoring starch in an economically important crop such as potato.
Next-generation salmonid alphavirus vaccine development
Hikke, M.C. - \ 2016
Wageningen University. Promotor(en): Just Vlak, co-promotor(en): Gorben Pijlman. - Wageningen : Wageningen University - ISBN 9789462577404 - 159
alphavirus - atlantic salmon - rainbow trout - vaccine development - immunity - virology - fish culture - aquaculture - biotechnology - alfavirus - europese zalm - regenboogforel - vaccinontwikkeling - immuniteit - virologie - visteelt - aquacultuur - biotechnologie
Aquaculture is essential to meet the current and future demands for seafood to feed the world population. Atlantic salmon and rainbow trout are two of the most cultured aquaculture species. A pathogen that threatens these species is salmonid alphavirus (SAV). A current inactivated virus vaccine against SAV provides cross-protection against all SAV subtypes in salmonids and reduces mortality amongst infected fish. However, protection is not 100% and due to virus growth at low temperature, the vaccine production process is time consuming. In addition, the vaccine needs to be injected into the fish, which is a cumbersome process. The work described in this thesis aimed to increase the general knowledge of SAV and to assess current vaccine technologies, and to use this knowledge in designing next-generation vaccines for salmonid aquaculture.
An alternative cell line to support SAV proliferation was identified, however, the virus production time could not yet outcompete the current SAV production system. Making use of the baculovirus insect cell expression system, multiple enveloped virus-like particle (eVLP), and core-like particle (CLP) prototype vaccines were produced in insect cells at high temperature. An in vivo vaccination study showed, however, that these vaccines could not readily protect Atlantic salmon against SAV. The low temperature-dependent replication of SAV was attributed to the glycoprotein E2, and it was found that E2 only correctly travelled to the cell surface at low temperature, and in the presence of glycoprotein E1. The biological impact of this finding was confirmed in the development and in vivo testing of a DNA-launched replicon vaccine. The effective DNA-launched replicon vaccine was extended by delivery of the capsid protein in trans. It was hypothesized that viral replicon particles (VRP) were formed in vivo, which would cause an additional single round of infection and might further elevate the immune response in comparison to the replicon vaccine. A second animal trial indicated that the inclusion of capsid did not yet improve vaccine efficacy. This trial however did show that a DNA vaccine transiently expressing the SAV structural proteins provided superior protection over both replicon vaccines (with and without capsid).
In this thesis, some virus characteristics, such as the cause of temperature-dependency of SAV replication, of an unique aquatic virus were further explored. The production and in vivo testing of multiple next-generation vaccines defined the prerequisites for induction of a potent immune response in Atlantic salmon. A prototype DNA-launched replicon vaccine has shown potential for further development. The research described in this thesis contributes to the development of next-generation vaccines in the challenging area of fish vaccinology.
Composting trial with BioFoam® products in a full scale commercial composting facility : final report, April 2015
Zee, M. van der - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Wageningen UR Food & Biobased Research report 1561) - ISBN 9789462575141 - 31
biobased economy - biobased materials - biomass - organic wastes - degradation - composts - composting - biotechnology - technology - plastic foam - biobased economy - materialen uit biologische grondstoffen - biomassa - organisch afval - degradatie - compost - compostering - biotechnologie - technologie - schuimplastic
The main objective of the trial was to be able to judge whether BioFoam® material degrades at sufficient rate to be composted together with regular source separated municipal solid biowaste in a full scale industrial composting facility.
Bacterial battery chargers
Versluis, K. ; Heijne, A. ter - \ 2015
stedelijk afvalwater - afvalwaterbehandeling - elektriciteit - elektronen - bacteriën - bio-energie - biobased economy - biotechnologie - waterzuivering - municipal wastewater - waste water treatment - electricity - electrons - bacteria - bioenergy - biotechnology - water treatment
Annemiek ter Heijne investigates a new method to produce electricity from waste water. She uses bacteria as battery chargers.
Editorial : Seeds and places: The geographies of transgenic crops in the global south
Dowd-Uribe, B. ; Glover, D. ; Schnurr, M.A. - \ 2014
Geoforum 53 (2014). - ISSN 0016-7185 - p. 145 - 148.
