Linking biogeochemical variability and microbial community structure in forest soils: Abies pinsapo-fir forests as a study case

Tradicionalmente, los estudios biogeoquímicos consideraban el suelo como una "caja negra", conectada con el resto del ecosistema mediante flujos de entrada y de salida de nutrientes, en la que éstos experimentan transformaciones mediadas en gran parte por microorganismos desconocidos. El desarrollo de nuevas técnicas moleculares ha incrementado el conocimiento sobre las comunidades microbianas del suelo. Estudios recientes han puesto de manifiesto correspondencias entre la variabilidad de la disponibilidad de nutrientes y la estructura de la comunidad microbiana en suelos forestales. A este respecto, hemos empleado bosques de Abies pinsapo como modelo ya que muestran una gran variabilidad biogeoquímica asociada a diferencias litológicas y sucesionales, mientras que la estacionalidad mediterránea provoca una alta variabilidad intra anual en la disponibilidad de nutrientes. Además, existen pinsapares sujetos a limitación o a saturación de nitrógeno. Mediante análisis del polimorfismo de longitud de fragmentos de restricción terminal (T-RFLP), hemos puesto de manifiesto que los patrones de variabilidad biogeoquímica descritos en los pinsapares se corresponden con cambios en la composición y estructura de sus comunidades bacterianas.Traditionally, soil has been considered as a "black box", connected to the rest of the ecosystem by input and output fluxes, where nutrients are transformed mainly through processes controlled by unknown microorganisms. The development of new molecular techniques has increased our knowledge about microbiological soil communities. Recent studies reveal that change in nutrient availability in forest soils is associated with shifts in the soil community structure. We have used Abies pinsapo fir forests as a model case to this regard, since they show a marked among-sites biogeochemical variability due to changes in lithology and successional status, while Mediterranean seasonality determines high intra-year variability in nutrients availability. Moreover, A. pinsapo forests that are either N-limited or N-saturated do exist. Using terminal restriction fragments length polymorphism (T-RFLP) analysis we have demonstrated that these patterns of biogeochemical variability are associated with shifts in the structure of the soil bacterial communities

Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean grasslands dominated by Stipa tenacissima to simultaneously evaluate the effects of shrub encroachment on the structure and composition of multiple biotic community components, and on various indicators of ecosystem function. Shrub encroachment enhanced vascular plant richness, biomass of fungi, actinomycetes and other bacteria, and was linked with greater soil fertility and N mineralization rates. While shrub encroachment may be a widespread phenomenon in drylands, an interpretation that this is an expression of desertification is not universal. Our results suggest that shrub establishment may be an important step in the reversal of desertification processes in the Mediterranean region.F.T.M. and M.A.B. were supported by ‘Ramón y Cajal’ and ‘Juan de la Cierva’ contracts from the Spanish MICINN (co-funded by the European Social Fund). F.T.M. was also supported by the British Ecological Society (ECPG 231/607 and Studentship 231/1975) and MICINN (CGL2008-00986-E/BOS project). This research was funded by grants from the Fundación BBVA (BIOCON06/105), Comunidad de Madrid (REMEDINAL, S-0505/AMB/0335), and Universidad Rey Juan Carlos (URJC-RNT-063-2).Peer reviewe

Cross-disease Meta-analysis of Genome-wide Association Studies for Systemic Sclerosis and Rheumatoid Arthritis Reveals IRF4 as a New Common Susceptibility Locus

Objectives: Systemic sclerosis (SSc) and rheumatoid arthritis (RA) are autoimmune diseases that share clinical and immunological characteristics. To date, several shared SSc- RA loci have been identified independently. In this study, we aimed to systematically search for new common SSc-RA loci through an inter-disease meta-GWAS strategy. Methods: We performed a meta-analysis combining GWAS datasets of SSc and RA using a strategy that allowed identification of loci with both same-direction and opposingdirection allelic effects. The top single-nucleotide polymorphisms (SNPs) were followed-up in independent SSc and RA case-control cohorts. This allowed us to increase the sample size to a total of 8,830 SSc patients, 16,870 RA patients and 43,393 controls. Results: The cross-disease meta-analysis of the GWAS datasets identified several loci with nominal association signals (P-value < 5 x 10-6), which also showed evidence of association in the disease-specific GWAS scan. These loci included several genomic regions not previously reported as shared loci, besides risk factors associated with both diseases in previous studies. The follow-up of the putatively new SSc-RA loci identified IRF4 as a shared risk factor for these two diseases (Pcombined = 3.29 x 10-12). In addition, the analysis of the biological relevance of the known SSc-RA shared loci pointed to the type I interferon and the interleukin 12 signaling pathways as the main common etiopathogenic factors. Conclusions: Our study has identified a novel shared locus, IRF4, for SSc and RA and highlighted the usefulness of cross-disease GWAS meta-analysis in the identification of common risk loci

Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals

Programa poblacional de cribado de sordera neonatal en Galicia: organización y resultados: 2002-2007

