On the way to specificity ‐ Microbiome reflects sponge genetic cluster primarily in highly structured populations

Most animals, including sponges (Porifera), have species-specific microbiomes. Which genetic or environmental factors play major roles structuring the microbial community at the intraspecific level in sponges is, however, largely unknown. In this study, we tested whether geographic location or genetic structure of conspecific sponges influences their microbial assembly. For that, we used three sponge species with different rates of gene flow, and collected samples along their entire distribution range (two from the Mediterranean and one from the Southern Ocean) yielding a total of 393 samples. These three sponge species have been previously analysed by microsatellites or single nucleotide polymorphisms, and here we investigate their microbiomes by amplicon sequencing of the microbial 16S rRNA gene. The sponge Petrosia ficiformis, with highly isolated populations (low gene flow), showed a stronger influence of the host genetic distance on the microbial composition than the spatial distance. Host-specificity was therefore detected at the genotypic level, with individuals belonging to the same host genetic cluster harbouring more similar microbiomes than distant ones. On the contrary, the microbiome of Ircinia fasciculata and Dendrilla antarctica - both with weak population structure (high gene flow) - seemed influenced by location rather than by host genetic distance. Our results suggest that in sponge species with high population structure, the host genetic cluster influence the microbial community more than the geographic location

Redefinició dels serveis bibliotecaris de suport a la investigació des de la perspectiva de l'espai europeu de recerca

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Algal symbionts of the freshwater sponge Ephydatia muelleri

The freshwater sponge, Ephydatia muelleri, is an emerging model system for studying animal:microbe symbioses. Intracellular green microalgae are one of the more common symbionts that live in a facultative mutualism with E. muelleri. While these symbioses have long been known, the identity of the algal symbionts in E. muelleri cells has not been studied in detail. Here, we isolate and characterize endosymbiotic algae from E. muelleri collected from different geographic locations. We find that the algae can be transmitted through asexually produced gemmules and importantly that they can form symbioses with different, differentiated sponge cell types in the adult sponge. Our findings indicate that at least two algal lineages form endosymbioses with E. muelleri. One of the lineages includes species commonly found in samples from two locations in Canada and one in the United States (clade 1: closely related to Auxenochlorella pyrenoidosa). The other clade includes algae found in sponges from one site in Maine, USA, and Lewiniosphaera symbiontica, which is a strain isolated in 1956 from the freshwater sponge Spongilla. We compared microbiomes found in cultures of microalgae as well as the original sponge hosts, and found that very similar bacterial microbiomes associate with both clades (91 orders of Bacteria are shared among the samples we compared). The microbiomes found in the cultures resemble, with a high degree of overlap, the microbiome associated with the sponge host

Universidad, género, docencia e igualdad

La Red de investigación en docencia universitaria “Universidad, docencia, genero e igualdad” persigue avanzar en la calidad e innovación de las enseñanzas universitarias a partir de la inclusión de la perspectiva de género. Se busca dar cumplimiento a las directrices generales de los nuevos planes de estudio respecto del principio de igualdad de oportunidades entre hombres y mujeres en la formación universitaria (Real Decreto 1393/2007. BOE nº 260, 30 de octubre de 2007). En la cuarta edición de la Red, y dada su composición multidisciplinar, se desarrollaron tres líneas de investigación: 1) mantenimiento del “Portal web con recursos docentes con perspectiva de género”, proyecto financiado por el Instituto de la Mujer (PACUI, 2012) e iniciado en el curso 2012-2013; 2) desarrollo (primera versión) de “iLengUA”, una herramienta informática para un discurso inclusivo e igualitario; y 3) diseño de la Guía para una orientación universitaria inclusiva

Descubriendo la Diversidad y Estructura de las poblaciones de Bacteroidetes en Ambientes Marinos

