Bioloxía Funcional

Permanent URI for this collectionhttps://hdl.handle.net/10347/34387

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Effects of climate on leaf phenolics, insect herbivory, and their relationship in pedunculate oak (Quercus robur) across its geographic range in Europe
(Springer, 2025-04-05) Valdés‑Correcher, Elena; Sobral Bernal, Mª Mar; Varela Río, Zulema; Castagneyrol, Bastien; Universidade de Santiago de Compostela. Departamento de Xeografía; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Centro Interdisciplinar de Investigación en Tecnoloxías Ambientais (CRETUS)
An increase in biotic interactions towards lower latitudes is one of the most consistent patterns in ecology. Higher temperatures and more stable climatic conditions at low latitudes are thought to enhance biotic interactions, accelerating biological evolution and leading to stronger anti-herbivore defences in plants. However, some studies report contradictory findings, highlighting the need for further investigation into the underlying mechanisms. We used a combination of field observations and feeding trials in controlled environments to investigate the effect of climate on chemical defences and insect herbivory in pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe, while controlling for physical defences. The concentration of lignin, flavonoids, and total phenolics increased significantly with temperature, whereas both field herbivory and weight of spongy moth (Lymantria dispar L.) larvae were negatively influenced by temperature. Lignin concentration positively influenced the weight of spongy moth larvae whereas it had no effect on field herbivory. We found no evidence of strong positive relationships between insect herbivory and larvae growth with leaf defences. Our study underscores the complexity of plant–herbivore interactions along climatic gradients and highlights the need for further research to disentangle these intricate relationships.
Trajectory analysis of hepatic stellate cell differentiation reveals metabolic regulation of cell commitment and fibrosis
(Nature Research, 2025-02-10) Martínez García de la Torre, Raquel A.; Ayuso García, Paula; Varela Rey, Marta María; Woodhoo, Ashwin; Sancho-Bru, Pau; Universidade de Santiago de Compostela. Centro de Investigación en Medicina Molecular e Enfermidades Crónicas (CiMUS); Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Departamento de Bioquímica e Bioloxía Molecular
Defining the trajectory of cells during differentiation and disease is key for uncovering the mechanisms driving cell fate and identity. However, trajectories of human cells remain largely unexplored due to the challenges of studying them with human samples. In this study, we investigate the proteome trajectory of iPSCs differentiation to hepatic stellate cells (diHSCs) and identify RORA as a key transcription factor governing the metabolic reprogramming of HSCs necessary for diHSCs’ commitment, identity, and activation. Using RORA deficient iPSCs and pharmacologic interventions, we show that RORA is required for early differentiation and prevents diHSCs activation by reducing the high energetic state of the cells. While RORA knockout mice have enhanced fibrosis, RORA agonists rescue multi-organ fibrosis in in vivo models. Notably, RORA expression correlates negatively with liver fibrosis and HSCs activation markers in patients with liver disease. This study reveals that RORA regulates cell metabolic plasticity, important for mesoderm differentiation, pericyte quiescence, and fibrosis, influencing cell commitment and disease.
