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The effect of Leishmania infantum soluble antigen (LSA) and recombinant Kinetoplastid Membrane Protein 11 (rKMP11) on the induction of ex vivo specific IFN-γ (n = 69) and antibody responses (n = 108) was determined in dogs. All dogs were tested for serological response to both antigens and divided into Group 1: healthy (Asturias, Spain, n = 26), Group 2: sick (n = 46), Group 3: healthy Ibizan hounds (Mallorca, Spain, n = 22) and Group 4: healthy (Bari, Italy, n = 14). Antibody levels were higher for LSA when compared to rKMP11 (p = 0.001). Ibizan hounds were all seronegative to rKMP11 and 18% were low seropositive to LSA. Sick dogs presented higher antibody response to both antigens compared to the rest of the groups (p < 0.0001). All groups showed higher IFN-γ levels after LSA compared to rKMP11 responses (p < 0.05). The highest response to LSA was found in Ibizan hounds (p < 0.05). IFN-γ to LSA and rKMP11 stimulation was observed in 34% and in 2.8% of the sick dogs, respectively. Here, we demonstrated that anti-rKMP11 antibodies are mainly present in dogs with moderate to severe disease. Furthermore, cellular immune response measured by specific ex vivo IFN-γ production was more intense to LSA than stimulated to rKMP11.

Species’ vulnerability to climate change is often assessed by focusing on potential changes of species’ ranges. This study aimed to develop community-level vulnerability indices which measure bryophyte community vulnerability to climate change, based on the best set of factors summarizing species' niche or geographic properties expected to respond to climate change. We used a dataset on 39 saxicolous bryophytes from the Iberian Peninsula, highly sensitive to climate shifts. Niche metrics were calculated using a recently described hypervolume-based approach. Spatial metrics were derived from habitat suitability model (HSM) projections. We then compared regression models based on niche or spatial metrics to evaluate which ones improve species range shifts forecast. The final vulnerability score for each species, the Species Vulnerability Index (SVI), was calculated by applying a weighted sum of all the relevant parameters. We then generated a spatial representation of vulnerability values for the whole community through HSMs and obtained three Community Vulnerability Indices (CVIs), according to different statistical aggregation measures (average, maximum and standard deviation). SVI assigns maximum vulnerability to species with smaller niche breadth and higher marginality in the community environmental niche space continuum, allowing to rank bryophyte species according to their vulnerability. Given the overall importance of niche-hypervolume metrics in SVI and CVIs, we rename it, respectively, as Niche Hypervolume Species Vulnerability Index (NHSVI) and Niche Hypervolume Community Vulnerability Indices (NHCVIs). Overall, saxicolous bryophyte communities with the greatest average vulnerability to climate change are those at the high mountains of the northern, central and southern regions of the Iberian Peninsula. Results suggest that vulnerability patterns are structured locally not only due to species richness but also to community composition. The three NHCVIs provided complementary insights into the study area's community vulnerability distribution. This study shows that NHSVI can prioritise vulnerable species to climate change, and NHCVIs can depict community-wise vulnerability hotspots, thereby informing policymakers in the definition of bryophyte species conservation measures.

Melanin and melanoma tumors are two fields of increasing interest in biomedical research. Melanins are ubiquitous biopigments with adaptive value and multiple functions, and occur in the malignant melanoma. Although several chemical structures have been proposed for eumelanin, molecular modeling and orbitals indicate that a planar or spiral benzoquinone-porphycene polymer would be the model that better explains the broad-band light and ultrasound absorption, electric conductivity, and graphite-like organization shown by X-ray crystallography and electron microscopy. Lysosomes and melanosomes are selectively labeled by vital probes, and melanin also binds to metal cations, colorants, and drugs, with important consequences in pharmacology, pathology, and melanoma therapy. In addition to traditional and recent oncologic treatments, photodynamic, photothermal, and ultrasound protocols represent novel modalities for melanoma therapy. Since eumelanin is practically the ideal photothermal and ultrasound sensitizer, the vibrational decay from photo-excited electrons after NIR irradiation, or the electrochemical production of ROS and radicals after ultrasound absorption, induce an efficient heating or oxidative response, resulting in the damage and death of tumor cells. This allows repetitive treatments due to the remaining melanin contained in tumoral melanophages. Given that evolution and prognosis of the advanced melanoma is still a concern, new biophysical procedures based on melanin properties can now be developed and applied.

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de Lectura: 24-02-2022, A pesar del creciente interés en la edición de genomas microbianos para investigaciones fundamentales y aplicaciones biotecnológicas, todavía hay una escasez de herramientas genéticas para diseñar eficazmente bacterias Gram negativas no-modelo. En este contexto, el objetivo general de esta Tesis ha sido el aumentar las metodologías para la introducción de diversos tipos de mutaciones en diferentes especies bacterianas y fondos genéticos con múltiples propósitos. Con este fin, hemos adaptado la tecnología targetron basada en el intrón del grupo II de Lactococcus lactis, Ll.LtrB, para ser usada en combinación con CRISPR/Cas9 como forma de contraselección. Los intrones del grupo II son un tipo de retroelementos que pueden insertarse en regiones específicas de moléculas de ADN. Sus dianas pueden modificarse de forma que estos intrones pueden ser alterados para reconocer e insertarse en regiones deseadas del genoma, normalmente, con baja frecuencia. Gracias a la contraselección basada en CRISPR/Cas9, la eficiencia para identificar inserciones de Ll.LtrB en Escherichia coli y Pseudomonas putida se incrementó significativamente. Asimismo, pudimos ilustrar la posibilidad de usar esta combinación para mejorar la eficiencia del transporte de fragmentos insertados dentro de Ll.LtrB hacia el genoma de bacterias Gram negativas. Incluso si el límite de tamaño de los fragmentos a transportar fue moderado, también hemos descrito una aplicación útil del sistema para la integración de secuencias cortas que puedan funcionar como identificadores únicos o códigos de barra genéticos en diferentes organismos biológicos. Ya que una de las principales ventajas de los intrones del grupo II es tener un amplio rango de huéspedes, sostenemos que este uso puede ser de gran importancia en la implementación estándar de códigos de barras genéticos para la identificación de chasis relevantes en biotecnología y la protección de propiedad intelectual. Con esto en mente, hemos conseguido aplicar de forma exitosa esta tecnológica basada en la combinación de Ll.LtrB/CRISPR/Cas9 para marcar la cepa bacteriana P. putida KT2440 y su cepa derivada, P. putida EM383, una Factoría Celular. Por otro lado, hemos caracterizado el funcionamiento de los editores de bases generados por fusiones entre citosina deaminasas y la ARN polimerasa del fago T7 en la cepa P. putida EM42, la versión recA+ de la Factoría Celular. Las citosina deaminasas son enzimas capaces de catalizar la desaminación de citosinas a uracilos, generando así transiciones de citosina a timina o uracilo dependiendo de la molécula diana, ADN o ARN. Hemos demostrado el buen comportamiento de dos editores de bases diferentes en esta cepa y hemos llevado a cabo los experimentos necesarios para reducir los niveles basales de expresión de esta herramienta. Esto es beneficioso para asegurar una baja toxicidad del sistema, así como la estabilidad del genotipo seleccionado después de un proceso de evolución. Finalmente, hemos sentado las bases para el desarrollo de una nueva herramienta genética para la identificación de sitios de interacción en el genoma de proteínas de unión al ADN que puede ser utilizado en ciertos escenarios donde las tecnologías actuales presentan limitaciones. Con este fin, hemos usado una novedosa toxina de origen bacteriano con actividad citosina deaminasa, llamada DddA, la cual es capaz de actuar en ADN de doble cadena, una característica inédita que no había sido previamente observada en otra citosina deaminasa hasta la fecha

In the quest for more effective radiation treatment options that can improve both cell killing and healthy tissue recovery, combined radiation therapies are lately in the spotlight. The molecular response to a combined radiation regime where exposure to an initial low dose (priming dose) of ionizing radiation is administered prior to a subsequent higher radiation dose (challenging dose) after a given latency period have not been thoroughly explored. In this study we report on the differential response to either a combined radiation regime or a single challenging dose both in mouse in vivo and in human ex vivo thymocytes. A differential cell cycle response including an increase in the subG1 fraction on cells exposed to the combined regime was found. Together with this, a differential protein expression profiling in several pathways including cell cycle control (ATM, TP53, p21CDKN1A), damage response (γH2AX) and cell death pathways such as apoptosis (Cleaved Caspase-3, PARP1, PKCδ and H3T45ph) and ferroptosis (xCT/GPX4) was demonstrated. This study also shows the epigenetic regulation following a combined regime that alters the expression of chromatin modifiers such as DNMTs (DNMT1, DNMT2, DNMT3A, DNMT3B, DNMT3L) and glycosylases (MBD4 and TDG). Furthermore, a study of the underlying cellular status six hours after the priming dose alone showed evidence of retained modifications on the molecular and epigenetic pathways suggesting that the priming dose infers a “radiation awareness phenotype” to the thymocytes, a sensitization key to the differential response seen after the second hit with the challenging dose. These data suggest that combined-dose radiation regimes could be more efficient at making cells respond to radiation and it would be interesting to further investigate how can these schemes be of use to potential new radiation therapies.

