Fac.CV - Artículos de Revista
Examinar
Envíos recientes
Ítem Draft Genome Sequence of Pseudomonas syringae RAYR-BL, a Strain Isolated from Natural Accessions of Arabidopsis thaliana Plants(American Society for Microbiology, 2022-01) Fuenzalida-Valdivia, Isabel; Gangas, Maria Victoria; Zavala, Diego; Herrera-Vásquez, Ariel; Roux, Fabrice; Meneses, Claudio; Blanco-Herrera, FranciscaHere, we report the genome sequence of the P. syringae strain RAYR-BL, isolated from natural accessions of Arabidopsis plants. The draft genome sequence consists of 5.85 Mbp assembled in 110 contigs. The study of P. syringae RAYR-BL is a valuable tool to investigate molecular features of plant-pathogen interaction under environmental conditions. Copyright © 2022 Fuenzalida-Valdivia et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.Ítem Beyond purified dietary fibre supplements: Compositional variation between cell wall fibre from different plants influences human faecal microbiota activity and growth in vitro(John Wiley and Sons Inc, 2023-08) Solvang, Michael; Farquharson, Freda M.; Sanhueza, Dayan; Horgan, Graham; Russell, Wendy R.; Louis, PetraDietary fibre is a major energy source for the human gut microbiota, but it is unclear to what extent the fibre source and complexity affect microbial growth and metabolite production. Cell wall material and pectin were extracted from five different dicotyledon plant sources, apples, beet leaves, beetroots, carrots and kale, and compositional analysis revealed differences in the monosaccharide composition. Human faecal batch incubations were conducted with 14 different substrates, including the plant extracts, wheat bran and commercially available carbohydrates. Microbial activity was determined for up to 72 h by measuring gas and fermentation acid production, total bacteria (by qPCR) and microbial community composition by 16S rRNA amplicon sequencing. The more complex substrates gave rise to more microbiota variation compared with the pectins. The comparison of different plant organs showed that the leaves (beet leaf and kale) and roots (carrot and beetroot) did not give rise to similar bacterial communities. Rather, the compositional features of the plants, such as high arabinan levels in beet and high galactan levels in carrot, appear to be major predictors of bacterial enrichment on the substrates. Thus, in-depth knowledge on dietary fibre composition should aid the design of diets focused on optimizing the microbiota. © 2023 The Authors. Environmental Microbiology published by Applied Microbiology International and John Wiley & Sons Ltd.Ítem Molecular screening of selected vector-borne pathogens circulating in owned dogs in the Caribbean archipelago of Guadeloupe (France)(Veterinary Parasitology: Regional Studies and Reports, Volume 56, November 2024 Article number 101132, 2024-11) Imbert, Mélody; Muñoz-Hernández, Clara; Sánchez-Sánchez, Marta; Monteagudo, Luis V.; Fernández de Mera, Isabel G; Millán, JavierVector-borne diseases represent a major health challenge, both because of the complexity of their control, their common zoonotic nature, or the pathology they can cause in the individual. In tropical areas, surveillance of these diseases is even more important, since the activity of vectors is usually continuous throughout the year. To develop effective prophylaxis and surveillance programs, it is important to know the identity and prevalence of these pathogens as well as their distribution in a given territory. In Guadeloupe, a French archipelago located in the Lesser Antilles of the Caribbean, no information exists about vector-borne diseases in companion animals. With this aim, blood samples were obtained from 46 owned dogs with outdoor access from five different veterinary clinics located in the two mainland islands, and the presence of DNA of the main canine vector-borne pathogens (CVBP) was investigated through diverse PCR protocols. At least one pathogen was detected in 30.4 % of the dogs. The most frequently detected CVBP was Coxiella burnetii (17.4 %), followed by Dirofilaria immitis (8.7 %), and Candidatus Mycoplasma haematoparvum, Hepatozoon canis and Rickettsia spp. (2.2 % in all cases). One dog was coinfected with Candidatus M. haematoparvum and D. immitis. All samples were negative for Anaplasma spp., Ehrlichia spp., Bartonella spp., Borrelia burgdorferi sensu lato, piroplasmids, and Leishmania spp. No significant differences in pathogen occurrence were observed between the two main islands or according to the dog's sex and age groups. This study contributes to filling a relevant gap in the knowledge of vector-borne diseases in the Caribbean. © 2024 The AuthorsÍtem Detection of SARS-CoV-2 in Wastewater Associated with Scientific Stations in Antarctica and Possible