16 research outputs found
Protoplast Transformation of Phytophthora spp.
No full textAt the core of assays to understand the role(s) of specific genes is the ability to stably transfer genes into Phytophthora through transformation. A key method for achieving this has been based on polyethylene glycol (PEG)/CaCl2 transformation of protoplasts, but efficiency has often been low. Improving transformation efficiency is necessary for many applications, such as gene knockouts. Here we describe improvements through successive rounds of “mock” transformation, leading to improved efficiency in Phytophthora infestans and other species.</p
RNA Silencing Strategies in Phytophthora:Experimental Guidelines and Insights
No full textRNA silencing is a core cellular process that acts to defend the genome against potentially damaging genetic elements such as viruses and transposons. It has been extensively characterized in many eukaryotes and exploited as a tool for determining gene function through removing the activity of specific genes. It has also been used in Phytophthora species to reveal genes involved in different lifecycle stages. In this chapter, we provide guidelines and outline considerations for carrying out RNA silencing experiments in Phytophthora.</p
Proteolytic processing of both RXLR and EER motifs in oomycete effectors
No full textArg-any amino acid-Leu-Arg (RXLR) effectors are central oomycete virulence factors that suppress plant immunity. Relatively little is known about how they are processed post-translationally before delivery into host cells. A range of molecular, cell and biochemical processes were used to investigate proteolytic processing of RXLR and Glu-Glu-Arg (EER) motifs in Phytophthora infestans effectors. Proteolytic cleavage at the RXLR motif occurred before secretion in all effectors tested, suggesting it is a general rule. Cleavage occurred between the leucine and the second arginine. There was no cleavage of a naturally occurring second RXLR motif in a structured region of Pi21388/AvrBlb1, or one introduced at a similar position in effector Pi04314, in keeping with the motif being positionally constrained, potentially to disordered regions closely following the signal peptide. Remarkably, independent proteolytic cleavage of the EER motif, often found immediately after the RXLR, was also observed, occurring immediately after the arginine. Full-length effectors expressed in host plant Nicotiana benthamiana revealed that, although secreted, they were poorly processed, suggesting that RXLR and EER cleavage does not occur in all eukaryotic cells. We conclude that, whether possessing both RXLR and EER, or either motif alone, these effectors are likely generally proteolytically processed before secretion.</p
Building bridges to primary education in Mauritius? emergent literacy experiences in a foreign language context : a case study of preschool children
No full textIncludes abstract.Includes bibliographical references (leaves 354-445).In the context where English, as a foreign language, is the main language of literacy and the written medium of instruction throughout the Mauritian education system, this thesis explores (1) preschoolers' early literacy experiences, (2) the outcomes of these experiences, and (3) the extent to which these experiences prepare them to use English in Standard 1. The theoretical and empirical research on emergent literacy, second/foreign language learning and teaching, second/foreign language literacy instruction and new literacies was reviewed in order to find some "anchor points" (Hamilton, 2006) in the literature. These "anchor points" guided this exploratory study on emergent/early literacy experiences in a multilingual context. After a pilot study, I embarked on a yearlong case study ofa group of preschool children and their teachers using an ethnographic approach
Identification of MARVELous Protein Markers for Phytophthora infestans Extracellular Vesicles
No full textExtracellular vesicles (EVs) are released from cells by unconventional secretion, but little is known about the biogenesis routes, composition or cargoes of EVs from fungal or oomycete plant pathogens. We investigated the proteome of EV-associated proteins secreted by the oomycete Phytophthora infestans, cause of potato late blight disease. We found that vesicle-associated proteins, transmembrane proteins and RxLR effectors, which are delivered into host cells to suppress immunity, were enriched in the EV proteome. By contrast, the EV-independent secreted proteome was enriched in cell wall modifying enzymes and apoplastic effectors which act outside plant cells. Two proteins, each containing two tetraspanning MARVEL domains, PiMDP1 and PiMDP2, were associated with P. infestans EVs. PiMDP1 and PiMDP2 were co-buoyant with RxLR effectors in sucrose density fractions containing EVs and co-localised frequently with each other and with RxLRs at vesicles within pathogen hyphae grown in vitro and during infection. Interestingly, PiMDP2, which is up-regulated during the early biotrophic phase of infection, accumulates at the haustorial interface, a major site of effector secretion during infection. We argue that PiMDP1 and PiMDP2 are molecular markers that will facilitate studies of the biogenesis and secretion of infection-associated P. infestans EVs.</p
Testing a global standard for quantifying species recovery and assessing conservation impact
No full textRecognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a “Green List of Species” (now the IUCN Green Status of Species). A draft Green Status framework for assessing species’ progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species’ viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species’ recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard.