Non-melanoma skin cancer (NMSC) is the most common malignancy worldwide, with rising incidence in the recent years. It includes basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). Several non-invasive therapies have been developed for its treatment such as topical 5-Fluorouracil (5FU) and photodynamic therapy (PDT), among others. Despite both are appropriated for NMSC treatment, recurrence cases have been reported. To prevent this, in this work we explore the potential of the combination of PDT and 5FU to treat SCC and BCC. First we evaluate the efficacy of PDT in cells resistant to 5FU. For this purpose, we use SCC-13 and CSZ-1 cells, obtained from a human SCC and a murine BCC, respectively. We first induced 5FU resistance in these cell lines by repeated treatments with the drug and then, the efficacy to PDT was evaluated. The results obtained indicated that SCC-5FU resistant cells were sensible to PDT administration, whereas BCC-5FU resistant cells were also resistant to PDT. The observed responses in both cell lines are in concordance to Protoporphyrin IX (PpIX) and reactive oxygen species (ROS) levels produced after the incubation with MAL and subsequent light exposure. The obtained data support the fact that PDT seems to be an appropriate therapeutic option to be administered after 5FU resistance in SCC. However, PDT would not be a choice therapy for resistant BCC cells to 5FU, This research was supported by Spanish grants from Instituto de Salud Carlos III Ministerio de Ciencia e innovacion, ´ and Feder Funds (FIS PI18/00708,PI21/00315 and PI21/00953)

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 11-04-2022, Metabolic pathologies and their complications are one of the main causes of death in western high-income countries. Mitochondria are key controllers of metabolism and the skeletal muscle (Skm) structure. However, whether Skm mitochondrial dysfunction is a cause or consequence of metabolic disorders is still controversial. In order to unveil the role of mitochondria in the onset and progression of these pathologies, in this thesis we have developed and characterized the first mouse model of conditional and Skm-specific inhibition of the mitochondrial H+-ATP synthase by the overexpression of its constitutively active inhibitor, ATPIF1|H49K. 6-month-old mice presenting the inhibition of the mitochondrial oxidative phosphorylation (OXPHOS) show a higher body weight compared to control littermates, due to deep alterations in glucose, lipid and amino acid metabolism in both muscle and white adipose tissue. Upon mitochondrial inhibition, Skm increases lactate production, reduces fatty acid β-oxidation, and relies on branched-chain amino acids catabolism as major source of acetyl-CoA for the de novo lipid synthesis. Moreover, acetyl-CoA accumulates in muscle and feedbacks the mitochondrial dysfunction by increasing the production of reactive oxygen species. As a result, mice with restrained OXPHOS become more prone to develop insulin resistance when fed a high-fat diet. Furthermore, Skm mitochondrial dysfunction alters motor behaviour, an effect that increases with ageing. 18-month-old mice presenting a chronic inhibition of the H+-ATP synthase show deep alterations in Skm organization, developing a myopathy characterized by the presence of tubular aggregates (TA), honeycomb-like arrays of sarcoplasmic-reticulum (SR) tubules that disorganize the sarcomere structure. The long-term OXPHOS inhibition reprograms soleus oxidative fibers to glycolytic ones, and increases mitochondrial fission and mitophagy, presumably to recycle defective mitochondria. TA appeared as the result of SR tubulation aimed at increasing mitochondria/SR contact sites to buffer calcium overloads due to prolonged OXPHOS dysfunction. Hence, enhancing OXPHOS activity appears as a promising strategy for therapeutic intervention in metabolic and muscle disorders. With this aim, we screened 702 drugs and identified edaravone as a new mitochondrial antioxidant and enhancer. Remarkably, in vivo edaravone treatment restores a healthy phenotype both in 6-month and 18-month old mice. Altogether, these results suggest that Skm mitochondrial alterations contribute to the setting of metabolic and muscular disorders, proposing edaravone as a potential treatment for these pathologies, This work has been supported by a predoctoral fellowship from the Spanish Ministerio de Economía y Competitividad (BES-2017-079909). The project was funded by the Spanish Ministerio de Economía y Competitividad (Grants SAF2016-76028- R and PID2019- 104241RB-I00)

BackgroundExtracellular vesicles (EVs), released by most cell types, provide an excellent source of biomarkers in biological fluids. However, in order to perform validation studies and screenings of patient samples, it is still necessary to develop general techniques permitting rapid handling of small amounts of biological samples from large numbers of donors.ResultsHere we describe a method that, using just a few microliters of patient’s plasma, identifies tumour markers exposed on EVs. Studying physico-chemical properties of EVs in solution, we demonstrate that they behave as stable colloidal suspensions and therefore, in immunocapture assays, many of them are unable to interact with a stationary functionalised surface. Using flocculation methods, like those used to destabilize colloids, we demonstrate that cationic polymers increase EV ζ-potential, diameter, and sedimentation coefficient and thus, allow a more efficient capture on antibody-coated surfaces by both ELISA and bead-assisted flow cytometry. These findings led to optimization of a protocol in microtiter plates allowing effective immunocapture of EVs, directly in plasma without previous ultracentrifugation or other EV enrichment. The method, easily adaptable to any laboratory, has been validated using plasma from lung cancer patients in which the epithelial cell marker EpCAM has been detected on EVs.ConclusionsThis optimized high throughput, easy to automate, technology allows screening of large numbers of patients to phenotype tumour markers in circulating EVs, breaking barriers for the validation of proposed EV biomarkers and the discovery of new ones.Graphical Abstract

[Introduction]: From an evolutionary perspective, the ribcage has changed substantiallyin the subfamily Homininae. Among many other features, the amount of mineralizedtissues of the rib cross-section at the midshaft could be informative about potentialbiomechanical changes during Homininae evolution. These changes would be relatedto the different loading stresses that each costal level has to deal with. Nevertheless,this knowledge remains hypothetical and has never been properly addressed, [Materials and Methods]:This issue was assessed by analysing via micro-CT the inter-nal rib anatomy of the complete sets of ribs belonging to tenHomo sapiensand tenPan troglodytesadult individuals. Additionally, five fossil ribs ofAustralopithecusafricanusSts 14 (costal levels 5–9) were also included to evaluate similarities with thetwo tested extant species., [Results]:The mineralized area ofP.troglodytesrib cross-sections was higher than thatofH.sapiens. However, its serial change along the rib sequence (1–12/13) was similarin both species. The mineralized area of the Sts 14 rib cross-sections was closer toH.sapiensthan toP.troglodytesfor costal levels 7–9 (Sts 14w) but not for levels 5 and6, where it was distinct from both comparative samples., [Discussion]:The variation in the amount of mineralized tissues along the rib sequence in H.sapiens and P. troglodytes might indicate a common upper-lower thorax division, This project is funded by the Leakey Foundation (ID: 38360; Covariationof internal and external costal anatomy and its importance forunderstanding the evolution of the human thorax) and is linked to theprojects HAR2016-78036-P, HAR2016-74846-P, HAR2017-82755-P, HAR2017-83004-P and PGC2018-099405-B-100 (Spanish Ministry of Economy). Grant PID2020-115854GB-I00 to Markus Bastir is funded by MCIN/AEI/10.13039/501100011033 (Spanish Ministry of Science andInnovation). The JAE Intro program (JAEINT20_EX_0776), from the Consejo Superior de Investigaciones Científicas (CSIC), funds José M. López-Rey and the “Juan de la Cierva Formacion” program (FJCI-2017-32157), from the Spanish Ministry of Science and Innovation, funds Daniel García-Martínez.

Melanins represent one of the most ancient and important group of natural macromolecular pigments. They have multiple biological roles in almost all organisms across the Phyla, examples being photoprotection, anti-oxidative action, radical scavenger activity, and heavy metal removal. From the biomedical point of view, melanocytes are involved in the origin of melanoma tumors, and the main therapeutic advances for their treatment have been revised in Part 1 of this review. The chemical structure of eumelanin is a biological concern of great importance, and therefore, exploring theoretical molecular models and synthesis mechanisms will be here described, as well as molecular orbital features and supramolecular organization, which are responsible for the key properties that make these biological pigments so important, and so fascinating. Ultimately, this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin, in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied

During meiotic prophase I, homologous chromosomes pair, synapse and recombine in a tightly regulated process that ensures the generation of genetically variable haploid gametes. Although the mechanisms underlying meiotic cell division have been well studied in model species, our understanding of the dynamics of meiotic prophase I in non-traditional model mammals remains in its infancy. Here, we reveal key meiotic features in previously uncharacterised marsupial species (the tammar wallaby and the fat-tailed dunnart), plus the fat-tailed mouse opossum, with a focus on sex chromosome pairing strategies, recombina tion and meiotic telomere homeostasis. We uncovered differences between phylogroups with important functional and evolutionary implications. First, sex chromosomes, which lack a pseudo-autosomal region in marsupials, had species specific pairing and silencing strategies, with implications for sex chromosome evolution. Second, we detected two waves of γH2AX accumulation during prophase I. The first wave was accompanied by low γH2AX lev els on autosomes, which correlated with the low recombination rates that distinguish marsupials from eutherian mammals. In the second wave, γH2AX was restricted to sex chromosomes in all three species, which correlated with transcription from the X in tammar wallaby. This suggests non-canonical functions of γH2AX on meiotic sex chromosomes. Finally, we uncover evidence for telomere elongation in primary spermatocytes of the fattailed dunnart, a unique strategy within mammals. Our results provide new insights into meiotic progression and telomere homeostasis in marsupials, highlighting the importance of capturing the diversity of meiotic strategies within mammals, This work was supported by the Ministry of Economy, Industry and Competitiveness (CGL2017-83802-P to A.R-H. and CGL2014- 53106-P to J.P.), the Spanish Ministry of Science and Innovation (PID2020-112557GB-I00 to A.R H.) and the Agència de Gestio´ d’Ajuts Universitaris i de Recerca, AGAUR (SGR1215 to A.R-H.)

In both sexes, aggression has been described as a critical trait to acquire social status. Still, almost uniquely in men, the link between aggressiveness and the genetic background of testosterone sensitivity measured from the polymorphism in the androgen receptor (AR) gene has been previously investigated. We assessed the relevance of the AR gene to understand aggression and how aggressiveness affects social status in a cross-sectional study of 195 participants, for the first time in both young men and women. We estimated polymorphism sequences from saliva and measured aggression and self-perceived social status. Unfortunately, the results did not support our prediction because we did not find any of the expected relationships. Therefore, the results suggest that the genetic association between aggressive mechanisms and polymorphism of the AR gene is less straightforward than expected, at least in men, and seems to indicate that aggression is not usually used to gain social status in our population.

Keratinocyte carcinomas (KCs) are the most prevalent form of cancer worldwide, and their incidence is rising dramatically, with an increasing trend in recent years [...]