Risk for Wildlife(Multidisciplinary Digital Publishing Institute (MDPI), 2024-04) González-Aravena, Marcelo; Galbán-Malagón, Cristóbal; Castro-Nallar, Eduardo; Barriga, Gonzalo P.; Neira, Víctor; Krüger, Lucas; Adell, Aiko D.; Olivares-Pacheco, JorgeBefore December 2020, Antarctica had remained free of COVID-19 cases. The main concern during the pandemic was the limited health facilities available at Antarctic stations to deal with the disease as well as the potential impact of SARS-CoV-2 on Antarctic wildlife through reverse zoonosis. In December 2020, 60 cases emerged in Chilean Antarctic stations, disrupting the summer campaign with ongoing isolation needs. The SARS-CoV-2 RNA was detected in the wastewater of several scientific stations. In Antarctica, treated wastewater is discharged directly into the seawater. No studies currently address the recovery of infectious virus particles from treated wastewater, but their presence raises the risk of infecting wildlife and initiating new replication cycles. This study highlights the initial virus detection in wastewater from Antarctic stations, identifying viral RNA via RT-qPCR targeting various genomic regions. The virus’s RNA was found in effluent from two wastewater plants at Maxwell Bay and O’Higgins Station on King George Island and the Antarctic Peninsula, respectively. This study explores the potential for the reverse zoonotic transmission of SARS-CoV-2 from humans to Antarctic wildlife due to the direct release of viral particles into seawater. The implications of such transmission underscore the need for continued vigilance and research.Ítem Antifungal susceptibility of Malassezia pachydermatis isolated from the external auditive conduct from dogs, in central Chile(Faculty of Veterinary Medicine, University of Tripoli, 2022) Núñez, Andrea H.; Hidalgo, Fabian G.; Morales, Pamela C.; Silva, Victor E.; Thomson, Pamela E.; Castro, Rodrigo A.Background: External otitis is common in dogs, and one of the main agents involved is Malassezia pachydermatis, a yeast belonging to the otic microbiota. Empirical treatment can fail; therefore, it is essential to know the antifungal susceptibility profile to prescribe appropriate treatment, a fact scarcely reported in Chile. Aim: This study aimed to determine the antifungal sensitivity of M. pachydermatis isolated from the external auditory canal of dogs in central Chile. Methods: Ear swabs from 30 dogs (15 healthy and 15 with external otitis) were used. Samples were subjected to cytology and fungal culture. The antifungal susceptibility was determined according to clinical and laboratory standards institute (CLSI) document M44A-2 using the disk diffusion test from amphotericin B, Caspofungin, fluconazole, nystatin, clotrimazole, and voriconazole were used. Results: The prevalence of M. pachydermatis was 66.7% from 8 healthy dogs and 12 with otitis. While fungal culture was not associated with the patient's clinical condition (p = 0.24), the yeast count by cytology was significantly higher in dogs with otitis (p = 0.003). The strains were sensitive to all antifungals except for Caspofungin, where 55% of the strains were resistant. Conclusion: Malassezia pachydermatis is isolated more frequently in dogs with otitis, and the ear cytological examination is useful to differentiate colonized dogs versus dogs with otitis. In addition, most antifungals in vitro are active against this yeast, except Caspofungin, an antifungal used in human medicine. This situation should be further monitored in epidemiological programs to evaluate the possible impact on Chilean public health. © 2022, Faculty of Veterinary Medicine, University of Tripoli. All rights reserved.Ítem How to perform an electrocardiogram in an awake pond slider turtle (Trachemys scripta): a comparative study of five noninvasive methodologies(American journal of veterinary research, Volume 85, Issue 111 November 2024, 2024-11) Hammond, Hillary K.; Sallaberry-Pincheira, Nicole; Santangelo, Stephen; Barnett, Brian G.; Divers, Stephen J.OBJECTIVE: To compare multiple noninvasive ECG methods in pond sliders based upon repeatability, ability to recognize standard waveforms, and measurability. METHODS: The study was performed from November 2023 through January 2024. Ten healthy adult pond turtles were enrolled in the study. ECG tracings were obtained using 4 previously reported and 1 novel ECG methodology, using adhesive patches applied to the prehumeral fossae and abdominal scutes. The 50 ECG tracings were blinded by method and turtle, randomized for evaluation by 4 observers, and assessed for quality on a scale from 0 to 3. RESULTS: Interobserver and intraobserver intraclass correlation coefficients for all tracings were 0.84 and 0.97, respectively, indicating an almost perfect agreement. The average score amongst the observers for each tracing was then averaged by method, ranging from 0.875 to 2.15. The novel method demonstrated a collective average of 2.15 and was the highest scoring method for 8 of 10 turtles. CONCLUSIONS: Electrocardiogram utilizing methods that apply adhesive patches to the prehumeral fossae and either the abdominal scutes of the plastron or prefemoral fossae in pond turtles can be performed to produce recognizable waveforms. CLINICAL RELEVANCE: Diagnostic tools, such as ECGs, are imperative to enhance veterinary care in nonconventional species, particularly with the rising trend of exotic pets worldwide.