Inclusive author list: Molly K. Grace • H. Resit Akçakaya • Elizabeth L. Bennett • Thomas M. Brooks • Anna Heath • Simon Hedges • Craig Hilton-Taylor • Michael Hoffmann • Axel Hochkirch • Richard Jenkins • David A. Keith • Barney Long • David P. Mallon • Erik Meijaard • E.J. Milner-Gulland • Jon Paul Rodriguez • P.J. Stephenson • Simon N. Stuart • Richard P. Young • Pablo Acebes • Joanna Alfaro-Shigueto • Silvia Alvarez-Clare • Raphali Rodlis Andriantsimanarilafy • Marina Arbetman • Claudio Azat • Gianluigi Bacchetta • Ruchi Badola • Luís M.D. Barcelos • Joao Pedro Barreiros • Sayanti Basak • Danielle J. Berger • Sabuj Bhattacharyya • Gilad Bino • Paulo A.V. Borges • Raoul K. Boughton • H. Jane Brockmann • Hannah L. Buckley • Ian J. Burfield • James Burton • Teresa Camacho-Badani • Luis Santiago Cano-Alonso • Ruth H. Carmichael • Christina Carrero • John P. Carroll • Giorgos Catsadorakis • David G. Chapple • Guillaume Chapron • Gawsia Wahidunnessa Chowdhury • Louw Claassens • Donatella Cogoni • Rochelle Constantine • Christie Anne Craig • Andrew A. Cunningham • Nishma Dahal • Jennifer C. Daltry • Goura Chandra Das • Niladri Dasgupta • Alexandra Davey • Katharine Davies • Pedro Develey • Vanitha Elangovan • David Fairclough • Mirko Di Febbraro • Giuseppe Fenu • Fernando Moreira Fernandes • Eduardo Pinheiro Fernandez • Brittany Finucci • Rita Földesi • Catherine M. Foley • Matthew Ford • Michael R.J. Forstner • Néstor García • Ricardo Garcia-Sandoval • Penny C. Gardner • Roberto Garibay-Orijel • Marites Gatan-Balbas • Irene Gauto • Mirza Ghazanfar Ullah Ghazi • Stephanie S. Godfrey • Matthew Gollock • Benito A. González • Tandora D. Grant • Thomas Gray • Andrew J. Gregory • Roy H.A. van Grunsven • Marieka Gryzenhout • Noelle C. Guernsey • Garima Gupta • Christina Hagen • Christian A. Hagen • Madison B. Hall • Eric Hallerman • Kelly Hare • Tom Hart • Ruston Hartdegen • Yvette Harvey-Brown • Richard Hatfield • Tahneal Hawke • Claudia Hermes • Rod Hitchmough • Pablo Melo Hoffmann • Charlie Howarth • Michael A. Hudson • Syed Ainul Hussain • Charlie Huveneers • Hélène Jacques • Dennis Jorgensen • Suyash Katdare • Lydia K.D. Katsis • Rahul Kaul • Boaz Kaunda-Arara • Lucy Keith-Diagne • Daniel T. Kraus • Thales Moreira de Lima • Ken Lindeman • Jean Linsky • Edward Louis Jr. • Anna Loy • Eimear Nic Lughadha • Jeffrey C. Mangel • Paul E. Marinari • Gabriel M. Martin • Gustavo Martinelli • Philip J.K. McGowan • Alistair McInnes • Eduardo Teles Barbosa Mendes • Michael J. Millard • Claire Mirande • Daniel Money • Joanne M. Monks • Carolina Laura Morales • Nazia Naoreen Mumu • Raquel Negrao • Anh Ha Nguyen • Md. Nazmul Hasan Niloy • Grant Leslie Norbury • Cale Nordmeyer • Darren Norris • Mark O’Brien • Gabriela Akemi Oda • Simone Orsenigo • Mark Evan Outerbridge • Stesha Pasachnik • Juan Carlos Pérez-Jiménez • Charlotte Pike • Fred Pilkington • Glenn Plumb • Rita de Cassia Quitete Portela • Ana Prohaska • Manuel G. Quintana • Eddie Fanantenana Rakotondrasoa • Dustin H. Ranglack • Hassan Rankou • Ajay Prakash Rawat • James Thomas Reardon • Marcelo Lopes Rheingantz • Stephen C. Richter • Malin C. Rivers • Luke Rollie Rogers • Patrícia da Rosa • Paul Rose • Emily Royer • Catherine Ryan • Yvonne J. Sadovy de Mitcheson • Lily Salmon • Carlos Henrique Salvador • Michael J. Samways • Tatiana Sanjuan • Amanda Souza • dos Santos • Hiroshi Sasaki • Emmanuel Schutz • Heather Ann Scott • Robert Michael Scott • Fabrizio Serena • Surya P. Sharma • John A. Shuey • Carlos Julio Polo Silva • John P. Simaika • David R. Smith • Julia L.Y. Spaet • Shanjida Sultana • Bibhab Kumar Talukdar • Vikash Tatayah • Philip Thomas • Angela Tringali • Hoang Trinh-Dinh • Chongpi Tuboi • Aftab Alam Usmani • Aída M. Vasco-Palacios • Jean-Christophe Vié • Jo Virens • Alan Walker • Bryan Wallace • Lauren J. Waller • Hongfeng Wang • Oliver R. Wearn • Merlijn van Weerd • Simon Weigmann • Daniel Willcox • John Woinarski • Jean W.H. Yong • Stuart Young
AVR2 targets BSL family members, which act as susceptibility factors to suppress host immunity
No full textTo be successful plant pathogens, microbes use "effector proteins" to manipulate host functions to their benefit. Identifying host targets of effector proteins and characterizing their role in the infection process allow us to better understand plant-pathogen interactions and the plant immune system. Yeast two-hybrid analysis and coimmunoprecipitation were used to demonstrate that the Phytophthora infestans effector AVIRULENCE 2 (PiAVR2) interacts with all three BRI1-SUPPRESSOR1-like (BSL) family members from potato (Solanum tuberosum). Transient expression of BSL1, BSL2, and BSL3 enhanced P. infestans leaf infection. BSL1 and BSL3 suppressed INFESTIN 1 elicitin-triggered cell death, showing that they negatively regulate immunity. Virus-induced gene silencing studies revealed that BSL2 and BSL3 are required for BSL1 stability and show that basal levels of immunity are increased in BSL-silenced plants. Immune suppression by BSL family members is dependent on the brassinosteroid-responsive host transcription factor CIB1/HBI1-like 1. The P. infestans effector PiAVR2 targets all three BSL family members in the crop plant S. tuberosum These phosphatases, known for their role in growth-promoting brassinosteroid signaling, all support P. infestans virulence and thus can be regarded as susceptibility factors in late blight infection.</p