Motility and biofilm formation are two crucial traits in the process of rhizosphere colonization by pseudomonads. The regulation of both traits requires a complex signaling network that is coordinated by the AmrZ-FleQ hub. In this review, we describe the role of this hub in the adaption to the rhizosphere. The study of the direct regulon of AmrZ and the phenotypic analyses of an amrZ mutant in Pseudomonas ogarae F113 has shown that this protein plays a crucial role in the regulation of several cellular functions, including motility, biofilm formation, iron homeostasis, and bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, controlling the synthesis of extracellular matrix components. On the other hand, FleQ is the master regulator of flagellar synthesis in P. ogarae F113 and other pseudomonads, but its implication in the regulation of multiple traits related with environmental adaption has been shown. Genomic scale studies (ChIP-Seq and RNA-Seq) have shown that in P. ogarae F113, AmrZ and FleQ are general transcription factors that regulate multiple traits. It has also been shown that there is a common regulon shared by the two transcription factors. Moreover, these studies have shown that AmrZ and FleQ form a regulatory hub that inversely regulate traits such as motility, extracellular matrix component production, and iron homeostasis. The messenger molecule c-di-GMP plays an essential role in this hub since its production is regulated by AmrZ and it is sensed by FleQ and required for its regulatory role. This regulatory hub is functional both in culture and in the rhizosphere, indicating that the AmrZ-FleQ hub is a main player of P. ogarae F113 adaption to the rhizosphere environment, Work related to environmental adaption of pseudomonads in the authors’ laboratory is currently funded by a Spanish Ministerio de Ciencia e Innovación FEDER/EU Grant PID2021-125070OB-I00

Human trampling represents one of the main anthropogenic pressures in the rocky intertidal. This habitat includes many ecosystem engineers such as mussels that provide biogenic habitat and multiple services. This research assessed potential impacts of human trampling on beds of the mussel, Mytilus galloprovincialis, on NW shores of Portugal. To test for direct effects of trampling on mussels and indirect effects on the associated assemblages, three treatments were applied: control (untouched beds), low and high intensity of trampling. Effects of trampling were dependent on the taxa. Thus, values of shell length of M. galloprovincialis were greater under the highest intensity of trampling while abundances of Arthropoda, Mollusca and Lasaea rubra showed the opposite pattern. Moreover, total number of taxa and abundances of Nematoda and Annelida showed higher values under low trampling intensity. The implications of these results to manage human use in areas with ecosystem engineers are discussed

The potential interactions between the diverse pollutants that can be released into the environment and the resulting outcomes are a challenging issue that needs to be further examined. This in vitro study was aimed to assess potential toxic effects caused by combined exposure to tetrabromobisphenol A, a flame retardant widely used and frequently detected in aquatic matrices, and commercially available polystyrene nanoparticles as reference material to evaluate nanoplastics risks. Our results, using freshwater fish cell lines and a set of relevant cytotoxicity endpoints including cell viability, oxidative stress, and DNA damage, provide additional mechanistic insights that could help to fully characterize the toxicity profiles of tetrabromobisphenol A and polystyrene nanoparticles. Furthermore, we describe subtle changes in cell viability as well as the generation of oxidative DNA damage after coexposure to subcytotoxic concentrations of the tested pollutants, This work was funded by the Spanish Ministry of Science, Innovation and Universities / Spanish State Research Agency / _RTI2018–096046- B-C22. PSB has benefited from a contract from the Office of Education and Research of the Community of Madrid and the European Social Fund (PEJ-2019-AI/SAL-12775)

Cadmium (Cd) and mercury (Hg) are ubiquitous soil pollutants that promote the accumulation of reactive oxygen species, causing oxidative stress. Tolerance depends on signalling processes that activate different defence barriers, such as accumulation of small heat sock proteins (sHSPs), activation of antioxidant enzymes, and the synthesis of phytochelatins (PCs) from the fundamental antioxidant peptide glutathione (GSH), which is probably modulated by ethylene. We studied the early responses of alfalfa seedlings after short exposure (3, 6, and 24 h) to moderate to severe concentration of Cd and Hg (ranging from 3 to 30 μM), to characterize in detail several oxidative stress parameters and biothiol (i.e., GSH and PCs) accumulation, in combination with the ethylene signalling blocker 1-methylcyclopropene (1-MCP). Most changes occurred in roots of alfalfa, with strong induction of cellular oxidative stress, H2O2 generation, and a quick accumulation of sHSPs 17.6 and 17.7. Mercury caused the specific inhibition of glutathione reductase activity, while both metals led to the accumulation of PCs. These responses were attenuated in seedlings incubated with 1-MCP. Interestingly, 1-MCP also decreased the amount of PCs and homophytochelatins generated under metal stress, implying that the overall early response to metals was controlled at least partially by ethylene.

On the eve of the 100th anniversary of Dr. Warington’s discovery of boron (B) as a nutrient essential for higher plants, “boronists” have struggled to demonstrate a role beyond its structural function in cell walls dimerizing pectin molecules of rhamnogalacturonan II (RGII). In this regard, B deficiency has been associated with a plethora of symptoms in plants that include macroscopic symptoms like growth arrest and cell death and biochemical or molecular symptoms that include changes in cell wall pore size, apoplast acidification, or a steep ROS production that leads to an oxidative burst. Aiming to shed light on B functions in plant biology, we proposed here a unifying model integrating the current knowledge about B function(s) in plants to explain why B deficiency can cause such remarkable effects on plant growth and development, impacting crop productivity. In addition, based on recent experimental evidence that suggests the existence of different B ligands other than RGII in plant cells, namely glycolipids, and glycoproteins, we proposed an experimental pipeline to identify putative missing ligands and to determine how they would integrate into the above-mentioned model.

The seed morphology of three species belonging to the genus Bromheadia was analyzed under light and scanning electron microscopy. The seeds of B. cecieliae and B. truncata were studied for the first time. Differences in the qualitative and quantitative characteristics between the terrestrial B. finlaysoniana and the epiphytes B. cecieliae and B. truncata were observed, which were in concordance with the life form. Due to the variability of the seed shapes, a new methodology is proposed to analyze the distance between the embryo and the testa cells, with the aim of demonstrating the presence of air space within the seed. The method is compared to previous formulae used to measure free air space. Furthermore, a new measurement, the angle in twisted testa cells of epiphytic orchids, is proposed, to evaluate the degree of torsion in medial cells. Although the wide distribution of B. finlaysoniana could be related to the great buoyancy of their seeds in contrast to the limited distribution of B. cecieliae, we consider that environmental factors are more influential than the buoyancy of seeds when understanding the distribution of these taxa. Future studies on seeds morphology in orchid genera with terrestrial and epiphytic taxa will provide new insights into this research.

Tau is a cytoskeletal protein that is expressed mainly in neurons and is involved in several cellular processes, such as microtubule stabilization, axonal maintenance, and transport. Altered tau metabolism is related to different tauopathies being the most important Alzheimer’s disease where aberrant hyperphosphorylated and aggregated tau is found in the central nervous system. Here, we have analyzed that function in kidney by using tau knockout mice generated by integrating GFP-encoding cDNA into exon 1 of MAPT (here referred to as TauGFP/GFP). IVIS Lumina from PerkinElmer demonstrated GFP expression in the kidney. We then demonstrated by qPCR that the main tau isoform in the kidney is Tau4R. The GFP reporter allowed us to demonstrate that tau is found in the glomeruli of the renal cortex, and specifically in podocytes. This was further confirmed by immunohistochemistry. TauGFP/GFP mice present a podocyte cytoskeleton more dynamic as they contain higher levels of detyrosinated tubulin than wild-type mice. In addition, transmission electron microscopy studies demonstrated glomerular damage with a decrease in urinary creatinine. Our results prove that tau has an important role in kidney metabolism under normal physiological conditions, Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Work in the laboratory of JA is funded by grants from the Spanish Ministry of Economy and Competitiveness (PGC-2018-09177-B-100). Work in the laboratory of FH is funded by grants from the Spanish Ministry of Economy and Competitiveness (Ministerio de Economía, Industria y Competitividad, Gobierno de España, PID2020-113204GB-I00) and was co-fnanced from the Comunidad de Madrid through Structural Funds of the European Union [S2017/BMD-3700 (NEUROMETAB-CM)]