Memoria de tesis doctoral presentada por Cristina Díez Vives para optar al grado de Doctora en Oceanografía por la Universidad de las Palmas de Gran Canaria (UB), realizada bajo la dirección de la Dra. Silvia González Acinas y del Dr. Josep M. Gasol Piqué del Institut de Ciències del Mar (ICM-CSIC).-- 242 pagesOne of the main questions in microbial ecology is to understand what are the processes that structure and govern the species composition of communities. Answering to this question implies the need to detect bacterial species in environmental samples or at least to define ecologically meaningful “units of differentiation”. The dynamics and distribution of different broad taxonomic groups that constitute the bacterioplankton (at the phylum or class level) has been widely studied. The different large groups are known to follow different spatial distributions and seasonal cycles, but important variations also occur at lower levels (i.e. species or ecologically distinct populations). In this thesis we aimed to study some of these aspects for an important group of marine bacteria: the phylum Bacteroidetes. First at all, we evaluated the existing molecular tools in an updated phylogenetical and methodological context. Strengths and weaknesses of different probes used in different techniques were thoroughly studied and discussed, and alternatives were designed for some specific purposes related with the study of this group in marine environmental samples. Standing on these tools, we studied the phylum at different levels of resolution resulting from assorted molecular approaches. We related entire phylum abundances with environmental parameters as they vary spatially and temporally in the oceanic realm. We identified the most abundant phylotypes forming the Bacteroidetes assemblages and their ecological variability. Both the relative abundance and the changes in the phylotypes constituting the community followed clear spatial and seasonal patterns, which were thoroughly described. To increase the resolution of our study, we built extensive clone libraries including the 16S-ITS-23S ribosomal operon. The phylogenetic study of these sequences from different environmental samples showed that closely related phylotypes were organized in monophyletic clades of habitat specific sequences. This confirmed that similar bacteria (in terms of the 16S rRNA) seem to present different physiologies, which would drive their distribution and adaption to specific ecological niches. The study of the distributions of these clades would help to understand the ecology of this group. Finally, we integrated the above information to design several clade-specific qPCR primer sets targeting putative Bacteroidetes ecotypes. These primers were thoroughly tested as the best possible compromise between specificity and performance for the intended purpose, and they were extensively evaluated in silico. An optimization of the qPCR technique workflow and a demonstration of its usefulness was carried out using the NS2b group. These primers offer a toolbox for hierarchical quantitative studies characterizing Bacteroidetes populations in different environments. Such studies should help to explore and corroborate links of certain groups with specific habitats and environmental variablesEsta tesis se ha desarollado con el apoyo de una beca predoctoral del CSIC (JAE Intro). El estudio experimental se ha realizado en el Instituto de Ciencias del Mar (ICM-CSIC) y se ha financiado parcialmente por el Ministerio Español de Ciencia e Innovación mediante los proyectos MICRODIVERSITY (CGL2008-00762/BOS) y MicroOcean PANGENOMICS (CGL2011-26848/BOS) conseguidos por SGAPeer reviewe

Redefinició dels serveis de suport a la investigació des de la perspectiva de l'espai europeu de recerca

Proposal about the services that the universitaries libraries could offer to his users in order to collaborate with their institutions in the activities framed in the European Research Area (ERA)

Evaluation of Marine Bacteroidetes-Specific Primers for Microbial Diversity and Dynamics Studies

9 pages, 2 figures, 2 tablesAssumptions on the matching specificity of group-specific bacterial primers may bias the interpretation of environmental microbial studies. As available sequence data continue growing, the performance of primers and probes needs to be reevaluated. Here, we present an evaluation of several commonly used and one newly designed Bacteroidetes-specific primer (CF418). First, we revised the in silico primer coverage and specificity with the current SILVA and RDP databases. We found minor differences with previous studies, which could be explained by the chosen databases, taxonomies, and matching criteria. We selected eight commonly used Bacteroidetes primers and tested them with a collection of assorted marine bacterial isolates. We also used the denaturing gradient gel electrophoresis (DGGE) approach in environmental samples to evaluate their ability to yield clear and diverse band patterns corresponding to Bacteroidetes phylotypes. Among the primers tested, CF968R did not provide satisfactory results in DGGE, although it exhibited the highest in silico coverage for Flavobacteria. Primers CFB560 and CFB555 presented undesirable features, such as requiring nested protocols or presence of degeneracies. Finally, the new primer CF418 and primer CF319a were used to explore the Bacteroidetes dynamics throughout a 1-year cycle in Mediterranean coastal waters (Blanes Bay Microbial Observatory). Both primers provided clear and diverse banding patterns, but the low specificity of CF319a was evidenced by 83.3 % of the bands sequenced corresponding to nontarget taxa. The satisfactory DGGE banding patterns and the wide diversity of sequences retrieved from DGGE bands with primer CF418 prove it to be a valuable alternative for the study of Bacteroidetes communities, recovering a wide range of phylotypes within the groupWe thank Carlos Pedrós-Alió for critical reading of the manuscript. CDV was a recipient of a JAE-Predoc fellowship from CSIC, and SGA was supported by a RyC contract from the Spanish Ministry of Science and Innovation and CONES 2010-0036 from the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR). This research was supported by grants: MICRODIVERSITY (CGL2008-00762/BOS) to SGA and STORM (CTM2009-09352/MAR) from the Spanish Ministry of Science and Innovation (MICINN)Peer reviewe

