Regulation of Ace2-dependent genes requires components of the PBF complex in schizosaccharomyces pombe

The division cycle of unicellular yeasts is completed with the activation of a cell separation program that results in the dissolution of the septum assembled during cytokinesis between the 2 daughter cells, allowing them to become independent entities. Expression of the eng1+ and agn1+ genes, encoding the hydrolytic enzymes responsible for septum degradation, is activated at the end of each cell cycle by the transcription factor Ace2. Periodic ace2+ expression is regulated by the transcriptional complex PBF (PCB Binding Factor), composed of the forkhead-like proteins Sep1 and Fkh2 and the MADS box-like protein Mbx1. In this report, we show that Ace2-dependent genes contain several combinations of motifs for Ace2 and PBF binding in their promoters. Thus, Ace2, Fkh2 and Sep1 were found to bind in vivo to the eng1+ promoter. Ace2 binding was coincident with maximum level of eng1+ expression, whereas Fkh2 binding was maximal when mRNA levels were low, supporting the notion that they play opposing roles. In addition, we found that the expression of eng1+ and agn1+ was differentially affected by mutations in PBF components. Interestingly, agn1+ was a major target of Mbx1, since its ectopic expression resulted in the suppression of Mbx1 deletion phenotypes. Our results reveal a complex regulation system through which the transcription factors Ace2, Fkh2, Sep1 and Mbx1 in combination control the expression of the genes involved in separation at the end of the cell division cycle

Reformulation of queries using similarity thesauri

Este artículo trata sobre la recuparación de la información en thesaurus similares.One of the major problems in information retrieval is the formulation of queries on thepart of the user. This entails specifying a set of words or terms that express their informationalneed. However, it is well-known that two people can assign different terms to refer tothe same concepts. The techniques that attempt to reduce this problem as much as possiblegenerally start from a first search, and then study how the initial query can be modified toobtain better results. In general, the construction of the new query involves expanding theterms of the initial query and recalculating the importance of each term in the expandedquery. Depending on the technique used to formulate the new query several strategies aredistinguished. These strategies are based on the idea that if two terms are similar (withrespect to any criterion), the documents in which both terms appear frequently will also berelated. The technique we used in this study is known as query expansion using similaritythesauri

Prototyping a spinning adsorber submerged filter for continuous removal of wastewater contaminants

Adsorption process is widely used for the removal of wastewater contaminants. Classic adsorption units are fixed beds and membrane filtration systems. In this work a novel configuration of a bench scale spinning adsorber submerged filter is proposed. Different prototypes of cylindric, truncated cone or prismatic spinning adsorbers were studied using activated carbon of different particle sizes GAC (1.5 mm, Granulated), μGAC (0.475 mm, microGranulated), and cPAC (0.237 mm, coarse Powder) as adsorbent, and azorubine as model adsorbate. High maximum azorubine adsorptions per unit mass of adsorbent of 214, 225 and 275 mg/g for GAC, μGAC and cPAC, respectively, were obtained using the Langmuir isotherm adsorption model. Batch adsorption followed pseudo-second order kinetics, and adsorbate uptake rate increased with decreasing adsorbent particle size. Best adsorption unit was a tank equipped with a spinning rectangular prism adsorber prototype all made of stainless-steel woven wire filter of 180 mesh size. Running at 600 rpm and filled with a high cPAC concentration (25 g/L), adsorber can remove azorubine at similar rates that the use of free moving cPAC. Adsorber unit can run in continuous mode and works even better as a novel spinning submerged filter where filtered flow exits from a central pipe axis. This integrated adsorption-submerged filtration operation mode offer the possibility of adding a high initial dose or a continuous dosing of adsorbent in the tank, increasing the adsorbent concentration of the unit. This system can also offer novel opportunities for wastewater contaminants removal using different adsorbent materials located separately.We want to thank Hector Flores Aparicio (Industrial Design and Scientific Calculation Service, UPCT) for 3D printing of studied prototypes and useful suggestions. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Septins localize to microtubules during nutritional limitation in Saccharomyces cerevisiae