Salmonella enterica causes intracellular infections that can be limited to the intestine or spread to deeper tissues. In most cases, intracellular bacteria show moderate growth. How these bacteria face host defenses that recognize peptidoglycan, is poorly understood. Here, we report a high-resolution structural analysis of the minute amounts of peptidoglycan puri- fied from S. enterica serovar Typhimurium (S. Typhimurium) infecting fibroblasts, a cell type in which this pathogen undergoes moderate growth and persists for days intracellularly. The peptidoglycan of these non-proliferating bacteria contains atypical crosslinked muropep- tides with stem peptides trimmed at the L-alanine-D-glutamic acid-(γ) or D-glutamic acid-(γ)- meso-diaminopimelic acid motifs, both sensed by intracellular immune receptors. This pepti- doglycan has a reduced glycan chain average length and ~30% increase in the L,D-cross- link, a type of bridge shared by all the atypical crosslinked muropeptides identified. The L,D- transpeptidases LdtD (YcbB) and LdtE (YnhG) are responsible for the formation of these L, D-bridges in the peptidoglycan of intracellular bacteria. We also identified in a fraction of muropeptides an unprecedented modification in the peptidoglycan of intracellular S. Typhi- murium consisting of the amino alcohol alaninol replacing the terminal (fourth) D-alanine. Alaninol was still detectable in the peptidoglycan of a double mutant lacking LdtD and LdtE, thereby ruling out the contribution of these enzymes to this chemical modification. Remark- ably, all multiple mutants tested lacking candidate enzymes that either trim stem peptides or form the L,D-bridges retain the capacity to modify the terminal D-alanine to alaninol and all attenuate NF-κB nuclear translocation. These data inferred a potential role of alaninol-con- taining muropeptides in attenuating pro-inflammatory signaling, which was confirmed with a synthetic tetrapeptide bearing such amino alcohol. We suggest that the modification of D- alanine to alaninol in the peptidoglycan of non-proliferating intracellular S. Typhimurium is an editing process exploited by this pathogen to evade immune recognition inside host cells., This work was funded by grants PID2020-112971GB-I00/10.13039/501100011033 (F.G-dP.) and PID2019-104070RB-C21 (S.V.) of the Spanish Ministry of Science and Innovation, VR2018-02823 of the Swedish Research Council (F.C.), KAW2012.0184 of the Knut and Alice Wallenberg Foundation (F.C.), and SMK2062 of the Kempe Foundation (F.C.). S.C. was recipient of an EMBO Short-Term Fellowship number 6426 for a stay in the lab of F.C. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 20-01-2022, La tetraspanina CD9 es capaz de interaccionar con multitud de moléculas, entre ellas la integrina α5β1 y la metaloproteasa ADAM17, y a través de estas interacciones puede regular distintos procesos celulares, entre ellos la adhesión celular. Las interacciones entre la integrina α5β1 y la metaloproteasa ADAM17 pueden ocurrir en la misma célula (interacción en cis) o pueden ocurrir en células distintas (interacción en trans). Esta Tesis Doctoral se ha centrado en estudiar cómo la tetraspanina CD9 regula negativamente la adhesión celular mediada por la integrina α5β1: al aumentar la interacción en cis con ADAM17 en la superficie celular y la interacción entre CD9, ADAM17 y la integrina α5β1 en la unión y captación de exosomas. De igual manera, hemos demostrado, que el anticuerpo monoclonal 2A10, que reconoce el dominio desintegrina de ADAM17; inhibe la adhesión celular de la integrina α5β1 a su ligando fibronectina. Por otra parte, los exosomas son nanovesículas que tienen un origen endosomal. Otros grupos de investigación han demostrado que exosomas derivados de células cancerosas juegan un papel en muchos procesos relacionados con la metástasis. Sin embargo, no se había estudiado que el papel que juega la interacción entre CD9-α5β1-ADAM17 en la unión, captación y fusión de los exosomas a células tumorales. Hemos demostrado que la interacción entre la integrina α5β1 en células colorrectales tumorales y células mesoteliales primarias, y su ligando ADAM17 en los exosomas está mediando adhesión y la captación de exosomas a células tumorales colorrectales y a células mesoteliales derivadas de pacientes con cáncer de ovario; y que estos procesos están negativamente regulados por la expresión de la tetraspanina CD9 en los exosoma

Rhizosphere colonization by bacteria involves molecular and cellular mechanisms, such as motility and chemotaxis, biofilm formation, metabolic versatility, or biosynthesis of secondary metabolites, among others. Nonetheless, there is limited knowledge concerning the main regulatory factors that drive the rhizosphere colonization process. Here we show the importance of the AmrZ and FleQ transcription factors for adaption in the plant growth-promoting rhizobacterium (PGPR) and rhizosphere colonization model Pseudomonas ogarae F113. RNA-Seq analyses of P. ogarae F113 grown in liquid cultures either in exponential and stationary growth phase, and rhizosphere conditions, revealed that rhizosphere is a key driver of global changes in gene expression in this bacterium. Regarding the genetic background, this work has revealed that a mutation in fleQ causes considerably more alterations in the gene expression profile of this bacterium than a mutation in amrZ under rhizosphere conditions. The functional analysis has revealed that in P. ogarae F113, the transcription factors AmrZ and FleQ regulate genes involved in diverse bacterial functions. Notably, in the rhizosphere, these transcription factors antagonistically regulate genes related to motility, biofilm formation, nitrogen, sulfur, and amino acid metabolism, transport, signalling, and secretion, especially the type VI secretion systems. These results define the regulon of two important bifunctional transcriptional regulators in pseudomonads during the process of rhizosphere colonization.

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 10-01-2022, Este trabajo se ha llevado a cabo mediante financiación concedida por los siguientes organismos: Comunidad de Madrid y Fondo Social Europeo (PEJ-2017-AI/AMB-6229), Ministerio de Ciencia, Innovación y Universidades (CGL2015-66242-R y PID2019-10481266GB-I00) y Programa Erasmus+ 2019/2020

Evaluating data quality and inventory completeness must be a preliminary step inany biodiversity research, particularly in the case of insects and high biodiversityareas. Yet, this step is often neglected or, at best, assessed only for one insectgroup, and the degree of congruence of sampling effort ffor different insect groupsremains unexplored. We assess the congruence in the spatial distribution of sampling effort for fiveinsect groups (butterflies, caddisflies, dung beetles, moths, and aquatic beetles) inthe Iberian Peninsula. We identify well-surveyed areas for each taxonomic groupand examine the degree to which the patterns of sampling effort can be explainedby a set of variables related to environmental conditions and accessibility. Irrespective of the general lack of reliable inventories, we found a general but lowcongruence in the completeness patterns of the different taxa. This suggests thatthere is not a common geographical pattern in survey effort and that idiosyncraticand contingent factors (mainly the proximity to the workplaces of entomologists)are differentially affecting each group. After many decades of taxonomic and faunistic work, distributional databases ofIberian insects are still in a very preliminary stage, thus limiting our capacity toobtain reliable answers to basic and applied questions. We recommend carrying out long-term, standardised and well-designed entomolog-ical surveys able to generate a reliable image of the distribution of different insect groups. This will allow us to estimate accurately insect trends and better under-stand the full extent of global biodiversity loss., This study has been supported by the projects BioWeb (MINECO:CGL2011-15622-E BOS), BANDENCO (JCMM: POII11-0277-5747)and IBERARTRO (SBPLY/17/180501/000492) founded by European Regional Development Fund (ERDF) through the Consejería de Educación, Ciencia y Cultura, Junta de Comunidades de Castilla-La Mancha. David Sánchez-Fernández is funded by a postdoctoral contract fromthe Spanish Ministry of Science and Innovation (Ramón y Cajal program; RYC2019-027446-I

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 29-03-2022, Las células B convencionales juegan un papel crucial como eje del sistema inmunitario adaptativo humoral. Adicionalmente a estas funciones, se ha propuesto que las células B pueden presentar antígenos mediante presentación cruzada, aunque, tanto las vías de captura de estos antígenos, como las propias fuentes de antígenos no se encuentran bien definidas. En este trabajo describimos cómo las células B pueden capturar bacterias enteras a partir de células dendríticas (DCs) infectadas mediante un proceso denominado transfagocitosis. El contacto estrecho entre ambos tipos celulares es fundamental para que se dé el proceso y es independiente del tipo bacteriano. Al mismo tiempo, la activación de las células B facilita la transfagocitosis. La exposición a las bacterias intracelulares “entrena” a las células B (a partir de ahora Bbac; de células B entrenadas por bacterias) que adquieren nuevas habilidades como células presentadoras de antígenos. Una vez las bacterias se encuentran en el interior de las células B, se degradan eficazmente y los péptidos resultantes de la degradación se presentan mediante presentación cruzada a células T CD8+ vírgenes, que se activan de forma muy potente. No obstante, para que adquieran estas habilidades como células presentadoras, las células Bbac deben mantener una actividad autofágica adecuada. Nuestros datos demuestran que la activación de la respuesta T CD8+ citotóxica mediada por la actividad presentadora de antígenos de las células Bbac ayuda, tanto a resolver infecciones bacterianas, como a limitar el crecimiento tumoral. Por tanto, nuestros datos abren el camino para la creación de una nueva generación de inmunoterapias basadas en las células Bbac en la lucha contra el cáncer y contra patógenos intracelulares, Este trabajo ha sido llevado a cabo con financiación del Ministerio de Ciencia e Innovación con referenciaMCIN/AEI/10.13039/501100011033/

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 22-09-2022, Las neoplasias linfoblásticas de células T son enfermedades hematológicas agresivas que derivan de linfoblastos comprometidos con el linaje de células T que se desarrollan principalmente en niños. Esta enfermedad afecta a la médula ósea y a la sangre (T-ALL) aunque también puede aparecer como una masa tumoral en el timo/mediastino o en los nódulos linfáticos (T-LBL). La toxicidad asociada a los tratamientos actuales y el mal pronóstico en caso de recaída, con tasas de supervivencia inferiores al 10%, ponen de manifiesto la necesidad de nuevas terapias personalizadas que resulten más eficaces y generen menos efectos adversos. La vía de STAT5 es la segunda vía de señalización más frecuentemente desregulada en las TALL/LBL solamente por detrás de la vía de NOTCH. En este sentido, un alto número de pacientes muestra la fosforilación sostenida y consiguiente activación constitutiva de STAT5, que se transloca al núcleo, donde actúa como un factor de transcripción y promueve el desarrollo tumoral. Lamentablemente, todavía no existe un tratamiento específico para aquellos pacientes diagnosticados con T-ALL/LBL que presentan desregulada la vía de STAT5. Por un lado, porque la inhibición de STAT5 resulta complicada en términos de eficacia y especificidad. Por otro lado, porque las alteraciones que promueven la fosforilación sostenida de STAT5 afectan a múltiples genes, pueden aparecer de forma simultánea y no han sido caracterizadas en su totalidad, complicando la implementación de nuevas terapias. El objetivo general de la presente Tesis Doctoral es la caracterización de las bases moleculares subyacentes a las neoplasias linfoblásticas de células T, para identificar potenciales dianas terapéuticas que permitan el desarrollo de nuevos tratamientos personalizados dirigidos a aquellos pacientes diagnosticados con T-ALL/LBL que presenten una activación constitutiva de STAT5. La primera parte del trabajo ha consistido en la identificación y caracterización funcional de alteraciones susceptibles de contribuir a la fosforilación sostenida de STAT5 en los pacientes con neoplasias linfoblásticas de células T, entre las que se encuentran: la fusión SEPTIN6-ABL2, la hipermetilación de la isla CpG asociada con el inicio de la transcripción de SOCS3 y diferentes mutaciones puntuales que afectan a los genes JAK1, JAK3 y el propio STAT5. En base a los resultados obtenidos, la segunda parte del trabajo se ha enfocado en el estudio de los mecanismos moleculares por los que una fosforilación sostenida de STAT5 promueve el desarrollo tumoral en los pacientes con T-ALL/LBL. En este sentido, nuestros resultados demuestran que la activación constitutiva de STAT5 induce un perfil de expresión génica alterado con niveles de tránscritos aberrantes para múltiples genes. Entre ellos, la sobreexpresión de PIM1 tiene un efecto directo en la señalización relativa a c-MYC y mTOR, resultando fundamental para la proliferación y viabilidad de aquellas células que presentan mutaciones oncogénicas en la vía de STAT5. Por lo tanto, PIM1 se postula como una diana terapéutica para la implementación de nuevos tratamientos dirigidos a aquellos pacientes diagnosticados con T-ALL/LBL que muestren una activación constitutiva de STAT5 causada por la presencia de diferentes alteraciones en su vía de señalización, Para el desarrollo de la tesis se ha contado con financiación procedente de los siguientes proyectos:SAF2015-70561-R. Proyecto de investigación del Ministerio de Economía y Competitividad. IPs: Prof. José Fernández-Piqueras y Dra. María Villa Morales. RTI2018093330-B-I00. Proyecto de investigación del Ministerio de Ciencia e Innovación. IPs: Prof. José Fernández-Piqueras y Prof. Javier Santos Hernández. AECC-PROYECT18054PIRI. Proyecto de investigación de la Asociación Española Contra el Cáncer. IP: Prof. José Fernández-Piqueras