Thriving Areas in Temperate Coastal Systems: Novel Insights for Marine Conservation
(Wiley, 2025-10-13) Sanabria Fernández, José A.; Baselga Fraga, Andrés; Lazzari, Natali; Gómez Rodríguez, Carola; Mouillot, David; Edgar, Graham; Dakos, Vasilis; Universidade de Santiago de Compostela. Departamento de Economía Aplicada; Universidade de Santiago de Compostela. Centro Interdisciplinar de Investigación en Tecnoloxías Ambientais (CRETUS); Universidade de Santiago de Compostela. Departamento de Zooloxía, Xenética e Antropoloxía Física; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
Aim Resilience is a crucial property of ecosystems experiencing accelerated degradation in natural environments. While the functional characteristics of ecosystems play a significant role in shaping their resilience, the development of functional approaches in marine conservation has been largely overlooked. In light of this deficiency, we simultaneously consider the functional richness and redundancy of marine fish communities associated with rocky reefs to uncover and characterise the thriving and struggling areas. Location Five marine ecoregions in southern Europe. Methods We collected data on the density of reef-associated marine fish species using the Reef Life Survey's standardised protocol. Based on these data, we estimated the functional richness and redundancy using four key functional traits: dietary patterns, gregariousness, position in the water column, and substrate preference. Next, we applied a predictive approach by using the XGBoost algorithm to estimate these functional metrics across the study area, including areas where in situ data were unavailable. Subsequently, to identify threshold points in the predictions, we employed decision trees, enabling us to unveil thriving and struggling areas. Results Our results indicate that the proportion of thriving areas (26.7%) is similar to that of struggling areas (26.5%), and that their distribution is heterogeneous across the ecoregions. We also find that these thriving areas are distinguished by lower values of human density, fishing pressure, chlorophyll concentrations, and they also exhibit a higher protection status compared to struggling areas. Main Conclusions In the current context of declining resilience, it is essential to address the functional dimension of biodiversity to unveil thriving and struggling areas, thereby highlighting the regions that require prioritisation in conservation and restoration efforts. Our findings offer critical information for policymakers and governments at local, regional, and national levels, pinpointing priority areas to enhance marine resilience and prevent the ongoing loss of this vital ecosystem property.
The lamprey habenula provides an extreme example for the temporal regulation of asymmetric development
(Frontiers Media, 2025) Guichard, Lucile; Rodicio Rodicio, María Celina; Barreiro Iglesias, Antón; Mazan, Sylvie; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Instituto de Investigación do Medio Acuático para Unha Saúde Global (iARCUS)
By their phylogenetic position and their marked epithalamic asymmetries, lampreys are relevant models for understanding the formation and evolution of this trait across vertebrates. In this study, we use a transcriptomic approach to identify novel signature markers to characterize the highly asymmetric, bipartite organization of habenulae in lampreys. Lamprey habenulae are subdivided into two complementary subdomains related, respectively, to the lateral/ventral and the medial/dorsal habenulae of jawed vertebrates: a dorsal, right-restricted subdomain and a bilateral subdomain that includes the left habenula as well as its ventral right counterpart. Analysis of the formation of the lamprey habenula at prolarval and larval stages using a combination of morphological, immunohistochemical, and in situ hybridization approaches highlights a marked asymmetric temporal regulation. The dorsal right subdomain forms and already expresses all identified signature markers in prolarval stages. In contrast, the left and ventral right subdomain appears significantly later, with the first indication of neuronal identity elaboration in these territories being observed in larval stages. As in gnathostomes, Wnt signaling may be involved in the regulation of this unique, asymmetric mode of development, since β-catenin shows asymmetric and highly dynamic nuclear distributions both in neural progenitors and differentiated neuronal precursors of the two habenular subdomains. These data confirm the importance of lampreys to unravel the developmental logic underlying the recurrence and variation of habenular asymmetries in vertebrates and pave the way for future functional analyses.
Environmental Impact of Choline Dihydrogenphosphate ([Chol][DHP]) on Seed Germination and Soil Microbial Activity
(MDPI, 2024-06-19) Cruz de la Fuente, Óscar; Reyes Ferreira, Otilia; Trasar Cepeda, María del Carmen; Sixto Anello, Teresa; Parajó Vieito, Juan José; Salgado Carballo, Josefa; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
The applicability of ionic liquids has grown exponentially over the last few decades. This growth is due to the easy modification of these compounds formed by ions, through the proper choice of both moieties, and the possibility of introducing functional groups into their cations and anions. However, studies of their toxicity and effects on the environment remain scarce. This study analyses firstly the response to adding different concentrations of choline dihydrogen phosphate to the germination of seeds of eight plant species. It also examines the microbial population and the respiration of two soils with contrasting organic matter contents. Seeds were incubated in a Petri dish in a Phytotron with a photoperiod of 16 h under light at 24 °C and 8 h in darkness at 16 °C. The activity of microbial populations of untreated and treated soils was analysed by isothermal microcalorimetry at 25 °C. Basal soil respiration kinetics were measured at optimal moisture (80% of field water retention capacity) and temperature (25 °C) over 10 days. The results indicate that this compound has diverse effects on the different endpoints. Nevertheless, this compound can be classified as non-toxic considering its effects on seeds and on soil, at least in the medium- to long-term
La herencia genética en un juego de cartas
(Graó, 2021-07) García Jartín, Lucía; Rodríguez Gacio, María del Carmen; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
Este trabajo ha sido realizado para comprobar si el juego de cartas “Mendelius” permite mejorar la adquisición por parte del alumnado de 4º de ESO de conocimientos sobre herencia genética, ya que este es uno de los temas que más dificultad entraña. Los resultados sugieren que el alumnado ha consolidado los conceptos básicos y superado algunas de las dificultades que se pretendían solventar con este juego.