Global patterns in symbiont selection and transmission strategies in sponges

Sponges host dense and diverse communities of microbes (known as the microbiome) beneficial for the host nutrition and defense. Symbionts in turn receive shelter and metabolites from the sponge host, making their relationship beneficial for both partners. Given that sponge-microbes associations are fundamental for the survival of both, especially the sponge, such relationship is maintained through their life and even passed on to the future generations. In many organisms, the microbiome has profound effects on the development of the host, but the influence of the microbiome on the reproductive and developmental pathways of the sponges are less understood. In sponges, microbes are passed on to oocytes, sperm, embryos, and larvae (known as vertical transmission), using a variety of methods that include direct uptake from the mesohyl through phagocytosis by oocytes to indirect transmission to the oocyte by nurse cells. Such microbes can remain in the reproductive elements untouched, for transfer to offspring, or can be digested to make the yolky nutrient reserves of oocytes and larvae. When and how those decisions are made are fundamentally unanswered questions in sponge reproduction. Here we review the diversity of vertical transmission modes existent in the entire phylum Porifera through detailed imaging using electron microscopy, available metabarcoding data from reproductive elements, and macroevolutionary patterns associated to phylogenetic constraints. Additionally, we examine the fidelity of this vertical transmission and possible reasons for the observed variability in some developmental stages. Our current understanding in marine sponges, however, is that the adult microbial community is established by a combination of both vertical and horizontal (acquisition from the surrounding environment in each new generation) transmission processes, although the extent in which each mode shapes the adult microbiome still remains to be determined. We also assessed the fundamental role of filtration, the cellular structures for acquiring external microbes, and the role of the host immune system, that ultimately shapes the stable communities of prokaryotes observed in adult sponges

Spatial and temporal variability among marine Bacteroidetes populations in the NW Mediterranean Sea

11 pages, 5 figures, 2 tables, 1 appendix supplementary data https://doi.org/10.1016/j.syapm.2013.08.006The abundance and structure of Bacteroidetes populations at diverse temporal and spatial scales were investigated in the Northwestern Mediterranean Sea. At a temporal scale, their relative abundance exhibited a marked seasonality, since it was higher in spring and decreased in winter. Similarly, Bacteroidetes community structure encompassed three main groups (winter, spring and summer-fall), which mimicked global bacterioplankton seasonality. At the spatial scale, relative abundances were similar in all surface samples along an inshore-offshore transect, but they decreased with depth. Analysis of the community structure identified four markedly different groups mostly related to different depths. Interestingly, seasonal changes in abundance and community structure were not synchronized. Furthermore, richness was higher when Bacteroidetes were less abundant. The variability of Bacteroidetes contributions to community structure in the temporal and spatial scales was correlated with different environmental factors: day length was the most important factor at the temporal scale, and salinity at the spatial scale. The community composition in terms of phylotypes changed significantly over time and along the depth gradients, but season or depth-specific phylogenetic clusters were not identified. Delineation of coherent Bacteroidetes sub-clusters should help to uncover higher resolution patterns within Bacteroidetes, and explore associations with environmental and biological variables. © 2013 Elsevier GmbHCDV was a recipient of a JAE-predoc fellowship from CSIC. SGA was supported by a Ramon y Cajal contract from the Spanish Ministry of Science and Innovation and by MicroB3 (FP7-OCEAN-2011). This research was supported by the grants MICRODIVERSITY (CGL2008-00762/BOS), PANGENOMICS (CGL2011-26848/BOS), GEMMA (CTM2007-63753-C02-01/MAR), SUMMER (CTM2008-03309/MAR) and STORM (CTM2009-09352/MAR) from the Spanish Ministry of Science and Innovation (MICINN)Peer Reviewe

The proteomic study of SAMP8 brain cultures reveals age-related alterations in neurons and astrocytes

Resumen del trabajo presentado en la Alzheimer's Association International Conference on Alzheirme's Disease, celebrada en Viena (Austria), del 11 al 16 de julio de 200