We estimated the potential impact of Global Warming on the species richness of Iberian butterflies. First, we determined the grid size that maximized the balance between geographic resolution, area coverage and environmental representativeness. Contemporary richness was modelled in several alternative ways that differed in how sampling effort was controlled for, and in whether the non-climatic variables (physiography, lithology, position) were incorporated. The results were extrapolated to four WorldClim scenarios. Richness loss is to be expected for at least 70% of the area, with forecasts from the combined models being only slightly more optimistic than those from the purely climatic ones. Overall, the most intense losses are predicted for areas of highest contemporary species richness, while the potential slightly positive or nearly neutral changes would most often concentrate in cells of low to moderate present richness. The environmental determinants of richness might not be uniform across the geographical range of sampling effort, suggesting the need of additional data from the least intensively surveyed areas., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was partly funded by JJ CC Castilla—La Mancha (Spain), Project SBPLY/17/180501/000492 and MINECO, Project CGL2017-86926-P

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM, For more than five decades, research has been conducted at Ny-Ålesund, in Svalbard, Norway, to understand the structure and functioning of High-Arctic ecosystems and the profound impacts on them of environmental change. Terrestrial, freshwater, glacial and marine ecosystems are accessible year-round from Ny-Ålesund, providing unique opportunities for interdisciplinary obser-vational and experimental studies along physical, chemical, hydrological and climatic gradients. Here, we synthesize terrestrial and freshwater research at Ny-Ålesund and review current knowledge of biodiversity patterns, species population dynamics and interactions, ecosystem processes, biogeochemical cycles and anthropogenic impacts. There is now strong evidence of past and ongoing biotic changes caused by climate change, including negative effects on populations of many taxa and impacts of rain-on-snow events across multiple trophic levels. While species-level characteristics and responses are well under-stood for macro-organisms, major knowledge gaps exist for microbes, inverte-brates and ecosystem-level processes. In order to fill current knowledge gaps, we recommend (1) maintaining monitoring efforts, while establishing a long-term ecosystem-based monitoring programme; (2) gaining a mechanistic under-standing of environmental change impacts on processes and linkages in food webs; (3) identifying trophic interactions and cascades across ecosystems; and (4) integrating long-term data on microbial, invertebrate and freshwater com-munities, along with measurements of carbon and nutrient fluxes among soils, atmosphere, freshwaters and the marine environment. The synthesis here shows that the Ny-Ålesund study system has the characteristics needed to fill these gaps in knowledge, thereby enhancing our understanding of High-Arctic ecosystems and their responses to environmental variability and change

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 13-07-2022

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 15-07-2022, Historically, neuromelanin (NM) has been considered a waste product of catecholaminergic metabolism. A key feature of NM, as well as all other melanins, is related to their heterocyclic ring-structure with conjugated double bonds that creates a π-bond system across multiple atoms that lowers the energy and stabilizes the molecule. Due to this conformation, melanins have been attributed with many functionalities from which stands out its ability to trap UV–light, free radicals, toxins, and metals. The presence in human brain of NM at localizations related to the main neurodegeneration foci, such as the sustantia nigra (SN) in Parkinson's disease (PD) and the locus coeruleous (LC) in Alzheimer's disease (AD), together with NM ability to absorb free radicals and chelate metals and drugs suggest a physiological role of NM in neurodegeneration. However, despite several reports suggesting the involvement of NM in neurodegenerative disorders, the molecular basis for such observations remains largely unknown. The focus of this doctoral thesis is the molecular and functional characterization of NM and three analogs based on three catecholamines potentially precursors of its synthesis in the brain. The results are divided into chapters composed of several experimental studies, focusing on the characterization at the molecular and functional level of NM and its analogs, while developing new approaches and methodologies for NM analysis. Since NM is a dynamic and complex substance with an undefined composition, as NM proxies, we selected three analogs produced by the oxidation of three catecholamines involved in NM synthesis: pLD, pDA and pNA from L-DOPA, DA or NA, respectively. In this work, by using a repertoire of techniques (thioflavin T aggregation kinetics, transmission electronic microscopy, transgenic C. elegans in vivo model), we demonstrated that NM analogs interact and modulate the aggregation kinetics of amyloid-prone proteins, pointing directly to one of the potential key roles of NM in neurodegeneration. We have also developed monoclonal antibodies against NM as a valuable biochemical tool for in vitro and ex-vivo NM characterization. Although the production of monoclonal antibodies is generally highly standardized for proteins, we were confronted with a polymeric substance with a nature very different from protein antigens that compelled us to develop alternative strategies for immunization by using NM coated to silica beads and an extended immunization protocol. Moreover, through plasma analysis by affinity chromatography and co-immunoprecipitation of NM, we have identified a subset of NM binding proteins and characterized their potential interaction mechanisms. Functional pathways analysis indicated that NM could interfere with inflammation and vascular processes, cytoplasm organization and the respiratory chain. All this events have been linked to AD and PD pathophysiology. Additionally, the use of cell cultures allowed us to study the cytotoxicity and proinflammatory effects triggered by NM. We have found that NM presents a characteristic fluorescence spectrum that can be exploited for the sensitive label-free detection of this substance in brain tissue. However, lipofuscin (LF) aggregates, another aging pigment, also presents an intense fluorescence throughout the brain tissue. By using confocal microscopy with specific settings for the collection of emission spectra in the near infrared region and the use of time-resolved fluorescence, we developed new methodologies to characterize the properties and distribution of NM, distinguishing structures composed of NM, LF or both. The data gathered in this thesis, together with previous findings, provide clues on the role of NM on neurodegenerative processes, changing the NM concept from metabolic “garbage” to an active substance, which is a key actor with a dual role in the physiopathology of neurodegeneration, El trabajo realizado en esta tesis ha sido financiado por Proyecto Mineco “Retos Investigación” miRNA and lipid metabolism markers as potential links between vascular dysfunction and Alzheimer’s pathophysiology. Entidad de realización: CIBER ENFERMEDADES NEURODEGENERATIVAS (CIBERNED). Investigadores: Miguel Medina Padilla (IP); Miguel Calero Lara (Co-IP); Olga Calero Rueda; Luis García Albert; Victoria López Alonso. Convocatoria de Proyectos I+D+i «Retos Investigación». Fecha de inicio-fin: 01/01/2017 - 31/12/2019 y Proyecto Colaborativo Ciberned Neurodegeneración ligada a la neuromelanina en la enfermedad de Parkinson: implicaciones mecanísticas, diagnósticas y terapéuticas. Entidad de realización: CIBER ENFERMEDADES NEURODEGENERATIVAS (CIBERNED) Investigadores principales: Miquel Vila, Ramón Trullás, José Luis Lanciego, José Luis Labandeira, Miguel CalNombre del programa: Proyectos Colaborativos CIBERNED. Fecha de inicio-fin: 01/01/2021 - 31/12/2022

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 01-07-2022, La enfermedad de Huntington (EH) es un trastorno neurodegenerativo hereditario con afectación de los ganglios basales para el cual no existe tratamiento. Las proteínas de unión a elementos de poliadenilación citoplásmica (CPEB1-4) son una familia de proteínas que regulan la traducción de ARN mensajeros (ARNm) específicos induciendo alargamiento o acortamiento de la longitud de la cola de poli(A). Al caracterizar el estatus de las CPEBs y la poliadenilación global del ARNm en modelos animales de la EH, observamos una marcada deadenilación del transcrito de Slc19a3 (que codifica para el transportador de tiamina 2, ThTr2). Mutaciones en SLC19A3 causan la enfermedad de ganglios basales sensible a biotina y tiamina (BTBGD), un trastorno neurológico devastador con afectación estriatal que puede ser revertido con un tratamiento de altas dosis de biotina y tiamina. Por tanto, la observación de una deadenilación de Slc19a3 evidenció que los pacientes con la EH podrían sufrir una deficiencia de tiamina asociada a SLC19A3. Lo cual, además, sugería que los pacientes con la EH podrían beneficiarse de la terapia vitamínica que corrige la BTBGD. El primer objetivo de la presente tesis fue evaluar si la EH cursa con déficit de ThTr2 y una consiguiente deficiencia de tiamina. Se encontró una disminución en los niveles de proteína de ThTr2 en el cerebro de los individuos con la EH. Además, al igual que en los pacientes de BTBGD, los individuos con la EH mostraron una disminución de tiamina en el líquido cefalorraquídeo (LCR), específicamente, de tiamina monofostato (TMP), lo cual además podría tener valor como biomarcador de progresión de la enfermedad. Asimismo, los individuos con la EH mostraron una disminución en las concentraciones estriatales de tiamina pirofosfato (TPP), la forma metabólicamente activa de la tiamina. Para un estudio preclínico del potencial de la suplementación con tiamina para la EH, se evaluaron los niveles de ThTr2 y tiamina en ratones modelo de la EH. Al igual que en los pacientes, en los ratones modelo de la EH se observó una disminución de ThTr2 y de la concentración de TPP. Esto nos llevó a administrar biotina y tiamina a altas dosis (en el rango de las que se administran a los pacientes con BTBGD) a los ratones modelo de la EH. El tratamiento fue capaz de atenuar la deficiencia de tiamina y de mejorar el fenotipo radiológico, neuropatológico y motor de los ratones. Finalmente, se estudió la posible conexión mecanística entre la descrita alteración de las CPEBs y la disminución patogénica de ThTr2. Pudimos concluir que la disminución de CPEB4 es suficiente para inducir la disminución de la poliadenilación del ARNm de SLC19A3 y que corregir los niveles de CPEB4 mejora los niveles de ThTr2 y el fenotipo de los ratones EH. En su conjunto, estos datos demuestran que la EH cursa con deficiencia de tiamina y, a la vista de las mejoras comportamentales y neuroanatómicas de los modelos animales tras la suplementación con biotina y tiamina, sugieren una terapia fácil de implementar en los pacientes con EH

