RESUMEN
Citizen and stakeholder engagement is frequently portrayed as vital for socially accountable science policy but there is a growing understanding of how institutional dynamics shape engagement exercises in ways that prevent them from realising their full potential. Limited attention has been devoted to developing the means to expose institutional features, allow policy-makers to reflect on how they will shape engagement and respond appropriately. Here, therefore, we develop and test a methodological framework to facilitate pre-engagement institutional reflexivity with one of the United Kingdom's eminent science organisations as it grappled with a new, high-profile and politicised technology, genome editing. We show how this approach allowed policy-makers to reflect on their institutional position and enrich decision-making at a time when they faced pressure to legitimate decisions with engagement. Further descriptions of such pre-engagement institutional reflexivity are needed to better bridge theory and practice in the social studies of science.
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Edición GénicaRESUMEN
Legumes improve their mineral nutrition through nitrogen-fixing root nodule symbioses with soil rhizobia. Rhizobial infection of legumes is regulated by a number of transcription factors, including ERF Required for Nodulation1 (ERN1). Medicago truncatula plants defective in ERN1 are unable to nodulate, but still exhibit early symbiotic responses including rhizobial infection. ERN1 has a close homolog, ERN2, which shows partially overlapping expression patterns. Here we show that ern2 mutants exhibit a later nodulation phenotype than ern1, being able to form nodules but with signs of premature senescence. Molecular characterization of the ern2-1 mutation reveals a key role for a conserved threonine for both DNA binding and transcriptional activity. In contrast to either single mutant, the double ern1-1 ern2-1 line is completely unable to initiate infection or nodule development. The strong ern1-1 ern2-1 phenotype demonstrates functional redundancy between these two transcriptional regulators and reveals the essential role of ERN1/ERN2 to coordinately induce rhizobial infection and nodule organogenesis. While ERN1/ERN2 act in concert in the root epidermis, only ERN1 can efficiently allow the development of mature nodules in the cortex, probably through an independent pathway. Together, these findings reveal the key roles that ERN1/ERN2 play at the very earliest stages of root nodule development.
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Medicago truncatula/metabolismo , Medicago truncatula/microbiología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Raíces de Plantas/microbiología , Rhizobium/fisiología , Simbiosis , Factores de Transcripción/metabolismo , Alelos , Secuencia de Aminoácidos , Secuencia de Bases , Regulación de la Expresión Génica de las Plantas , Medicago truncatula/genética , Medicago truncatula/ultraestructura , Mutación/genética , Micorrizas/fisiología , Fijación del Nitrógeno , Organogénesis/genética , Epidermis de la Planta/genética , Epidermis de la Planta/microbiología , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raíces de Plantas/genética , Raíces de Plantas/ultraestructura , Regiones Promotoras Genéticas/genética , Unión Proteica , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Nódulos de las Raíces de las Plantas/ultraestructura , Transducción de Señal/genética , Simbiosis/genética , Factores de Transcripción/química , Transcripción GenéticaRESUMEN
The formation of a nitrogen-fixing nodule requires the coordinated development of rhizobial colonization and nodule organogenesis. Based on its mutant phenotype, lumpy infections (lin), LIN functions at an early stage of the rhizobial symbiotic process, required for both infection thread growth in root hair cells and the further development of nodule primordia. We show that spontaneous nodulation activated by the calcium- and calmodulin-dependent protein kinase is independent of LIN; thus, LIN is not necessary for nodule organogenesis. From this, we infer that LIN predominantly functions during rhizobial colonization and that the abortion of this process in lin mutants leads to a suppression of nodule development. Here, we identify the LIN gene in Medicago truncatula and Lotus japonicus, showing that it codes for a predicted E3 ubiquitin ligase containing a highly conserved U-box and WD40 repeat domains. Ubiquitin-mediated protein degradation is a universal mechanism to regulate many biological processes by eliminating rate-limiting enzymes and key components such as transcription factors. We propose that LIN is a regulator of the component(s) of the nodulation factor signal transduction pathway and that its function is required for correct temporal and spatial activity of the target protein(s).
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Lotus/genética , Medicago truncatula/genética , Proteínas de Plantas/metabolismo , Nodulación de la Raíz de la Planta/genética , Ubiquitina-Proteína Ligasas/genética , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Mapeo Cromosómico , Clonación Molecular , ADN de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Prueba de Complementación Genética , Lotus/enzimología , Medicago truncatula/enzimología , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/enzimología , Plantas Modificadas Genéticamente/genética , Regiones Promotoras Genéticas , Análisis de Secuencia de ADN , Transducción de Señal , Simbiosis/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
This article is based on a literature review comparing insertion techniques of the laryngeal mask airway (LMA). I will be looking at the manufacturer's recommended technique and identifying alternative methods, adapted for ease of use, patient comfort or individual circumstances. Risks associated with LMA use will be identified and examples given of research carried out to limit these risks.
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Máscaras Laríngeas , HumanosRESUMEN
Rhizobial bacteria activate the formation of nodules on the appropriate host legume plant, and this requires the bacterial signaling molecule Nod factor. Perception of Nod factor in the plant leads to the activation of a number of rhizobial-induced genes. Putative transcriptional regulators in the GRAS family are known to function in Nod factor signaling, but these proteins have not been shown to be capable of direct DNA binding. Here, we identify an ERF transcription factor, ERF Required for Nodulation (ERN), which contains a highly conserved AP2 DNA binding domain, that is necessary for nodulation. Mutations in this gene block the initiation and development of rhizobial invasion structures, termed infection threads, and thus block nodule invasion by the bacteria. We show that ERN is necessary for Nod factor-induced gene expression and for spontaneous nodulation activated by the calcium- and calmodulin-dependent protein kinase, DMI3, which is a component of the Nod factor signaling pathway. We propose that ERN is a component of the Nod factor signal transduction pathway and functions downstream of DMI3 to activate nodulation gene expression.