Ítem Identification and expression analysis of two steamer-like retrotransposons in the Chilean blue mussel (Mytilus chilensis)(Biological Research, Volume 57, Issue 1December 2024 Article number 17, 2024-12) Arriagada, Gloria; Quezada, Johan; Merino-Veliz, Nicolas; Avilés, Fernando; Tapia-Cammas, Diana; Gomez, Jorge; Curotto, Daniela; Valdes, Juan A.; Oyarzún, Pablo A.; Gallardo-Escárate, Cristian; Metzger, Michael J.; Alvarez, MarcoBackground: Disseminated neoplasia (DN) is a proliferative cell disorder of the circulatory system of bivalve mollusks. The disease is transmitted between individuals and can also be induced by external chemical agents such as bromodeoxyuridine. In Mya arenaria, we have cloned and characterized an LTR-retrotransposon named Steamer. Steamer mRNA levels and gene copy number correlates with DN and can be used as a marker of the disease. So far, the only mollusk where a retrotransposon expression relates to DN is Mya arenaria. On the other hand, it has been reported that the Chilean blue mussel Mytilus chilensis can also suffers DN. Our aim was to identify retrotransposons in Mytilus chilensis and to study their expression levels in the context of disseminated neoplasia. Results: Here we show that 7.1% of individuals collected in August 2018, from two farming areas, presents morphological characteristics described in DN. Using Steamer sequence to interrogate the transcriptome of M. chilensis we found two putative retrotransposons, named Steamer-like elements (MchSLEs). MchSLEs are present in the genome of M. chilensis and MchSLE1 is indeed an LTR-retrotransposon. Neither expression, nor copy number of the reported MchSLEs correlate with DN status but both are expressed at different levels among individual animals. We also report that in cultured M. chilensis haemocytes MchSLEs1 expression can be induced by bromodeoxyuridine. Conclusions: We conclude that SLEs present in Mytilus chilensis are differentially expressed among individuals and do not correlate with disseminated neoplasia. Treatment of haemocytes with a stressor like bromodeoxyuridine induces expression of MchSLE1 suggesting that in Mytilus chilensis environmental stressors can induce activation of LTR-retrotransposon. © The Author(s) 2024.Ítem Circular economy in Latin America and the Caribbean: Drivers, opportunities, barriers and strategies(Elsevier B.V., 2024-09) Gallego-Schmid, Alejandro; López-Eccher, Camila; Muñoz, Edmundo; Salvador, Rodrigo; Cano-Londoño, Natalia A.; Barros, Murillo Vetroni; Bernal, Daniel Choconta; Mendoza, Joan Manuel F.; Nadal, Ana; Guerrero, Ana BelénThis study assesses for the first time the drivers, opportunities, barriers, and strategies for the transition to a circular economy in Latin America and the Caribbean through a comprehensive systematic review of the current academic literature. A total of 247 articles have been analysed through the lens of the PESTLE framework (Political, Economic, Social, Technological, Legal, and Environmental), coupled with the consideration of the most recognised circular economy strategies (narrowing, slowing, closing, and regenerating) and solutions (the ten R's strategies: refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle, and recover). Key drivers identified in the literature include governmental policy shifts in the region towards circular and sustainable practices. These practices have focused on leveraging the abundance and diversity of natural resources and the region's climatic conditions that favour the development of bio-industries, renewable energies, and innovative sustainable materials, reflecting a clear adaptation of circular economy strategies to the specific needs and resources of Latin America and the Caribbean. Similarly, the technological and regulatory progress in pollution prevention and control, although still slow, has driven the implementation of circular economy strategies, making the role of new circular technologies fundamental for the region's sustainability. Barriers mentioned in the articles include limited governmental incentives, inadequate infrastructure for