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 04-03-2022

Optical coherence tomography (OCT) is an imaging technique currently used in clinical practice to obtain optical biopsies of different biological tissues in a minimally invasive way. Among the contrast agents proposed to increase the efficacy of this imaging method, gold nanoshells (GNSs) are the best performing ones. However, their preparation is generally time-consuming, and they are intrinsically costly to produce. Herein, we propose a more affordable alternative to these contrast agents: Bi2Se3 nanostructured clusters with a desert rose-like morphology prepared via a microwave-assisted method. The structures are prepared in a matter of minutes, feature strong near-infrared extinction properties, and are biocompatible. They also boast a photon-to-heat conversion efficiency of close to 50%, making them good candidates as photothermal therapy agents. In vitro studies evidence the prowess of Bi2Se3 clusters as OCT contrast agents and prove that their performance is comparable to that of GNSs, J.Y. acknowledges the support from the China Scholarship Council (CSC file no. 201704910867). R.M. acknowledges the support of the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant agreement no. 797945 (LANTERNS). This work was supported by the Spanish Ministry of Economy and Competitiveness under projects MAT2017-83111R, MAT2017-85617-R, and PID2019- 106211RB-I00, by the Instituto de Salud Carlos III (PI16/ 00812), by the Comunidad Autonoma de Madrid (B2017/ ́ BMD-3867 RENIM-CM), and cofinanced by the European Structural and Investment Fund

The phenomenal advances in sequencing techniques and analytical development during the last decade have provided a unique opportunity to unravel the evolutionary history of lineages under complex patterns of evolution. This is the case of the largest clade of the ginseng family (Araliaceae), the Asian Palmate group (AsPG), where the large internal polytomies and genome incongruences detected in previous studies pointed to a scenario of radiation with hybridization events between genera for the early evolution of the group. In this study, we aim to obtain well‐resolved nuclear and plastid phylogenies of the AsPG using Hyb‐Seq to evaluate the radiation hypothesis and assess the role of hybridization in the early evolution of the group. We performed concatenated‐ and coalescent‐based phylogenetic analyses from the 936 targeted nuclear loci and 261 plastid loci obtained for 72 species representing 20 genera of the AsPG and the main clades of Araliaceae. The impact of hybridization and incomplete lineage sorting (ILS) was assessed with SNaQ, and genome duplications were evaluated with ChromEvol. Our nuclear and plastid phylogenies are compatible with a scenario of early radiation in the AsPG. Also, the identification of extensive signals of hybridization and ILS behind the genome incongruences supports hybridization as a major driving force during the early radiation. We hypothesize a whole‐genome duplication event at the origin of the AsPG, followed by a radiation that led to extensive ILS, which, alongside the early inter‐genera hybridization, is obscuring the phylogenetic signal in the early evolution of this major clade, This study was financed in part by the Spanish Ministry of Economy, Industry, and Competitiveness (CGL2017‐87198‐P), the Spanish Ministry of Science and Innovation (PID2019‐106840GA‐C22), the Laboratories of Analytical Biology of the Smithsonian Institution, and the Smithsonian Institution DNA Barcode Network. A. Gallego‐Narbón was supported by the program “Contratos predoctorales para Formación de Personal Investigador FPI‐ UAM” of Universidad Autónoma de Madrid (FPI‐UAM 2018) and the Smithsonian Institution Fellowship Program (SIFP)

AGC1/Aralar/Slc25a12 is the mitochondrial carrier of aspartate-glutamate, the regulatory component of the NADH malate-aspartate shuttle (MAS) that transfers cytosolic redox power to neuronal mitochondria. The deficiency in AGC1/Aralar leads to the human rare disease named “early infantile epileptic encephalopathy 39” (EIEE 39, OMIM # 612949) characterized by epilepsy, hypotonia, arrested psychomotor neurodevelopment, hypo myelination and a drastic drop in brain aspartate (Asp) and N-acetylaspartate (NAA). Current evidence suggest that neurons are the main brain cell type expressing Aralar. However, paradoxically, glial functions such as myelin and Glutamine (Gln) synthesis are markedly impaired in AGC1 deficiency. Herein, we discuss the role of the AGC1/Aralar-MAS pathway in neuronal functions such as Asp and NAA synthesis, lactate use, respiration on glucose, glutamate (Glu) oxidation and other neurometabolic aspects. The possible mechanism triggering the pathophysiological findings in AGC1 deficiency, such as epilepsy and postnatal hypomyelination observed in humans and mice, are also included. Many of these mechanisms arise from findings in the aralar-KO mice model that extensively recapitulate the human disease including the astroglial failure to synthesize Gln and the dopamine (DA) mishandling in the nigrostriatal system. Epilepsy and DA mishandling are a direct consequence of the metabolic defect in neurons due to AGC1/Aralar deficiency. However, the deficits in myelin and Gln synthesis may be a consequence of neuronal affectation or a direct effect of AGC1/Aralar deficiency in glial cells. Further research is needed to clarify this question and delineate the transcellular metabolic fluxes that control brain functions. Finally, we discuss therapeutic approaches successfully used in AGC1-deficient patients and mice.

The Iberian Pyrite Belt (IPB) is one of the largest deposits of sulphidic minerals on Earth. Río Tinto raises from its core, presenting low a pH and high metal concentration. Several drilling cores were extracted from the IPB’s subsurface, and strain T2.3D-1.1 was isolated from a core at 121.8 m depth. We aimed to characterize this subterranean microorganism, revealing its phylogenomic affiliation (Average Nucleotide Identity, digital DNA-DNA Hybridization) and inferring its physiology through genome annotation, backed with physiological experiments to explore its relationship with the Fe biogeochemical cycle. Results determined that the isolate belongs to the Shewanella putrefaciens (with ANI 99.25 with S. putrefaciens CN-32). Its genome harbours the necessary genes, including omcA mtrCAB, to perform the Extracellular Electron Transfer (EET) and reduce acceptors such as Fe3+, napAB to reduce NO3− to NO2−, hydAB to produce H2 and genes sirA, phsABC and ttrABC to reduce SO32−, S2O32− and S4O62−, respectively. A full CRISPR-Cas 1F type system was found as well. S. putrefaciens T2.3D-1.1 can reduce Fe3+ and promote the oxidation of Fe2+ in the presence of NO3− under anaerobic conditions. Production of H2 has been observed under anaerobic conditions with lactate or pyruvate as the electron donor and fumarate as the electron acceptor. Besides Fe3+ and NO3−, the isolate also grows with Dimethyl Sulfoxide and Trimethyl N-oxide, S4O62− and S2O32− as electron acceptors. It tolerates different concentrations of heavy metals such as 7.5 mM of Pb, 5 mM of Cr and Cu and 1 mM of Cd, Co, Ni and Zn. This array of traits suggests that S. putrefaciens T2.3D-1.1 could have an important role within the Iberian Pyrite Belt subsurface participating in the iron cycle, through the dissolution of iron minerals and therefore contributing to generate the extreme conditions detected in the Río Tinto basin, The authors acknowledge the support of project PID2019-104812GB-100 from Ministerio de Ciencia e Innovación. G.M acknowledges the support from the grant PRE2020-091940 and A.M.B from the grant FPU19/01743

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 07-06-2022, Postembryonic development in plants constitutes a unique situation to study how the behavior of different cell types is coordinated to form all organs continuously throughout the life of the organism. Specifically, the Arabidopsis root apical meristem (RAM) is an organ, rich in proliferating cells of few cell types organized in concentric layers and with a gradual longitudinal transition from stem cells to differentiated tissues. Using a three-color cell cycle marker developed in our laboratory alongside other experimental strategies, we have begun to characterize cell cycle dynamics in the RAM. We have found that the total cell cycle length and also individual phases change depending on the tissue layers and, most notably, throughout the developmental trajectory. The G1 duration can vary between 1-2 hours in cells about to leave the root meristem and more than 20 hours in cells close to the stem cell niche, following a proximal-distal gradient that coincides with concentrations of the well-known stem cell regulator PLETHORA (PLT). Here, we have uncovered a link between developmental cues and cell cycle genes. In the regulatory network proposed, PLT proteins act upon RETINOBLASTOMA RELATED 1 (RBR1) phosphorylation by the CDK inhibitor KRP5, lengthening G1 duration by inhibiting G1/S transition