Introducción. La detección precoz del déficit auditivo en el periodo neonatal permite instaurarun programa de rehabilitación temprana para mejorar la capacidad de comunicación de los niños afec-tados por déficit de audición. Con este objetivo se han iniciado en los sistemas sanitarios de muchospaíses programas poblacionales de cribado de hipoacusia a los recién nacidos. Material y métodos. La población objetivo la constituyen todos los recién nacidos en Galicia. El programa fue implantado de forma progresiva desde mayo del 2002 hasta junio del 2008 en todoslos hospitales de la red pública gallega y en algunos hospitales privados. La prueba de cribado con-siste en la realización de potenciales evocados auditivos automatizados. Se realiza preferentementeantes del alta hospitalaria. Las unidades de cribado están integradas por personal del propio centro. El personal de enfermería es el encargado de realizar la prueba de cribado de forma habitual en sujornada laboral. Si antes de que el niño abandone el centro se obtiene un resultado positivo de laprueba, tanto unilateral como bilateral, el niño es derivado para confirmación diagnóstica. Resultados. Tanto la cobertura como la participación aumentaron desde un 46 y un 69,11% en2002 a un 89 y un 99,78% respectivamente en 2007, con un total de 80.166 niños cribados en los 6años de funcionamiento. La tasa de derivación global fue de 0,84% y el número de casos diagnostica-dos de hipoacusia fue de 64, lo que sitúa la tasa de detección global en 0,80 por mil niños cribados. Conclusiones. La aceptación de la prueba ha sido muy buena, hecho que se refleja en la altaparticipación que alcanzó, el 99% en 2003, manteniéndose en años sucesivos. La tasa de derivaciónobservada —0,84%— es relativamente baja, por lo que está siendo motivo de estudio. La tasa dedetección ha ido aumentando con la cobertura del programa, acercándose a la incidencia esti-mada de hipoacusia neonat

Metabolic Rewiring and Altered Glial Differentiation in an iPSC-Derived Astrocyte Model Derived from a Nonketotic Hyperglycinemia Patient

The pathophysiology of nonketotic hyperglycinemia (NKH), a rare neuro-metabolic disorder associated with severe brain malformations and life-threatening neurological manifestations, remains incompletely understood. Therefore, a valid human neural model is essential. We aimed to investigate the impact of GLDC gene variants, which cause NKH, on cellular fitness during the differentiation process of human induced pluripotent stem cells (iPSCs) into iPSC-derived astrocytes and to identify sustainable mechanisms capable of overcoming GLDC deficiency. We developed the GLDC27-FiPS4F-1 line and performed metabolomic, mRNA abundance, and protein analyses. This study showed that although GLDC27-FiPS4F-1 maintained the parental genetic profile, it underwent a metabolic switch to an altered serine–glycine–one-carbon metabolism with a coordinated cell growth and cell cycle proliferation response. We then differentiated the iPSCs into neural progenitor cells (NPCs) and astrocyte-lineage cells. Our analysis showed that GLDC-deficient NPCs had shifted towards a more heterogeneous astrocyte lineage with increased expression of the radial glial markers GFAP and GLAST and the neuronal markers MAP2 and NeuN. In addition, we detected changes in other genes related to serine and glycine metabolism and transport, all consistent with the need to maintain glycine at physiological levels. These findings improve our understanding of the pathology of nonketotic hyperglycinemia and offer new perspectives for therapeutic options

Data from: Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean grasslands dominated by Stipa tenacissima to simultaneously evaluate the effects of shrub encroachment on the structure and composition of multiple biotic community components, and on various indicators of ecosystem function. Shrub encroachment enhanced vascular plant richness, biomass of fungi, actinomycetes and other bacteria, and was linked with greater soil fertility and N mineralization rates. While shrub encroachment may be a widespread phenomenon in drylands, an interpretation that this is an expression of desertification is not universal. Our results suggest that shrub establishment may be an important step in the reversal of desertification processes in the Mediterranean region

Data from: Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean grasslands dominated by Stipa tenacissima to simultaneously evaluate the effects of shrub encroachment on the structure and composition of multiple biotic community components, and on various indicators of ecosystem function. Shrub encroachment enhanced vascular plant richness, biomass of fungi, actinomycetes and other bacteria, and was linked with greater soil fertility and N mineralization rates. While shrub encroachment may be a widespread phenomenon in drylands, an interpretation that this is an expression of desertification is not universal. Our results suggest that shrub establishment may be an important step in the reversal of desertification processes in the Mediterranean region

Environmental and soil data from encroached/unencroached Stipa tenacissima steppes from Spain

Environmental (coordinates, elevation, slope, aspect, mean annual rainfall and temperature) and soil (pH, organic carbon, total nitrogen, total phosphorus, soil respiration, potassium and nitrogen mineralization) variables at the microsite and site scales for Stipa tenacissima grasslands with and without sprouting shrubs in a gradient from central to southern Spain