241 research outputs found
Targeting of prolamins by RNAi in bread wheat: Effectiveness of seven silencing-fragment combinations for obtaining lines devoid of coeliac disease epitopes from highly immunogenic gliadins
Gluten proteins are responsible for the viscoelastic properties of wheat flour but also for triggering pathologies in susceptible individuals, of which coeliac disease (CD) and noncoeliac gluten sensitivity may affect up to 8% of the population. The only effective treatment for affected persons is a strict gluten-free diet. Here, we report the effectiveness of seven plasmid combinations, encompassing RNAi fragments from a-, c-, x-gliadins, and LMW glutenin subunits, for silencing the expression of different prolamin fractions. Silencing patterns of transgenic lines were analysed by gel electrophoresis, RP-HPLC and mass spectrometry (LC-MS/ MS), whereas gluten immunogenicity was assayed by an anti-gliadin 33-mer monoclonal antibody (moAb). Plasmid combinations 1 and 2 downregulated only c- and a-gliadins, respectively. Four plasmid combinations were highly effective in the silencing of x-gliadins and c-gliadins, and three of these also silenced a-gliadins. HMW glutenins were upregulated in all but one plasmid combination, while LMW glutenins were downregulated in three plasmid combinations. Total protein and starch contents were unaffected regardless of the plasmid combination used. Six plasmid combinations provided strong reduction in the gluten content as measured by moAb and for two combinations, this reduction was higher than 90% in comparison with the wild type. CD epitope analysis in peptides identified in LC-MS/MS showed that lines from three plasmid combinations were totally devoid of CD epitopes from the highly immunogenic a- and x-gliadins. Our findings raise the prospect of breeding wheat species with low levels of harmful gluten, and of achieving the important goal of developing nontoxic wheat cultivars
Low-gluten, nontransgenic wheat engineered with CRISPR/Cas9
Coeliac disease is an autoimmune disorder triggered in genetically predisposed individuals by the
ingestion of gluten proteins from wheat, barley and rye. The a-gliadin gene family of wheat
contains four highly stimulatory peptides, of which the 33-mer is the main immunodominant
peptide in patients with coeliac. We designed two sgRNAs to target a conserved region adjacent
to the coding sequence for the 33-mer in the a-gliadin genes. Twenty-one mutant lines were
generated, all showing strong reduction in a-gliadins. Up to 35 different genes were mutated in
one of the lines of the 45 different genes identified in the wild type, while immunoreactivity was
reduced by 85%. Transgene-free lines were identified, and no off-target mutations have been
detected in any of the potential targets. The low-gluten, transgene-free wheat lines described
here could be used to produce low-gluten foodstuff and serve as source material to introgress
this trait into elite wheat varieties.Ministerio de Economía y Competitividad AGL2013-48946-C3-1-R ; AGL2016-80566-
Molecular and Immunological Characterization of Gluten Proteins Isolated from Oat Cultivars That Differ in Toxicity for Celiac Disease
A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease (CD). Traditionally, treatment with a GFD has excluded wheat, barley and rye, while the presence of oats is a subject of debate. The most-recent research indicates that some cultivars of oats can be a safe part of a GFD. In order to elucidate the toxicity of the prolamins from oat varieties with low, medium, and high CD toxicity, the avenin genes of these varieties were cloned and sequenced, and their expression quantified throughout the grain development. At the protein level, we have accomplished an exhaustive characterization and quantification of avenins by RP-HPLC and an analysis of immunogenicity of peptides present in prolamins of different oat cultivars. Avenin sequences were classified into three different groups, which have homology with S-rich prolamins of Triticeae. Avenin proteins presented a lower proline content than that of wheat gliadin; this may contribute to the low toxicity shown by oat avenins. The expression of avenin genes throughout the development stages has shown a pattern similar to that of prolamins of wheat and barley. RP-HPLC chromatograms showed protein peaks in the alcohol-soluble and reduced-soluble fractions. Therefore, oat grains had both monomeric and polymeric avenins, termed in this paper gliadin- and glutenin-like avenins. We found a direct correlation between the immunogenicity of the different oat varieties and the presence of the specific peptides with a higher/lower potential immunotoxicity. The specific peptides from the oat variety with the highest toxicity have shown a higher potential immunotoxicity. These results suggest that there is wide range of variation of potential immunotoxicity of oat cultivars that could be due to differences in the degree of immunogenicity in their sequences
Sediment characteristics influence the fertilisation success of the corals Acropora tenuis and Acropora millepora