waste management, and the high costs associated with transitioning to circular economy practices, compounded by a lack of general public awareness and engagement. Regarding the circular economy strategies, the reviewed studies predominantly focus on recycling (“closing”) due to the immediate waste management needs of the region, with less emphasis on resource efficiency (“narrowing” and “slowing”) and minimal adoption of regenerative practices due to higher initial investment demands. Recycling and, to a lesser extent, recovery dominate the ten R's strategies discussed in the literature, indicating still a focus on end-of-life approaches in the region, while strategies like reduce, reuse, and repurpose are gaining representation; however, research on repair, refuse, remanufacture, and refurbishment should be the focus of future investigations. Finally, this article provides guidelines and recommendations for future research to facilitate the deployment and management of a sustainable circular economy in the regionÍtem Development of a cross-sectoral antimicrobial resistance capability assessment framework(BMJ Publishing Group, 2024-07) Ferdinand, Angeline S.; McEwan, Callum; Lin, Chantel; Betham, Kassandra; Kandan, Karishma; Tamolsaian, Gilam; Pugeva, Barry; McKenzie, Joanna; Browning, Glenn; Gilkerson, James; Coppo, Mauricio; James, RodneyAntimicrobial resistance (AMR) is an urgent and growing global health concern, and a clear understanding of existing capacities to address AMR, particularly in low-income and middle-income countries (LMICs), is needed to inform national priorities, investment targets and development activities. Across LMICs, there are limited data regarding existing mechanisms to address AMR, including national AMR policies, current infection prevention and antimicrobial prescribing practices, antimicrobial use in animals, and microbiological testing capacity for AMR. Despite the development of numerous individual tools designed to inform policy formulation and implementation or surveillance interventions to address AMR, there is an unmet need for easy-to-use instruments that together provide a detailed overview of AMR policy, practice and capacity. This paper describes the development of a framework comprising five assessment tools which provide a detailed assessment of country capacity to address AMR within both the human and animal health sectors. The framework is flexible to meet the needs of implementers, as tools can be used separately to assess the capacity of individual institutions or as a whole to align priority-setting and capacity-building with AMR National Action Plans (NAPs) or national policies. Development of the tools was conducted by a multidisciplinary team across three phases: (1) review of existing tools; (2) adaptation of existing tools; and (3) piloting, refinement and finalisation. The framework may be best used by projects which aim to build capacity and foster cross-sectoral collaborations towards the surveillance of AMR, and by LMICs wishing to conduct their own assessments to better understand capacity and capabilities to inform future investments or the implementation of NAPs for AMR.Ítem Identification of master regulator genes controlling pathogenic CD4+ T cell fate in inflammatory bowel disease through transcriptional network analysis(Scientific Reports, Volume 14, Issue 1 December 2024 Article number 10553, 2024-12) Jiménez, José M.; Contreras-Riquelme, J. Sebastián; Vidal, Pía M.; Prado, Carolina; Bastías, Macarena; Meneses, Claudio; Martín, Alberto J. M.; Perez-Acle, Tomás; Pacheco, RodrigoInflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including dysregulation of the immune response. Effector CD4+ T cells and regulatory CD4+ T cells (Treg) are central players in maintaining the balance between tolerance and inflammation. Interestingly, genetic modifications in these cells have been implicated in regulating the commitment of specific phenotypes and immune functions. However, the transcriptional program controlling the pathogenic behavior of T helper cells in IBD progression is still unknown. In this study, we aimed to find master transcription regulators controlling the pathogenic behavior of effector CD4+ T cells upon gut inflammation. To achieve this goal, we used an animal model of IBD induced by the transfer of naïve CD4+ T cells into recombination-activating gene 1 (Rag1) deficient mice, which are devoid of lymphocytes. As a control, a group of Rag1−/− mice received the transfer of the whole CD4+ T cells population, which includes both effector T cells and Treg. When gut inflammation progressed, we isolated CD4+ T cells from the colonic lamina propria and spleen tissue, and performed bulk RNA-seq. We identified differentially up- and down-regulated