Insight in Psychosis: Relationship With Neurocognition, Social Cognition and Clinical Symptoms Depends on Phase of Illness
No full textReduced insight has been reported in a majority of patients with a psychotic disorder. Most studies have focused on associations with neurocognition, neglecting relations with social cognition. Two hundred seventy patients with nonaffective psychosis participated in this study, which was part of the GROUP (Genetic Risk and OUtcome of Psychosis)-project. Linear regression analyses were performed to investigate the predictive value of composite measures of neurocognition, social cognition, and clinical symptoms. The moderating effect of phase of illness was also investigated. Insight was measured with a composite measure, based on the insight item on the Positive And Negative Syndrome Scale (PANSS) and the Birchwood Insight Scale (BIS). Insight on the BIS and the PANSS correlated significantly (r =. 406). All independent variables correlated with the insight composite measure. The additional effect of social cognition and clinical symptoms were both significant. Phase of illness was a moderating variable: In patients with recent-onset psychosis (ROP), none of the independent variables explained variance. In patients with multiple episode or chronic psychosis, both social cognition and clinical symptoms had additional effects and explained insight, along with neurocognition, together explaining 20% of the variance. These findings indicate that multiple factors are associated with insight in psychosis. Specifically, associations of insight with social cognitive and clinical symptom measures were observed, over and above a contribution of neurocognition. This supports theories that imply a role for deficient emotion recognition and mentalizing in reduced insight. Further studies need to investigate insight in ROP into more detail. © 2010 The Author
Search for new phenomena in final states with large jet multiplicities and missing transverse momentum with ATLAS using TeV proton--proton collisions
No full textSee paper for full list of authors - 20 pages plus author list (37 pages total), 12 figures, 4 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2015-07International audienceResults are reported of a search for new phenomena, such as supersymmetric particle production, that could be observed in high-energy proton--proton collisions. Events with large numbers of jets, together with missing transverse momentum from unobserved particles, are selected. The data analysed were recorded by the ATLAS experiment during 2015 using the 13 TeV centre-of-mass proton--proton collisions at the Large Hadron Collider, and correspond to an integrated luminosity of 3.2 fb. The search selected events with various jet multiplicities from to jets, and with various -jet multiplicity requirements to enhance sensitivity. No excess above Standard Model expectations is observed. The results are interpreted within two supersymmetry models, where gluino masses up to 1400 GeV are excluded at 95% confidence level, significantly extending previous limits
Identification of high transverse momentum top quarks in pp collisions at s√ = 8 TeV with the ATLAS detector
No full text59 pages plus author list + cover page (77 pages total), 24 figures, 5 tables, submitted to JHEP, see paper for full list of authors.International audienceThis paper presents studies of the performance of several jet-substructure techniques, which are used to identify hadronically decaying top quarks with high transverse momentum contained in large-radius jets. The efficiency of identifying top quarks is measured using a sample of top-quark pairs and the rate of wrongly identifying jets from other quarks or gluons as top quarks is measured using multijet events collected with the ATLAS experiment in 20.3 fb−1 of 8 TeV proton-proton collisions at the Large Hadron Collider. Predictions from Monte Carlo simulations are found to provide an accurate description of the performance. The techniques are compared in terms of signal efficiency and background rejection using simulations, covering a larger range in jet transverse momenta than accessible in the dataset. Additionally, a novel technique is developed that is optimized to reconstruct top quarks in events with many jets