Elevated suspended sediment concentrations (SSCs) often impact coral fertilisation success, but sediment composition can influence effect thresholds, which is problematic for accurately predicting risk. Here, we derived concentration–response thresholds and cause-effect pathways for SSCs comprising a range of realistic mineral and organic compositions on coral fertilisation success. Effect concentration thresholds (EC10: 10% fertilisation inhibition) varied markedly, with fertilisation highly sensitive to inshore organic-clay rich sediments and bentonite clay at 40 mg L−1). The effect thresholds for relevant sediment types were combined with in situ turbidity data from locations near dredging operations to assess the risks posed by dredging to coral fertilisation at these locations
Two centuries of hydroclimatic variability reconstructed from tree-ring records over the Amazonian Andes of Peru
Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high‐quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provide a complete record since 1979 and offer a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scales. We developed the first annually resolved precipitation reconstruction for the tropical Andes in Peru, based on tree‐ring chronologies of Cedrela and Juglans species. The annual (November–October) reconstruction extends the short instrumental records back to 1817, explaining 68% of the total variance of precipitation over the 1979–2007 calibration period. The reconstruction reveals the well‐documented influence of El Niño‐ Southern Oscillation (ENSO) on Amazon Rainfall at interannual scales (~19% of total variance) and significant multidecadal variability with alternating periods of about 40 years (~13% of rainfall variability) related to the Atlantic Multidecadal Oscillation (AMO). Both oscillatory modes can explain dry and humid periods observed within the reconstruction and are likely associated with the negative trends of rainfall in the short instrumental records and the increased drought recurrence in recent decades. Our results show that montane tropical tree rings can be used to reconstruct precipitation with exceptionally high fidelity, characterize the interannual to multidecadal variability, and identify remote forcings in the hydroclimate over the Andean Amazon Basin of Peru
Restoration as a meaningful aid to ecological recovery of coral reefs
Restoration supports the recovery of ecological attributes such as cover, complexity, and diversity to slow the areal decline of natural ecosystems. Restoration activity is intensifying worldwide to combat persistent stressors that are driving global declines to the extent and resilience of coral reefs. However, restoration is disputed as a meaningful aid to reef ecological recovery, often as an expensive distraction to addressing the root causes of reef loss. We contend this dispute partly stems from inferences drawn from small-scale experimental restoration outcomes amplified by misconceptions around cost-based reasoning. Alongside aggressive emissions reductions, we advocate urgent investment in coral reef ecosystem restoration as part of the management toolbox to combat the destruction of reefs as we know them within decades
Evaluating the role of moonlight-darkness dynamics as proximate spawning cues in an <em>Acropora</em> coral
\ua9 The Author(s) 2025. For sessile broadcast spawning marine invertebrates, such as corals, successful sexual reproduction depends on conspecifics spawning synchronously. The precise monthly, lunar, and diel timing and the extent of synchrony, i.e., proportion of population reproducing at the same time, are likely to play a key role in coral population recovery, persistence, and adaptation. Despite its importance, the mechanisms by which different environmental factors trigger corals to spawn on specific dates within the lunar cycle remain poorly understood. Periods of darkness post-sunset around full moon of the spawning month have been shown to induce spawning in merulinid corals, whereas for Acropora, moonlight is considered the main determinant driver of night of spawning. Here, we conducted two manipulative field experiments around full moon in Palau using the common table coral Acropora aff. hyacinthus to disentangle the role of moonlight and darkness post-sunset as proximate cues. Coral fragments were assigned to three treatments providing different post-sunset darkness conditions, versus control and procedural control fragments exposed to natural conditions. In contrast to previous studies on Acropora, we found that Acropora aff. hyacinthus can spawn synchronously in the absence of moonlight during the nights leading to spawning. Corals exposed to darkness post-sunset for at least two to three consecutive nights advanced their spawning compared to controls. This finding indicates that periods of darkness post-sunset can act as an inducer for spawning in Acropora as well as in merulinid corals, suggesting that this mechanism may be more widespread than previously thought
The Relationship between Depressive Symptoms, Quality of Life and miRNAs 8 Years after Bariatric Surgery