<p>Abstract</p> <p>Background</p> <p>In <it>Saccharomyces cerevisiae</it>, nutrient limitation stimulates diploid cells to undergo DNA replication and meiosis, followed by the formation of four haploid spores. Septins are a family of proteins that assemble a ring structure at the mother-daughter neck during vegetative growth, where they control cytokinesis. In sporulating cells, the septin ring disassembles and septins relocalize to the prospore membrane.</p> <p>Results</p> <p>Here, we demonstrate that nutrient limitation triggers a change in the localization of at least two vegetative septins (Cdc10 and Cdc11) from the bud neck to the microtubules. The association of Cdc10 and Cdc11 with microtubules persists into meiosis, and they are found associated with the meiotic spindle until the end of meiosis II. In addition, the meiosis-specific septin Spr28 displays similar behavior, suggesting that this is a common feature of septins. Septin association to microtubules is a consequence of the nutrient limitation signal, since it is also observed when haploid cells are incubated in sporulation medium and when haploid or diploid cells are grown in medium containing non-fermentable carbon sources. Moreover, during meiosis II, when the nascent prospore membrane is formed, septins moved from the microtubules to this membrane. Proper organization of the septins on the membrane requires the sporulation-specific septins Spr3 and Spr28.</p> <p>Conclusion</p> <p>Nutrient limitation in <it>S. cerevisiae </it>triggers the sporulation process, but it also induces the disassembly of the septin bud neck ring and relocalization of the septin subunits to the nucleus. Septins remain associated with microtubules during the meiotic divisions and later, during spore morphogenesis, they are detected associated to the nascent prospore membranes surrounding each nuclear lobe. Septin association to microtubules also occurs during growth in non-fermentable carbon sources.</p

β(1,3)-Glucanosyl-Transferase Activity Is Essential for Cell Wall Integrity and Viability of Schizosaccharomyces pombe

13 páginas, 7 figuras, 2 tablas.[Background]: The formation of the cell wall in Schizosaccharomyces pombe requires the coordinated activity of enzymes involved in the biosynthesis and modification of b-glucans. The b(1,3)-glucan synthase complex synthesizes linear b(1,3)- glucans, which remain unorganized until they are cross-linked to other b(1,3)-glucans and other cell wall components. Transferases of the GH72 family play important roles in cell wall assembly and its rearrangement in Saccharomyces cerevisiae and Aspergillus fumigatus. Four genes encoding b(1,3)-glucanosyl-transferases -gas1+, gas2+, gas4+ and gas5+- are present in S. pombe, although their function has not been analyzed. [Methodology/Principal Findings]: Here, we report the characterization of the catalytic activity of gas1p, gas2p and gas5p together with studies directed to understand their function during vegetative growth. From the functional point of view, gas1p is essential for cell integrity and viability during vegetative growth, since gas1D mutants can only grow in osmotically supported media, while gas2p and gas5p play a minor role in cell wall construction. From the biochemical point of view, all of them display b(1,3)-glucanosyl-transferase activity, although they differ in their specificity for substrate length, cleavage point and product size. In light of all the above, together with the differences in expression profiles during the life cycle, the S. pombe GH72 proteins may accomplish complementary, non-overlapping functions in fission yeast. [Conclusions/Significance]: We conclude that b(1,3)-glucanosyl-transferase activity is essential for viability in fission yeast, being required to maintain cell integrity during vegetative growth.This research was supported by grants from the Comision Interministerial de Ciencia y Tecnologia (BFU2004-00778) and Junta de Castilla y Leon (GR231) to C.R.V-A and from the European Community (LSHB-CT-2004-511952) to C.R.V-A. and J.P.L. M.M-R. held a fellowship from the Ministerio de Educacion y Ciencia.Peer reviewe

Morphological variation and different branch modularity across contrasting flow conditions in dominant Pocillopora reef-building corals