Fungal diversity in Atlantic oak root systems: a pioneering study in the Cantabrian Mountains
(Springer Nature, 2026-01-24) Alas Gutiérrez, Norma; Fernández-Miranda Cagigal, Elena; Pérez-Girón, José Carlos; Viejo Somoano, Marcos; Cuesta, Candela; Ordás, Ricardo Javier; Álvarez-Álvarez, Pedro; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
Oak forests are native ecosystems that support diverse life forms and provide essential services. This study focused on elucidating the taxonomic characterization and diversity of fungal species in Atlantic oak woodlands dominated by Quercus petraea at its southwestern distribution limit in the Iberian Peninsula. Sampling was conducted in three protected natural areas to assess fungal root diversity by macroscopic and microscopic methods, including histological analysis of root sections. Additionally, metabarcoding techniques were used to sequence the internal transcribed spacer (ITS) region, targeting fungal diversity. The analysis identified 1,043 Amplicon Sequence Variants (ASVs), corresponding to 297 species. Although fungal richness was consistent across locations, community composition was geographically specific. Tree social classes also influenced fungal diversity, which was higher in the intermediate trees in some areas. Functional guilds varied markedly, with symbiotic fungi (notably ectomycorrhizal fungi and dark septate endophytes) most abundant based on sequencing reads, while saprotrophs were the most diverse genus. These findings highlight the structural and ecological complexity of oak-associated fungal communities and their potential importance in forest conservation and ecosystem functioning.
Aprendizaje mediante juego en la asignatura de Biotecnología Farmacéutica
(Educación Editora, 2020) Rodríguez Gacio, María del Carmen; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Membiela Iglesia, Pedro; Cebreiros Iglesias, María Isabel; Vidal López, Manuel
Este trabajo está basado en la utilización del juego para mejorar el aprendizaje de los contenidos teóricos de la asignatura de Biotecnología Farmacéutica en el Grado en Farmacia de la Universidad de Santiago de Compostela (USC). Esta herramienta educativa facilita tanto el aprendizaje activo de los conocimientos teóricos de la asignatura como la adquisición de ciertas competencias transversales
El uso del portafolio digital en las prácticas de Fisiología Vegetal
(Educación Editora, 2023) Rodríguez Gacio, María del Carmen; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Membiela, Pedro; Cebreiros, María Isabel
El portafolio digital se utilizó como herramienta de enseñanza-aprendizaje en la docencia práctica de la asignatura de Fisiología Vegetal. El alumnado valoró positivamente esta herramienta, ya que adquirió competencias transversales y consiguió un aprendizaje autónomo y responsable, participando activamente en su formación.
Aprendizaje basado en juegos de rol en la asignatura Fisiología Vegetal
(Educación Editora, 2024) Rodríguez Gacio, María del Carmen; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Membiela, Pedro; Cebreiros, Maria Isabel
Se utilizó el juego de rol para mejorar el aprendizaje de algunos de los contenidos teóricos de la asignatura Fisiología Vegetal (plantas transgénicas) del Grado en Ingeniería Agrícola y Agroalimentaria de la Universidad de Santiago de Compostela. Asimismo, se potenció el trabajo de algunas competencias transversales de este grado.