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 01-04-2022, Non-vesicular lipid transfer at ER and plasma membrane (PM) contact sites (CS) is crucial for the maintenance of membrane lipid homeostasis. Extended synaptotagmins (E-Syts) play a central role in this process as they act as molecular tethers of ER and PM and as lipid transfer proteins between these organelles. E-Syts are proteins constitutively anchored to the ER through an N-terminal hydrophobic segment and bind the PM via a variable number of C-terminal C2 domains. Synaptotagmins (SYTs) are the plant orthologous of E-Syts and regulate the ER–PM communication in response to abiotic stress. Combining different structural and biochemical techniques, we demonstrate that the binding of SYT1 to lipids occurs through a Ca2+-dependent lipid-binding site and by a site for phosphorylated forms of phosphatidylinositol, thus integrating two different molecular signals in response to stress. In addition, we show that SYT1 displays three highly flexible hinge points that provide conformational freedom to facilitate lipid extraction, protein loading, and subsequent transfer between PM and ER, El transporte de lípidos no vesicular en los sitios de contacto (CSs, del ingés “Contact Sites”) entre la membrana plasmática (MP) y el retículo endoplasmático (RE) es crucial para el mantenimiento de la homeostasis lipídica. Las Sinaptotagminas extendidas (E-Syts, “Extended Synaptotagmins”) juegan un papel fundamental en este proceso al actuar como conectores moleculares entres el RE y la MP y como proteínas transportadoras de lípidos entre ambos orgánulos. Las E-Syts están constitutivamente ancladas al RE a través de su segmento hidrofóbico N-terminal y unen la MP a través de un número variable de dominios C2 en su extremo C-terminal. Las Sinaptotagminas de plantas (SYTs) son ortólogas de las E-Syts y regulan la comunicación entre el RE y la MP en respuesta al estrés abiótico. A través de diferente técnicas estructurales y bioquímicas demostramos que la unión de SYT1 a lípidos ocurre a través de un sitio de unión a lípidos dependiente de Ca2+ y de un sitio para formas fosforiladas de fosfatidilinositol y, por tanto, integra dos señales bioquímicas distintas en respuesta a estrés. Adicionalmente, mostramos que SYT1 presenta tres puntos de bisagra flexibles que proporcionan a la proteína la libertad conformacional necesaria para facilitar la extracción lipídica de la membrana, la carga lipídica y el transporte entre el RE y la MP

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 18-07-2022, Morphogenesis is, largely, an embryonic developmental process through which individual cells, tissues and organs acquire a specific size and shape that as whole conform the outline of a given organism. Morphogenetic rearrangements take place in basically all embryonic tissues, although to a different extent and in distinct scenarios. Despite this diversity, the underlying mechanisms involve biochemical inputs and mechanical forces, which are applied at the single cell level, but result in coordinated robust, large-scale, spatio-temporal patterns at the tissue or organ scale. Understanding how these integrated patterns co-ordinately arise to originate a viable organism is one of the still unresolved issues in developmental biology. This thesis has been designed with the overarching goal of investigating the molecular basis of these integrated patterns during embryonic morphogenesis, using the zebrafish as a model system. In particular, we have addressed whether and how VGLL4, a co-transcriptional factor, contributes to three critical morphogenetic events: epiboly, anterior-posterior axis elongation and eye cup formation. The rationale for this study relays on the notion that VGLL4 seems to act as competitor of YAP1, one of the most studied mechano-transducer proteins. Taking advantage of CRISPR-Cas9 technology, we have first generated single and compound zebrafish vgll4 mutant lines for the three existing zebrafish paralogues: vgll4a, vgll4b and vgll4l. Using a battery of molecular, cellular and imaging approaches, we show that the maternal component of vgll4a is required for timely and coherent epibolic movements during gastrulation. vgll4a controls proper E-cadherin/β-catenin distribution at the blastomere plasma membrane upstream of Yap1 activation, indicating that vgll4a supports, rather than antagonise, Yap1 signalling, at least in this context. We further show that the zygotic form of a different vgll4 paralogue, vgll4b, is a novel piece of the gene regulatory network that controls anterior-posterior axis elongation. Its function seems required within committed mesodermal progenitors, likely by repressing tbx16 activity, which, in turn, supports the development of the somitic mesoderm. Finally, we provide evidence that Yap1 is required to maintain RPE integrity during optic cup morphogenesis, whereas vgll4 paralogues could down-regulate proliferation of the retinal neuroepithelium. Taken together, these data provided novel information on embryonic morphogenesis, showing different and context dependent functions for vgll4, which are dependent or independent from Yap1 activity. From a broader perspective our results may impact on our understanding of congenital malformations or pathological conditions such as primary or metastatic tumours, given the known implication of yap1 and vgll4 in these conditions, The experimental work was supported by Grants BFU2016-75412-R, PID2019-104186RB-I00 and RED2018-102553-T funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union” to PB. Institutional grants from the Fundación Ramón Areces and Banco de Santander to the CBMSO are also acknowledged

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de Lectura: 16-03-2022, De acuerdo a los trabajos que se han publicado desde los inicios de la Biología Evolutiva, entender qué factores favorecen los procesos de especiación y extinción, y el cuándo y por qué ocurren cambios drásticos en dichos procesos, es uno de los principales objetivos de esta rama de la Biología. A lo largo de esta tesis se emplean diferentes métodos para estimar las tasas de especiación y extinción, identificar posibles eventos de extinción masiva, y la asociación entre la aparición de algunos caracteres y cambios en la dinámica de la diversificación de linajes, para entender la historia evolutiva de los coleópteros v esicantes, familia Meloidae. De forma paralela, se incrementa el conocimiento taxonómico y biogeográfico y biólogico del grupo de estudio. Los resultados sugieren que los procesos de especiación en Meloidae pueden ser tanto de naturaleza adaptativa como no adaptativa, y que la evolución de algunos rasgos del ciclo de vida es responsable de la diversidad táxica actual de la familia. También hemos encontrado que algunos rasgos o estrategias de vida están asociados a elevadas tasas de extinción históricas, lo que supone un mayor riesgo de extinción en el presente (“extinction debt”). Finalmente se obtiene evidencia de que algunos linajes dentro de la familia, experimentaron la pérdida de restricciones genéticas, selectivas, funcionales o de desarrollo, es decir, de restricciones evolutivas que daban forma a estructuras como los élitros y el abdomen. Esto permitió la exploración de nuevos fenotipos, que dio lugar a una copiosa diversidad morfológica. A través de este caso de estudio se puede entender mejor y cuantificar las consecuencias que alteraciones en las restricciones evolutivas pueden tener en la evolución morfológica. Finalmente, se establecen los límites de la distribución geográfica de Spastonyx nemognathoides, un taxón con una historia taxonómica compleja y se revisa la fauna de Epicauta en Venezuela, Esta tesis se realizó con los recursos económicos otorgados por el Ministerio de Ciencia e Innovación, MICINN, ( antiguamente Ministerio de Economía y Competitividad, MINECO) y por el Fondo Europeo de Desarrollo Regional (FEDER) a los proyectos CGL2015-66571-P y PID2019- 1 10243GB-I00 concedidos a Mario García París por la Agencia Española de Investigación

El contenido del artículo versa sobre el origen, la evolución y actividades, así como las perspectivas futuras de la Real Sociedad Española de Historia Natural (RSEHN), que es la sociedad científica privada más antigua que existe en España. Un grupo de entusiastas naturalistas, a la cabeza de los cuales hay que situar al catedrático de zoología Laureano Pérez Arcas, la fundó en 1871, con el objeto de que fuera el núcleo de cultivo y adelantamiento del estudio de las ciencias de la naturaleza en nuestro país. Unido a este propósito, se dio primordial importancia a la publicación científica de los resultados de estos estudios y a la formación de colecciones de nuestra riqueza geológica, prehistórica, florística y faunística, publicando al efecto una revista que en ese momento se tituló Anales de la Sociedad Española de Historia Natural. El título de «Real» le fue conferido, a propuesta del Ministro de Instrucción Pública y Bellas Artes –Manuel Allende Salazar, por el rey Alfonso XIII, por Real Decreto de 3 de julio de 1903 (Gaceta de Madrid, 04-07-1903). Luego de la proclamación de la Segunda República y hasta el final de la guerra civil volvería a su primera denominación

The goal of this investigation was to assess the role of a number of environmental variables on the traits of a peracarid population inhabiting turfs of Ellisolandia elongata in a Mediterranean disturbed location. Samples were collected from a vertical and a horizontal surface to assess the role of orientation, and several structural traits of the turf (number of fronds, their height and width, available phytal area for colonization, and dry weight) were measured. The samples were characterized by their species composition, relative abundance of constant species, total abundance of individuals, and α-diversity (species richness, Shannon index and Pielou’s evenness). Generalized linear models were used to relate environmental variables with ecological descriptors, whereas a cluster plot and a principal correspondence analysis, both based on the Bray-Curtis coefficient, were conducted to detect the presence of distinct assemblages. Results showed orientation to be a key factor governing the assemblages, since samples from vertical and horizontal surfaces formed definite groups based on Bray-Curtis similarities. Moreover, GLMs pointed out that orientation influenced relative abundance of the majority of constant species, as well as species richness and Shannon index. Phytal height had a positive effect on the relative abundances of Hexapleomera bultidactyla, Coxischyrocerus inexpectatus and Hyale stebbingi, and a negative one on Shannon index and evenness, whereas available phytal area influenced positively evenness and negatively the relative abundance of Elasmopus pocillimanus. Thus, it can be inferred that although species composition depended on surface orientation, the spatial structure of the turf was the main driver for assemblage complexity, Partial fnancial support was received from the Spanish Ministry of Science and Innovation [Research Project “Polychaeta VI: Palpata-Canalipalpata I (CGL2014-53332-C5-3-P)”]

Antarctic and Southern Ocean environments are facing increasing pressure from multiple threats. The Antarctic Treaty System regularly looks to the Scientific Committee on Antarctic Research (SCAR) for the provision of independent and objective advice based on the best available science to support decision-making, policy development and effective environmental management. The recently approved SCAR Scientific Research Programme Ant-ICON - ‘Integrated Science to Inform Antarctic and Southern Ocean Conservation‘ - facilitates and coordinates high-quality transdisciplinary research to inform the conservation and management of Antarctica, the Southern Ocean and the sub-Antarctic in the context of current and future impacts. The work of Ant-ICON focuses on three research themes examining 1) the current state and future projections of Antarctic systems, species and functions, 2) human impacts and sustainability and 3) socio-ecological approaches to Antarctic and Southern Ocean conservation, and one synthesis theme that seeks to facilitate the provision of timely scientific advice to support effective Antarctic conservation. Research outputs will address the most pressing environmental challenges facing Antarctica and offer high-quality science to policy and advisory bodies including the Antarctic Treaty Consultative Meeting, the Committee for Environmental Protection and the Scientific Committee of the Commission for the Conservation of Antarctic Marine Living Resources.