genetically-modified crops - food security - bio-hegemony - bt cotton - biotechnology - science - poor - argentina - dynamics - impacts
Prof. Justus Wesseler over overheidsingrijpen bij nieuwe biotechnologische ontwikkelingen
Wesseler, J.H.H. - \ 2014
genetische modificatie - transgene planten - transgene organismen - biotechnologie - schade - rijst - india - economische aspecten - genetic engineering - transgenic plants - transgenic organisms - biotechnology - damage - rice - economic aspects
Overheidsregels rond biotechnologie en genetisch gemodificeerde gewassen leiden vaak tot substantieel hoge investeringskosten. Die hebben weer een lager niveau van productontwikkeling tot gevolg en een concentratie in de industrie, een herschikking van onderzoeksprioriteiten en een verschuiving van onderzoek en ontwikkeling naar landen met minder stringente regelgeving. Die trend leidde zelfs tot schade aan duurzame ontwikkeling uit oogpunt van milieu en volksgezondheid.
|Genenfluisteren : kunst en kunde
Tramper, J. ; Mossink, L. - \ 2014
Wageningen : Johanes Tramper - ISBN 9789082203103 - 139
biotechnologie - voedselbiotechnologie - wetenschap - wetenschapsfilosofie - biotechnology - food biotechnology - science - philosophy of science
Attitudes towards genetically modified animals in food production
Frewer, L.J. ; Coles, D. ; Houdebine, L.M. ; Kleter, G.A. - \ 2014
British Food Journal 116 (2014)8. - ISSN 0007-070X - p. 1291 - 1313.
bovine growth-hormone - consumer acceptance - united-states - gm food - risk perceptions - perceived risk - south-korea - biotechnology - willingness - trust
Purpose – Food products developed using genetically modified (GM) animals may soon be introduced in Europe and beyond. Their successful commercialisation depends on consumer acceptance, and so it is timely to review the existing literature in this respect. The paper aims to discuss these issues. Design/methodology/approach – A systematic review identified 42 English language peer reviewed papers assessing public opinion of GM animals associated with food production. Thematic analysis was applied to the results to identify and explain consumer attitudes. Findings – Publication peaked in 2004, and declined thereafter. European consumers were less accepting of GM animal technology than the US and Asian consumers, although the latter reported more ethical concern. Risk and benefit perceptions, ethical concerns (e.g. related to animal welfare) may explain negative consumer attitudes towards animals in food production. Research limitations/implications – There is a lack of data on consumer attitudes to GM animals applied to food production, in particular in relation to consumers in emerging economies and developing countries. This is problematic as applications of GM animal products are about to enter the market. Practical implications – There is a need to track changes in public opinion as GM food production animals are further developed. The introduction and commercialisation of applications with specific characteristics may further shape consumer attitudes. Social implications – Methods need to be developed to involve consumers and other stakeholders in shaping future applications of agri-food applications of GM animals. Originality/value – The review collates existing quantitative and qualitative knowledge regarding the drivers of consumer attitudes towards GM animals used in food production using systematic review methodology.
On the traces of Hephaestus : skills, technology and social participation
Nicolosi, G. - \ 2014
Wageningen University. Promotor(en): Han Wiskerke; Guido Ruivenkamp. - Wageningen University : Wageningen - ISBN 9789462570672 - 173
technologie - technische vooruitgang - samenleving - sociologie - filosofie - participatie - vaardigheden - biotechnologie - technology - technical progress - society - sociology - philosophy - participation - skills - biotechnology
In the general understanding, and also in scientific practice, technology and society are viewed as two distinct entities. Related to this view is the assumption that technology and human experience are quite different and unconnected and also the idea that modernity has uprooted, de-contextualized and disembodied technical rationality. Taking a contrary approach, this study represents a theoretical exploration aimed at showing that in the domain of technological development, there are significant margins for maneuver in which to recuperate and valorize human and social action. As a work of theoretical sociology or social epistemology, this thesis approaches its subject from the theoretical background of the philosophy and sociology of technique. The historical and conventional assumptions of this theoretical background, it is argued, have been and continue to be characterized by a hegemonically defined essentialist paradigm. This paradigm has been fiercely counteracted by two opposed approaches, critical theory and pragmatism. The present work combines these approaches, usually considered mutually incompatible, for the development of a new theoretical gaze or perspective. The aim has been to engage in a theoretical research oriented to a new philosophy of praxis in order to instigate a critical and constructivist approach to technology. The main result expected of this work is the provision of a problematized and multifaceted semantic map leading to a multidimensional conceptual re-integration of skilled experience in human technical action.