Delay of Germination-1 (DOG1): A Key to Understanding Seed Dormancy
(MDPI, 2020-04-09) Carrillo Barral, Néstor; Rodríguez Gacio, María del Carmen; Matilla Carro, Ángel Jesús; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
DELAY OF GERMINATION-1 (DOG1), is a master regulator of primary dormancy (PD) that acts in concert with ABA to delay germination. The ABA and DOG1 signaling pathways converge since DOG1 requires protein phosphatase 2C (PP2C) to control PD. DOG1 enhances ABA signaling through its binding to PP2C ABA HYPERSENSITIVE GERMINATION (AHG1/AHG3). DOG1 suppresses the AHG1 action to enhance ABA sensitivity and impose PD. To carry out this suppression, the formation of DOG1-heme complex is essential. The binding of DOG1-AHG1 to DOG1-Heme is an independent processes but essential for DOG1 function. The quantity of active DOG1 in mature and viable seeds is correlated with the extent of PD. Thus, dog1 mutant seeds, which have scarce endogenous ABA and high gibberellin (GAs) content, exhibit a non-dormancy phenotype. Despite being studied extensively in recent years, little is known about the molecular mechanism underlying the transcriptional regulation of DOG1. However, it is well-known that the physiological function of DOG1 is tightly regulated by a complex array of transformations that include alternative splicing, alternative polyadenylation, histone modifications, and a cis-acting antisense non-coding transcript (asDOG1). The DOG1 becomes modified (i.e., inactivated) during seed after-ripening (AR), and its levels in viable seeds do not correlate with germination potential. Interestingly, it was recently found that the transcription factor (TF) bZIP67 binds to the DOG1 promoter. This is required to activate DOG1 expression leading to enhanced seed dormancy. On the other hand, seed development under low-temperature conditions triggers DOG1 expression by increasing the expression and abundance of bZIP67. Together, current data indicate that DOG1 function is not strictly limited to PD process, but that it is also required for other facets of seed maturation, in part by also interfering with the ethylene signaling components. Otherwise, since DOG1 also affects other processes such us flowering and drought tolerance, the approaches to understanding its mechanism of action and control are, at this time, still inconclusive.
Testing a novel biotechnological passive sampler for monitoring atmospheric PAH pollution
(Elsevier, 2020-01-01) Aboal Viñas, Jesús; Concha-Graña, Estefanía; Nicola, F. de; Muniategui-Lorenzo, Soledad; López-Mahía, P. L.; Giordano, Simonetta; Capozzi, Fiore; Di Palma, Anna; Reski, Ralf; Zechmeister, Harald Gustav; Martínez-Abaigar, Javier; Fernández Escribano, José Ángel; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
In this study we evaluated a new type of passive air sampler, the “mossphere” device, filled with a Sphagnum palustre clone. For this purpose, we compared the atmospheric levels of polyaromatic hydrocarbons (PAHs) collected using this device and those collected in conventional bulk deposition and particulate matter (PM10) samplers. All three types of samplers were exposed at 10 sites affected by different levels of pollution and located in two different climate zones. The bulk deposition/ mossphere comparison yielded a greater number of significant regressions with higher coefficients of determination than the PM10/ mossphere comparison. No significant regressions were observed for 3-ring PAHs in either comparison. The mosspheres explain ca. 50% of the variability of the concentrations of 4-, 5- and 6-ring PAHs and total PAHs detected in PM10 and ca. 70% of the corresponding concentrations detected in the bulk deposition. The use of the Sphagnum clone enables standardization of the set-up, thus making the mossphere device a good sampling tool for monitoring 4-, 5- and 6-ring and total PAHs, especially those associated with bulk deposition. The findings indicate the potential usefulness of this innovative technology for mapping PAH levels.