© 2015, Springer-Verlag Berlin Heidelberg. Pocillopora corals, the dominant reef-builders in the Eastern Tropical Pacific, exhibit a high level of phenotypic plasticity, making the interpretation of morphological variation and the identification of species challenging. To test the hypothesis that different coral morphospecies represent phenotypes that develop in different flow conditions, we compared branch characters in three Pocillopora morphospecies (P.damicornis, P. verrucosa, and P. meandrina) from two communities in the Gulf of California exposed to contrasting flow conditions. Morphological variation and branch modularity (i.e., the tendency of different sets of branch traits to vary in a coordinated way) were assessed in colonies classified as Pocillopora type 1 according to two mitochondrial regions. Our results can be summarized as follows. (1) Pocillopora type 1 morphospecies corresponded to a pattern of morphological variation in the Gulf of California. Overall, P.damicornis had the thinnest branches and its colonies the highest branch density, followed by P.verrucosa, and then by P.meandrina, which had the thickest branches and its colonies the lowest branch density. (2) The differentiation among morphospecies was promoted by different levels of modularity of traits. P.verrucosa had the highest coordination of traits, followed by P.damicornis, and P.meandrina. (3) The variation and modularity of branch traits were related to water flow condition. Morphology under the high-flow condition was more similar among morphospecies than under the low-flow condition and seemed to be related to mechanisms for coping with these conditions. Our results provide the first evidence that in scleractinian corals different levels of modularity can be promoted by different environmental conditions

Un motor de búsqueda para la investigación experimental en Recuperación de la Informaciónmediante SQL.

La Recuperación de Información experimenta en los últimos tiempos un auge notable, debido a la disponibilidad cada vez mayor de documentos en formato electrónico. Uno de los campos de investigación es la experimentación con diversos algoritmos referentes a cualquiera de las fases que pueden darse en el proceso de recuperación. Dicha investigación requiere, entre otras cosas, de una serie de herramientas o intrumentos que permitan la realización de experimentos. Entre esos instrumentos están los motores de recuperación; este trabajo expone cómo diseñar un motor de recuperación utilizando un Sistema de Base de Datos Relacional, y sentencias SQL.Research on Information Retrieval shows a remarkable growth nowadays, due to the availability of documents in electronic format. One of the research fields is the experimentation with algorithms referring to any of the tasks that can occur in the retrieval process. This research requires, among other things, of tools that allow the accomplishment of experiments. Betweenthose tools they are the search engines; this report shows how to design a search engine using a Relational Data Base Management System and SQL sentences

Dinámica de septinas y regulación de la separación celular durante el crecimiento hifal de Candida albicans ¿una diana de antifúngicos?

Resumen del trabajo presentado al "IV Congreso GEBMP: Simposio Hongos Patógenos" celebrado en Badajoz el 6 de julio del 2012.Peer Reviewe

El sistema de recuperación Karpanta: estudio de usuarios a través del archivo de registro

A model for the analysis of interaction between users and information retrieval systems in the context of digital libraries is proposed, based on the study of the transaction logs of the retrieval system “Karpanta”Se presenta el análisis de los archivos de registro del sistema de recuperación Karpanta como un modelo del análisis de la interacción entre usuarios y sistemas en el contexto de las bibliotecas digitales. (A

El uso de metadatos en las webs universitarias españolas

The objective is to show the real use of metadata and which ones are used by all the Spanish universities. We will use the robot SACARINO (that was presented in Ibersid 2005) for the collection of all the data and then we will process the information in order to obtain the results, that will be shown in a graphical way so that they are easy to understand.El objetivo es mostrar la utilización real de metadatos y los que se usan de todas las universidades españolas. Emplearemos el robot SACARINO (presentado en Ibersid 2005) para la recogida de todos los datos y a partir de ahí procesaremos la información para poder obtener los resultados. Se mostrarán los resultados de forma gráfica, lo que facilitará una rápida comprensión de los mismos