genes by comparing samples from both experimental groups. We found 532 differentially expressed genes (DEGs) in the colon and 30 DEGs in the spleen, mostly related to Th1 response, leukocyte migration, and response to cytokines in lamina propria T-cells. We integrated these data into Gene Regulatory Networks to identify Master Regulators, identifying four up-regulated master gene regulators (Lef1, Dnmt1, Mybl2, and Jup) and only one down-regulated master regulator (Foxo3). The altered expression of master regulators observed in the transcriptomic analysis was confirmed by qRT-PCR analysis and found an up-regulation of Lef1 and Mybl2, but without differences on Dnmt1, Jup, and Foxo3. These two master regulators have been involved in T cells function and cell cycle progression, respectively. We identified two master regulator genes associated with the pathogenic behavior of effector CD4+ T cells in an animal model of IBD. These findings provide two new potential molecular targets for treating IBD. © The Author(s) 2024.Ítem Genetic structure and diversity of the Chilean flat oyster Ostrea chilensis (Bivalvia: Ostreidae) along its natural distribution from natural beds subject to different fishing histories(Brazilian Journal of Genetics, 2022) Toro, Jorge E.; Oyarzún, Pablo A.; Toledo, Felipe E.; Navarro, Jorge M.; Illesca, Alex F.; Gardner, Jonathan P.A.Ostrea chilensis (Küster, 1844), the flat oyster, is native to Chile and New Zealand. In Chile, it occurs in a few natural beds, from the northern part of Chiloé Island (41 ºS) to the Guaitecas Archipelago (45 ºS). This bivalve is slow growing, broods its young, and has very limited dispersal potential. The Ostrea chilensis fishery has been over-exploited for a number of decades such that in some locations oysters no longer exist. The aim of this study was to study the genetic diversity of the Chilean flat oyster along its natural distribution to quantify the possible impact of the dredge fishery on wild populations. The genetic structure and diversity of Ostrea chilensis from six natural beds with different histories of fishing activity were estimated. Based on mitochondrial (Cytb) and nuclear (ITS1) DNA sequence variation, our results provide evidence that genetic diversity is different among populations with recent history of wild dredge fishery efforts. We discuss the possible causes of these results. Ultimately, such new information may be used to develop and apply new management measures to promote the sustainable use of this valuable marine resource. © Sociedade Brasileira de Genética.Ítem Global transcriptome profiles provide insights into muscle cell development and differentiation on microstructured marine biopolymer scaffolds for cultured meat production(Scientific Reports, Volume 14, Issue 1 December 2024 Article number 10931, 2024-12) Bezjak, Dragica; Orellana, Nicole; Valdivia, Guillermo; Acevedo, Cristian A.; Valdes, Jorge H.Biomaterial scaffolds play a pivotal role in the advancement of cultured meat technology, facilitating essential processes like cell attachment, growth, specialization, and alignment. Currently, there exists limited knowledge concerning the creation of consumable scaffolds tailored for cultured meat applications. This investigation aimed to produce edible scaffolds featuring both smooth and patterned surfaces, utilizing biomaterials such as salmon gelatin, alginate, agarose and glycerol, pertinent to cultured meat and adhering to food safety protocols. The primary objective of this research was to uncover variations in transcriptomes profiles between flat and microstructured edible scaffolds fabricated from marine-derived biopolymers, leveraging high-throughput sequencing techniques. Expression analysis revealed noteworthy disparities in transcriptome profiles when comparing the flat and microstructured scaffold configurations against a control condition. Employing gene functional enrichment analysis for the microstructured versus flat scaffold conditions yielded substantial enrichment ratios, highlighting pertinent gene modules linked to the development of skeletal muscle. Notable functional aspects included filament sliding, muscle contraction, and the organization of sarcomeres. By shedding light on these intricate processes, this study offers insights into the fundamental mechanisms underpinning the generation of muscle-specific cultured meat. © The Author(s) 2024.