Global decrease in heavy metal concentrations in brown algae in the last 90 years
(Elsevier, 2023-11-28) Aboal Viñas, Jesús; Pacín Salvador, María do Carme; García-Seoane, R.; Varela Río, Zulema; González, A.G.; Fernández Escribano, José Ángel; Universidade de Santiago de Compostela. Departamento de Bioloxía Celular e Ecoloxía; Universidade de Santiago de Compostela. Centro Interdisciplinar de Investigación en Tecnoloxías Ambientais (CRETUS)
In the current scenario of global change, heavy metal pollution is of major concern because of its associated toxic effects and the persistence of these pollutants in the environment. This study is the first to evaluate the changes in heavy metal concentrations worldwide in brown algae over the last 90 years (>15,700 data across the globe reported from 1933 to 2020). The study findings revealed significant decreases in the concentrations of Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb and Zn of around 60–84% (ca. 2% annual) in brown algae tissues. The decreases were consistent across the different families considered (Dictyotaceae, Fucaceae, Laminariaceae, Sargassaceae and Others), and began between 1970 and 1990. In addition, strong relationships between these trends and pH, SST and heat content were detected. Although the observed metal declines could be partially explained by these strong correlations, or by adaptions in the algae, other evidences suggest an actual reduction in metal concentrations in oceans because of the implementation of environmental policies. In any case, this study shows a reduction in metal concentrations in brown algae over the last 50 years, which is important in itself, as brown algae form the basis of many marine food webs and are therefore potential distributors of pollutants.
Cold-blooded vertebrates evolved organized germinal center–like structures
(American Association for the Advancement of Science, 2023-11-01) Shibasaki, Yasuhiri; Afanasyev, Sergei; Fernández Montero, Álvaro; Ding, Yang; Watanabe, Shota; Takizawa, Fumio; Lamas Fernández, Jesús; Fontenla Iglesias, Francisco; Leiro Vidal, José Manuel; Krasnov, Aleksei; Boudinot, Pierre; Sunyer, J. Oriol; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía; Universidade de Santiago de Compostela. Instituto de Acuicultura (IA)
Germinal centers (GCs) or analogous secondary lymphoid microstructures (SLMs) are thought to have evolved in endothermic species. However, living representatives of their ectothermic ancestors can mount potent secondary antibody responses upon infection or immunization, despite the apparent lack of SLMs in these cold-blooded vertebrates. How and where adaptive immune responses are induced in ectothermic species in the absence of GCs or analogous SLMs remain poorly understood. Here, we infected a teleost fish (trout) with the parasite Ichthyophthirius multifiliis (Ich) and identified the formation of large aggregates of highly proliferating IgM+ B cells and CD4+ T cells, contiguous to splenic melanomacrophage centers (MMCs). Most of these MMC-associated lymphoid aggregates (M-LAs) contained numerous antigen (Ag)–specific B cells. Analysis of the IgM heavy chain CDR3 repertoire of microdissected splenic M-LAs and non–M-LA areas revealed that the most frequent B cell clones induced after Ich infection were highly shared only within the M-LAs of infected animals. These M-LAs represented highly polyclonal SLMs in which Ag-specific B cell clonal expansion occurred. M-LA–associated B cells expressed high levels of activation-induced cytidine deaminase and underwent significant apoptosis, and somatic hypermutation of Igμ genes occurred prevalently in these cells. Our findings demonstrate that ectotherms evolved organized SLMs with GC-like roles. Moreover, our results also point to primordially conserved mechanisms by which M-LAs and mammalian polyclonal GCs develop and function.
Philasterides dicentrarchi
(5M Books, 2021) Lamas Fernández, Jesús; Leiro Vidal, José Manuel; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Sitjà-Bobadilla, Ariadna; Bron, James E.; Wiegertjes, Geert; Piazzon, M. Carla
In this book chapter, we describe the equipment and methodologies used to isolate and culture the fish parasite Philasterides dicentrarchi, as well as the freezing techniques employed to maintain the parasite for extended periods. We also outline the procedures for transmission, infection, and vaccine preparation.