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 29-04-2022, polyhomeotic (ph) es un miembro del Grupo Polycomb (PcG), un conjunto de genes implicados en silenciamiento epigenético que se requieren para mantener la expresión correcta de genes que confieren la identidad característica de los diversos tipos celulares de un organismo. Mutaciones en ph, así como en otros genes PcG, generan tumores tanto en Drosophila melanogaster como en humanos. En esta Tesis Doctoral hemos investigado el efecto tumorogénico de células con falta de función de ph (phKD) en distintas regiones del disco de ala de Drosophila. Hemos encontrado que los sobrecrecimientos se restringen a la región proximal del apéndice, probablemente debido a la función conjunta de las vías de señalización JNK y JAK/STAT en dicha zona. Por el contrario, la respuesta de la parte distal del apéndice y del notum es muy diferente, ya que sufren una disminución de tamaño. Hemos explorado más en detalle el comportamiento del notum y hemos visto que la falta de ph conduce a una acumulación moderada de las células en la fase G2 del ciclo celular, lo que podría contribuir a explicar dicha reducción de tamaño. Además, hemos descubierto que las células phKD son parcialmente refractarias a la apoptosis inducida por Rayos X. Proponemos que esto se debe a los bajos niveles de fosforilación de la histona H2Av, uno de los eventos iniciales implicados en la respuesta a daño en el ADN tras radiación ionizante. Finalmente, hemos analizado el comportamiento de clones phKD en relación al fenómeno de competición celular, un proceso homeostático responsable de la eliminación de células oncogénicas. En Drosophila, la regla general es que los clones de células tumorales (mutantes para scribble, lgl, Rab5, etc) son eliminados por competición celular, pero nuestros experimentos y otros descritos en la literatura indican que los clones phKD sobreviven y muchos incluso desarrollan sobrecrecimientos tumorales. No obstante, hemos mostrado que en realidad la competición celular sí opera en los clones phKD, ya que muchas células phKD de los bordes sufren estrés oxidativo, activan la vía JNK, las caspasas efectoras y mueren por apoptosis. A pesar de que la competición celular actúa sobre estos clones, en general no es suficiente para su eliminación. Sugerimos dos razones para explicar por qué muchos de estos clones son capaces de evadir el control de la competición celular: 1) las células phKD son parcialmente refractarias a la apoptosis y 2) la falta de ph altera de forma drástica la identidad de las células, de forma que los clones forman vesículas que se segregan del epitelio, minimizando el contacto con las células vecinas silvestres. Suponemos que esto dificulta las interacciones celulares necesarias para que la competición celular tenga lugar. Sorprendentemente, también hemos encontrado que, aunque la mayoría de las veces son las células phKD las que se eliminan por competición celular, a veces las células silvestres producen ROS, activan la vía JNK y mueren cuando están rodeadas de células phKD, lo que indica que dentro de un mismo tejido mosaico la competición celular puede operar en direcciones opuestas

The important paleontological and archaeological discoveries made in Tamajón in recent years have enriched the exceptional natural and cultural heritage of this town in the north of the Guadalajara province (central Spain). The extraordinary educational and outreach value of these findings led the PaleoIbérica Research Group to develop a project for the design and creation of the Paleontological and Archaeological Interpretation Centre of Tamajón (CIPAT, acronym in Spanish). In this new space, students and the general public have access to knowledge of the past of the region through three exhibition and didactic areas and the support of a rigorous and engaging infographic. The Paleontological Area allows visitors to explore, through fossils, replicas, models (real and virtual) and dioramas, the diversity of coastal and marine life that inhabited the region during the Late Cretaceous Age. Moreover, the area highlights crocodylomorphs, dinosaurs and fishes (identified through their fossilized tracks), and the remains of plants and invertebrates. The Archaeological Area shows the origin and uses of the building material known as Tamajón Stone by means of rough or carved samples, tools traditionally used in its extraction and carving, and historical photographs. Furthermore, in the Didactic Area, innovative specific educational activities are carried out, facilitating the knowledge and appreciation of the rich natural and cultural heritage of Tamajón. After its recent inauguration (August 2021), the CIPAT is a valuable tool to encourage the practice of positive attitudes toward geoconservation and to promote the sustainable and socioeconomic development of the region through geotourism. Research Projects and Contracts UI/BD/150971/2021 of the Foundation for Science and Technology (Portugal), and UCM.CT31/21 of the Complutense University of Madrid (Spain); and BOP-168 of the Provincial Council of Guadalajara, and 94/2018, 21/2019, 147/2021 of the University of Alcalá-Town Council of Tamajón (Spain). Aid for Rural Development 2021 of the Eurocaja Rural Foundation (Spain).

The general stress response (GSR) in Listeria monocytogenes plays a critical role in the survival of this pathogen in the host gastrointestinal tract. The GSR is regulated by the alternative sigma factor B (σB), whose role in protection against acid stress is well established. However, the mechanisms leading to its activation by low pH are unknown. Here, we investigated the involvement of the stressosome, a sensory organelle, in transducing low pH signals to induce the GSR. Mild acid shock (15 min at pH 5.0) activated σB and conferred protection against a subsequent lethal pH challenge. A mutant strain where the stressosome subunit RsbR1 was present but its remaining paralogues were genetically inactivated retained the ability to induce σB activity at pH 5.0. The role of stressosome phosphorylation in signal transduction was investigated by mutating the putative phosphorylation sites in the core stressosome proteins RsbR1 (rsbR1 T175A, T209A, T241A) and RsbS (rsbS S56A), or in the active site of the stressosome kinase RsbT (rsbT N49A). The rsbS S56A and rsbT N49A mutations abolished the response to low pH. The rsbR1 T175A variant, retained a near-wild type phenotype. The rsbR1 T209A and rsbR1 T241A mutants displayed constitutive σB activity. Mild acid shock upregulates invasion genes and stimulates epithelial cell invasion, effects that were abolished in mutants with an inactive or overactive stressosome. Overall, the results show that the stressosome is required for acid-induced activation of σB in L. monocytogenes. Furthermore, RsbR1 can function independently of its paralogues and that signal transduction requires RsbT-mediated phosphorylation of RsbS on S56 and RsbR1 on T209. These insights shed light on the mechanisms of signal transduction that activate the GSR in L. monocytogenes in response to acidic environments, and highlight the role this sensory process in the early stages of the infectious cycle.Author summaryThe stress sensing organelle known as the stressosome, found in many bacterial and archaeal lineages, plays a crucial role in both stress tolerance and virulence in the food-borne pathogen Listeria monocytogenes. However, the mechanisms that lead to its activation and the subsequent activation of the general stress response have remained elusive. In this study, we examined the signal transduction mechanisms that operate in the stressosome in response to acid stress. We found that only one of the five putative sensory proteins present in L. monocytogenes, RsbR1, was required for effective transduction of acid tress signals. We further found that phosphorylation of RsbS and RsbR1, mediated by the RsbT kinase, is essential for signal transduction. Failure to phosphorylate RsbS on Serine 56 completely abolished acid sensing by the stressosome, which prevented the development of adaptive acid tolerance. The acid-induced activation of internalin gene expression was also abolished in mutants with defective stressosome signalling, suggesting a role for the stressosome in the invasion of host cells. Together the data provide new insights into the mechanisms that activate the stressosome in response to acid stress and highlight the role this sensory organelle plays in virulence.

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de Lectura: 28-06-2022

Background and aims Mercury (Hg) is one of the most dangerous pollutant heavy metals to the environment, which causes several toxic effects in plants upon accumulation, such as induction of oxidative stress. Nitrogen (N) is one of the most limiting macronutrient for plants, being mostly assimilated as NO3─ which is reduced to NO2─ by the enzyme nitrate reductase (NR), prior its reduction to NH4+.Methods We studied the physiological alterations caused by Hg (0, 6 and 30 µM) in alfalfa plants grown at two different levels of NO3─: low, (2 mM; LN), and high (12 mM; HN) for one week using a semi-hydroponic culture system.Results Several parameters of oxidative stress such as lipid peroxidation, chlorophyll content, biothiol concentration and, ascorbate peroxidase (APX) and glutathione reductase (GR) activity showed that HN plants were less affected by Hg. Nitrate reductase activity and NO3─ concentration was altered under Hg stress, with lower impact in plants nourished with high NO3─. Conclusions Our results highlight the importance of the nitrogen nutritional status to improve tolerance to toxic metals like Hg.

Understanding the historical emergence and growth of long-range fisheries can provide fundamental insights into the timing of ecological impacts and the development of coastal communities during the last millennium. Whole-genome sequencing approaches can improve such understanding by determining the origin of archaeological fish specimens that may have been obtained from historic trade or distant water. Here, we used genome-wide data to individually infer the biological source of 37 ancient Atlantic cod specimens (ca 1050–1950 CE) from England and Spain. Our findings provide novel genetic evidence that eleventh- to twelfth-century specimens from London were predominantly obtained from nearby populations, while thirteenth- to fourteenth-century specimens were derived from distant sources. Our results further suggest that Icelandic cod was indeed exported to London earlier than previously reported. Our observations confirm the chronology and geography of the trans-Atlantic cod trade from Newfoundland to Spain starting by the early sixteenth century. Our findings demonstrate the utility of whole-genome sequencing and ancient DNA approaches to describe the globalization of marine fisheries and increase our understanding regarding the extent of the North Atlantic fish trade and long-range fisheries in medieval and early modern times. This work was supported by the Research Council of Norway project ‘Catching the Past’ (grant no. 262777), the Leverhulme Trust (grant nos. F/00 181/R and MRF-2013-065), the European Union's Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement No. 813383 (SeaChanges), the 4-OCEANS Synergy grant agreement no. 951649, the FISHARC-IF 658022 Marie-Curie-Sklodowska-IF fellowship for Career development and the European Molecular Biology Organization (ASTF 354-2016). The European Research Agency is not responsible for any use that may be made of the information this work contains. This research is also under the framework of the PID-118662GB-100 (FISHCIIS - Fishing Isotopes) project from the Spanish Ministry of Science and Innovation.