Altres ajuts: Universidad de Málaga, UMA20-FEDERJA-144; Junta de Andalucia, PI-0194-2017, C-0028-2018, RC-005-2020, DOC_00288 and DOC_01095Background: There are conflicting results on whether weight loss after bariatric surgery (BS) might be associated with quality of life (QoL)/depressive symptomatology. We aim to determine whether BS outcomes are associated with QoL/depressive symptomatology in studied patients at the 8-year follow-up after BS, as well as their relationship with different serum proteins and miRNAs. Methods: A total of 53 patients with class III obesity who underwent BS, and then classified into "good responders" and "non-responders" depending on the percentage of excess weight lost (%EWL) 8 years after BS (%EWL ≥ 50% and %EWL < 50%, respectively), were included. Basal serum miRNAs and different proteins were analysed, and patients completed tests to evaluate QoL/depressive symptomatology at 8 years after BS. Results: The good responders group showed higher scores on SF-36 scales of physical functioning, role functioning-physical, role functioning-emotional, body pain and global general health compared with the non-responders. The expression of hsa-miR-101-3p, hsa-miR-15a-5p, hsa-miR-29c-3p, hsa-miR-144-3p and hsa-miR-19b-3p were lower in non-responders. Hsa-miR-19b-3p was the variable associated with the response to BS in a logistic regression model. Conclusions: The mental health of patients after BS is limited by the success of the intervention. In addition, the expression of basal serum miRNAs related to depression/anxiety could predict the success of BS
Selective breeding enhances coral heat tolerance to marine heatwaves
\ua9 The Author(s) 2024.Marine heatwaves are becoming more frequent, widespread and severe, causing mass coral bleaching and mortality. Natural adaptation may be insufficient to keep pace with climate warming, leading to calls for selective breeding interventions to enhance the ability of corals to survive such heatwaves, i.e., their heat tolerance. However, the heritability of this trait–a prerequisite for such approaches–remains unknown. We show that selecting parent colonies for high rather than low heat tolerance increased the tolerance of adult offspring (3–4-year-olds). This result held for the response to both 1-week +3.5 \ub0C and 1-month +2.5 \ub0C simulated marine heatwaves. In each case, narrow-sense heritability (h2) estimates are between 0.2 and 0.3, demonstrating a substantial genetic basis of heat tolerance. The phenotypic variability identified in this population could theoretically be leveraged to enhance heat tolerance by up to 1 \ub0C-week within one generation. Concerningly, selective breeding for short-stress tolerance did not improve the ability of offspring to survive the long heat stress exposure. With no genetic correlation detected, these traits may be subject to independent genetic controls. Our finding on the heritability of coral heat tolerance indicates that selective breeding could be a viable tool to improve population resilience. Yet, the moderate levels of enhancement we found suggest that the effectiveness of such interventions also demands urgent climate action
Scientific exploitation of PAZ products in coastal surveillance and monitoring tasks
Revista oficial de la Asociación Española de Teledetección[EN] PAZ mission appears due to the need of a Spanish SAR satellite able to provide radar image products for security and defense, civil and scientific users. INTA is responsible for the technical direction of the Ground Segment, as well as the development of the Calibration and Validation Centre and the scientific exploitation. The ‘Demonstrator of Maritime SAR Applications’ is proposed as an answer to detection tasks in maritime synthetic aperture radar imagery, which are not completely solved yet. DeMSAR has been developed in the framework of a contract between the Spanish National Institute for Aerospace Technology (INTA) and the University of Alcalá. It is intended to be used as a demonstrator of the capabilities of the airborne SAR prototypes of INTA as well as for PAZ, the Spanish SAR satellite. With two operation modes, an automatic ship detector and a toolboxes mode, DeMSAR offers the user a high flexibility in SAR data processing tasks such as speckle filtering, coastline detection, land mask estimation and ship detection and characterization.[ES] La misión PAZ surge ante la necesidad de un satélite SAR español que pueda proporcionar productos imagen radar para usuarios de seguridad y defensa, civiles y científicos. INTA es el responsable de la dirección técnica del Segmento Terreno, así como del desarrollo y operación del Centro de Calibración y Validación y de la Explotación Científica. Dentro de este ámbito de explotación, se desarrolla un demostrador de aplicaciones SAR marítimas (DeMSAR) como herramienta robusta capaz de llevar a cabo tareas de detección sobre la superficie marina, empleando las imágenes adquiridas por radares de apertura sintética. Se desarrolla bajo un marco de colaboración entre el INTA y la Universidad de Alcalá con el fin de convertirse en un demostrador de las capacidades de los sistemas aerotransportados de INTA y, en el futuro, para procesar los datos adquiridos por el sensor PAZ. Con capacidad de operar en modo automático de detección de barcos o mediante librerías de procesado SAR, DeMSAR ofrece una gran versatilidad al usuario en tareas de procesado tales como filtrado de ruido speckle, detección de líneas de costa, estimación de máscaras de tierra y detección y caracterización de barcos.Jarabo, M.; González, M.; De La Mata, D.; Martín De Nicolás, J.; Del Rey, N.; Bárcena, J.; Peláez, V. (2014). Explotación científica de productos PAZ en tareas de vigilancia y monitorización costera. Revista de Teledetección. (41):97-109. doi:10.4995/raet.2014.2287.SWORD9710941Comaniciu, D., & Meer, P. (2002). Mean shift: a robust approach toward feature space analysis. IEEE Transactions on Pattern Analysis and Machine Intelligence, 24(5), 603-619. doi:10.1109/34.1000236Duda, R. O. & Hart, P. E., 1973. Pattern classification and scene analysis. Wiley.Mallat, S., 2008. A wavelet tour of signal processing. 3rd Edition. Academic Press
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