Analysis of intra-thallus and temporal variability of trace elements and nitrogen in Fucus vesiculosus: Sampling protocol optimization for biomonitoring
(Elsevier, 2021-06-30) García Seoane, Rita; Fernández Escribano, José Ángel; Boquete Seoane, María Teresa; Aboal Viñas, Jesús; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
To advance the methodological standardization of the biomonitoring technique using macroalgae, we comprehensively characterized the intra-thallus and temporal patterns of variation in concentrations of a wide set of elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Zn, N) and δ15N signal in 6 consecutive Fucus vesiculosus apical dichotomous sections collected monthly over a four-year period (2015–2019) at 3 sites on the NW coast of Spain. The concentrations of Al, Co, Fe, Ni, Pb and Zn increased significantly from the youngest to the oldest dichotomies regardless of the sampling time and collection site; As, Cd, N and δ15N showed the opposite trend. Time series analysis revealed a significant and consistent seasonal variation of As, Cd, Co, Cu, Fe, Hg, Ni, Zn, N and δ15N concentrations, with maximum values in winter and minimum values in summer. We discussed the possible mechanisms driving these two sources of variation, and proposed an efficient and effective sampling strategy to minimize their impact in the results of biomonitoring studies, in which the part of the algal thallus selected for chemical analysis and the sampling frequency were carefully considered. This protocol will improve the conclusions and comparability of biomonitoring data from coastal environments.
Spontaneous regeneration of cholecystokinergic reticulospinal axons after a complete spinal cord injury in sea lampreys
(Elsevier, 2024) González Llera, Laura; Santos Durán, Gabriel Nicolás; Sobrido Cameán, Daniel; Núñez-González, Carmen; Pérez-Fernández, Juan; Barreiro Iglesias, Antón; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
In contrast to humans, lampreys spontaneously recover their swimming capacity after a complete spinal cord injury (SCI). This recovery process involves the regeneration of descending axons. Spontaneous axon regeneration in lampreys has been mainly studied in giant descending neurons. However, the regeneration of neurochemically distinct descending neuronal populations with small-caliber axons, as those found in mammals, has been less studied. Cholecystokinin (CCK) is a regulatory neuropeptide found in the brain and spinal cord that modulates several processes such as satiety, or locomotion. CCK shows high evolutionary conservation and is present in all vertebrate species. Work in lampreys has shown that all CCKergic spinal cord axons originate in a single neuronal population located in the caudal rhombencephalon. Here, we investigate the spontaneous regeneration of CCKergic descending axons in larval lampreys following a complete SCI. Using anti-CCK-8 immunofluorescence, confocal microscopy and lightning adaptive deconvolution, we demonstrate the partial regeneration of CCKergic axons (81% of the number of axonal profiles seen in controls) 10 weeks after the injury. Our data also revealed a preference for regeneration of CCKergic axons in lateral spinal cord regions. Regenerated CCKergic axons exhibit colocalization with synaptic vesicle marker SV2, indicative of functional synaptic connections. We also extracted swimming dynamics in injured animals by using DeepLabCut. Interestingly, the degree of CCKergic reinnervation correlated with improved swimming performance in injured animals, suggesting a potential role in locomotor recovery. These findings open avenues for further exploration into the role of specific neuropeptidergic systems in post-SCI spinal locomotor networks.
Full regeneration of descending corticotropin-releasing hormone axons after a complete spinal cord injury in lampreys
(Elsevier, 2022) González Llera, Laura; Sobrido Cameán, Daniel; Santos Durán, Gabriel Nicolás; Barreiro Iglesias, Antón; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional
Sea lampreys are a vertebrate model of interest for the study of spontaneous axon regeneration after spinal cord injury (SCI). Axon regeneration research in lampreys has focused on the study of giant descending neurons, but less so on neurochemically-distinct descending neuronal populations with small caliber axons. Corticotropin-releasing hormone (CRH) is a neuropeptide that regulates the stress response or locomotion. CRH is also a neuropeptide of interest in the SCI context because descending CRHergic projections from the Barrington’s nucleus control micturition behavior in mammals. Recent work from our group revealed that in sea lampreys the CRHergic innervation of the spinal cord is only of descending origin. Thus, the lack of intrinsic CRH spinal cord neurons provides the opportunity to analyze the regeneration of this descending system by using immunofluorescence methods. Here, we used an antibody against the sea lamprey mature CRH peptide, confocal microscopy, lightning adaptive deconvolution, and ImageJ to analyze the regenerative capacity of the descending CRH-immunoreactive (-ir) axons of larval sea lampreys after a complete SCI at the level of the fifth gill. At 10 weeks post-lesion, when behavioral analyses showed that injured animals had recovered normal appearing locomotion, our results revealed a full recovery of the number of CRH-ir profiles (axons) at the level of the sixth gill. Thus, the CRH descending axons of lampreys fully regenerate after a complete SCI. Our study provides a new model to study spontaneous and successful axonal regeneration in a specific neuronal type with small caliber axons by using simple immunohistochemical methods.