Development of late blight resistant potatoes by cisgenic stacking
Jo, K.R. ; Kim, C.J. ; Kim, S.J. ; Kim, T.J. ; Bergervoet-van Deelen, J.E.M. ; Jongsma, M.A. ; Visser, R.G.F. ; Jacobsen, E. ; Vossen, J.H. - \ 2014
BMC Biotechnology 14 (2014). - ISSN 1472-6750
broad-spectrum resistance - cultivar sarpo mira - phytophthora-infestans - solanum-bulbocastanum - r-gene - plants - transformation - genomics - tomato - biotechnology
Background Phytophthora infestans, causing late blight in potato, remains one of the most devastating pathogens in potato production and late blight resistance is a top priority in potato breeding. The introduction of multiple resistance (R) genes with different spectra from crossable species into potato varieties is required. Cisgenesis is a promising approach that introduces native genes from the crops own gene pool using GM technology, thereby retaining favourable characteristics of established varieties. Results We pursued a cisgenesis approach to introduce two broad spectrum potato late blight R genes, Rpi-sto1 and Rpi-vnt1.1 from the crossable species Solanum stoloniferum and Solanum venturii, respectively, into three different potato varieties. First, single R gene-containing transgenic plants were produced for all varieties to be used as references for the resistance levels and spectra to be expected in the respective genetic backgrounds. Next, a construct containing both cisgenic late blight R genes (Rpi-vnt1.1 and Rpi-sto1), but lacking the bacterial kanamycin resistance selection marker (NPTII) was transformed to the three selected potato varieties using Agrobacterium-mediated transformation. Gene transfer events were selected by PCR among regenerated shoots. Through further analyses involving morphological evaluations in the greenhouse, responsiveness to Avr genes and late blight resistance in detached leaf assays, the selection was narrowed down to eight independent events. These cisgenic events were selected because they showed broad spectrum late blight resistance due to the activity of both introduced R genes. The marker-free transformation was compared to kanamycin resistance assisted transformation in terms of T-DNA and vector backbone integration frequency. Also, differences in regeneration time and genotype dependency were evaluated. Conclusions We developed a marker-free transformation pipeline to select potato plants functionally expressing a stack of late blight R genes. Marker-free transformation is less genotype dependent and less prone to vector backbone integration as compared to marker-assisted transformation. Thereby, this study provides an important tool for the successful deployment of R genes in agriculture and contributes to the production of potentially durable late blight resistant potatoes.
Multivariate PAT solutions for biopharmaceutical cultivation: current progress and limitations
Mercier, S.M. ; Diepenbroek, B. ; Wijffels, R.H. ; Streefland, M. - \ 2014
Trends in Biotechnology 32 (2014)6. - ISSN 0167-7799 - p. 329 - 336.
process analytical technology - principal component analysis - monitoring batch processes - cell-culture - biotechnology - spectroscopy - quality - chromatography - fermentation - chemometrics
Increasingly elaborate and voluminous datasets are generated by the (bio)pharmaceutical industry and are a major challenge for application of PAT and QbD principles. Multivariate data analysis (MVDA) is required to delineate relevant process information from large multi-factorial and multi-collinear datasets. Here the key role of MVDA for industrial (bio)process data is discussed, with a focus on progress and limitations of MVDA as a PAT solution for biopharmaceutical cultivation processes. MVDA based models were proven useful and should be routinely implemented for bioprocesses. It is concluded that although the highest level of PAT with process control within its design space in real-time during manufacturing is not reached yet, MVDA will be central to reach this ultimate objective for cell cultivations.
|Lotz B (2013) “Genetische modificatie geen wondermiddel”. Interview in serie Zomercollege.
Versprille, H. ; Lotz, L.A.P. - \ 2013
Boerderij 98 (2013)47. - ISSN 0006-5617 - p. 12 - 14.
genetische modificatie - cisgenese - maatschappelijk draagvlak - biotechnologie - aardappelen - gewasbescherming - plantenveredeling - genetic engineering - cisgenesis - public support - biotechnology - potatoes - plant protection - plant breeding
Bert Lotz houdt zich bij Plant Research International (onderdeel Wageningen UR) onder meer bezig met biologische bestrijding en genetische modificatie. Hij mist respect voor de wetenschap in het debat over 'gentech'. "We staan pas aan de vooravond van talloze toepassingen." Een interview.
|Control of Pig Reproduction IX
Rodriguez-Martinez, H. ; Soede, N.M. ; Flowers, W.L. - \ 2013
Leicestershire, United Kingdom : Context Products Ltd (Society of Reproduction and Fertility volume 68) - ISBN 9781899043484 - 345
varkens - geslachtelijke voortplanting - gameten - embryo's - kunstmatige inseminatie - embryotransplantatie - zwangerschap - partus - pasgeborenen - biggen - overleving - biotechnologie - metabolomica - eiwitexpressieanalyse - kunstmatige selectie - pigs - sexual reproduction - gametes - embryos - artificial insemination - embryo transfer - pregnancy - parturition - neonates - piglets - survival - biotechnology - metabolomics - proteomics - artificial selection