Interactions between the Parasite Philasterides dicentrarchi and the immune system of the Turbot Scophthalmus maximus. A transcriptomic analysis
(MDPI, 2020-10-15) Valle Cao, Alejandra; Leiro Vidal, José Manuel; Pereiro González, Patricia; Figueras Huerta, Antonio; Novoa García, Beatriz; Dirks, Ron P.H.; Lamas Fernández, Jesús; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía; Universidade de Santiago de Compostela. Instituto de Investigación do Medio Acuático para Unha Saúde Global (iARCUS)
Philasterides dicentrarchi is a free-living ciliate that causes high mortality in marine cultured fish, particularly flatfish, and in fish kept in aquaria. At present, there is still no clear picture of what makes this ciliate a fish pathogen and what makes fish resistant to this ciliate. In the present study, we used transcriptomic techniques to evaluate the interactions between P. dicentrarchi and turbot leucocytes during the early stages of infection. The findings enabled us to identify some parasite genes/proteins that may be involved in virulence and host resistance, some of which may be good candidates for inclusion in fish vaccines. Infected fish responded to infection by generating a very potent inflammatory response, indicating that the fish use all of the protective mechanisms available to prevent entry of the parasite. The findings also provide some valuable insight into how the acute inflammatory response occurs in fish
Molecular characterization and gene expression modulation of the alternative oxidase in a scuticociliate parasite by hypoxia and mitochondrial respiration inhibitors
(Nature, 2020-07-17) Folgueira López, Iría; Lamas Fernández, Jesús; Sueiro Benavides, Rosa Ana; Leiro Vidal, José Manuel; Universidade de Santiago de Compostela. Departamento de Bioloxía Funcional; Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía; Universidade de Santiago de Compostela. Instituto de Investigación do Medio Acuático para Unha Saúde Global (iARCUS)
Philasterides dicentrarchi is a marine benthic microaerophilic scuticociliate and an opportunistic endoparasite that can infect and cause high mortalities in cultured turbot (Scophthalmus maximus). In addition to a cytochrome pathway (CP), the ciliate can use a cyanide-insensitive respiratory pathway, which indicates the existence of an alternative oxidase (AOX) in the mitochondrion. Although AOX activity has been described in P. dicentrarchi, based on functional assay results, genetic evidence of the presence of AOX in the ciliate has not previously been reported. In this study, we conducted genomic and transcriptomic analysis of the ciliate and identified the AOX gene and its corresponding mRNA. The AOX gene (size 1,106 bp) contains four exons and three introns that generate an open reading frame of 915 bp and a protein with a predicted molecular weight of 35.6 kDa. The amino acid (aa) sequence of the AOX includes an import signal peptide targeting the mitochondria and the protein is associated with the inner membrane of the mitochondria. Bioinformatic analysis predicted that the peptide is a homodimeric glycoprotein, although monomeric forms may also appear under native conditions, with EXXH motifs associated with the diiron active centers. The aa sequences of the AOX of different P. dicentrarchi isolates are highly conserved and phylogenetically closely related to AOXs of other ciliate species, especially scuticociliates. AOX expression increased significantly during infection in the host and after the addition of CP inhibitors. This confirms the important physiological roles of AOX in respiration under conditions of low levels of O2 and in protecting against oxidative stress generated during infection in the host

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