Ítem A global review of the American mink (Neovison vison) removal techniques – Patagonia as a case study for their potential application(Universidad de Concepcion, 2023-06) López, Ronar; Clapperton, B. Kay; Medina-Vogel, GonzaloAmerican mink (Neovison vison) represents a threat to both biodiversity and economy in various regions of the world, including Patagonia. This invasive species has been successfully removed from many areas of Europe. In Chile and Argentina there have been only patchily distributed attempts of local control to date and large-scale removal has been considered unfeasible. We analyzed available scientific information, to determine best-fit strategies and improved methodologies that increase efficiency (capture per unit of effort) in American mink control. We reviewed published papers about programs that aimed at local control, functional or total eradication of minks in the Web of Science (WoS) database. Based on accessible information, the influence of some field variables on capture efficiency was determined through a General Lineal Model. From 1525 results in the WoS search, 51 papers refer to mink control action carried out in 28 areas of Europe and South America since 1992. Trapping has been the most used and efficient capture method. Short trapping periods that cover larger lineal distances per control program, and the use of attractants, specifically pheromones, have led to improved control efficiency. Chilean, Scottish and English experiences showed among the highest trapping efficiency values. We identify areas of research needed on mink ecology and behavior and trapping techniques that could improve trapping efficiency. A control program that incorporates the outcomes of this data assessment has the potential to improve feral mink removal. But further research is required to ensure that these efficiency measures result in cost-effective control in Patagonia. © 2023 The author(s).Ítem Observation of the growth of a bifurcated tail in the Chilean Marked Gecko, Garthia gaudichaudii (Squamata, Phyllodactylidae)(Universidad de Concepcion, 2023-06) Reyes-Olivares, Claudio; Campos-Cifuentes, Fabián; Penna, MarioMany lizards (Superorder Lepidosauria) can regenerate their tail after fully or partially autotomizing it. However, abnormalities in regeneration can sometimes occur, such as the growth of one or more additional tails from wounds produced, for example, by incomplete autotomy. In this work, we describe the growth of an additional tail (i.e., bifurcated tail formation) in the endemic Chilean gecko, Garthia gaudichaudii, which reached a total length of 7.1 mm in 48 days of captivity. © 2023 The author(s). Gayana.Ítem Biosynthesis of photostable CdS quantum dots by UV-resistant psychrotolerant bacteria isolated from Union Glacier, Antarctica(Microbial Cell Factories, Volume 23, Issue 1 December 2024, Article number 140, 2024-12) Vargas-Reyes, Matías; Bruna, Nicolás; Ramos-Zúñiga, Javiera; Valenzuela-Ibaceta, Felipe; Rivas-Álvarez, Paula; Navarro, Claudio A.; Pérez-Donoso, José MBackground: Quantum Dots (QDs) are fluorescent nanoparticles with exceptional optical and optoelectronic properties, finding widespread utility in diverse industrial applications. Presently, chemically synthesized QDs are employed in solar cells, bioimaging, and various technological domains. However, many applications demand QDs with prolonged lifespans under conditions of high-energy radiation. Over the past decade, microbial biosynthesis of nanomaterials has emerged as a sustainable and cost-effective process. In this context, the utilization of extremophile microorganisms for synthesizing QDs with unique properties has recently been reported. Results: In this study, UV-resistant bacteria were isolated from one of the most extreme environments in Antarctica, Union Glacier at the Ellsworth Mountains. Bacterial isolates, identified through 16 S sequencing, belong to the genera Rhodococcus, Pseudarthrobacter, and Arthrobacter. Notably, Rhodococcus sp. (EXRC-4 A-4), Pseudarthrobacter sp. (RC-2-3), and Arthrobacter sp. (EH-1B-1) tolerate UV-C radiation doses ≥ 120 J/m². Isolated UV-resistant bacteria biosynthesized CdS QDs with fluorescence intensities 4 to 8 times higher than those biosynthesized by E. coli, a mesophilic organism tolerating low doses of UV radiation. Transmission electron microscopy (TEM) analysis determined QD sizes ranging from 6 to 23 nm, and Fourier-transform infrared (FTIR) analysis demonstrated the presence of biomolecules. QDs produced by UV-resistant Antarctic bacteria exhibit high photostability after exposure to UV-B radiation, particularly in comparison to those biosynthesized by E. coli. Interestingly, red fluorescence-emitting QDs biosynthesized by Rhodococcus sp. (EXRC-4 A-4) and Arthrobacter sp. (EH-1B-1) increased their fluorescence emission after irradiation. Analysis of methylene blue degradation after exposure to irradiated QDs biosynthesized by UV-resistant bacteria, indicates that the QDs transfer their electrons to O2 for the formation of reactive oxygen species (ROS) at different levels. Conclusions: UV-resistant Antarctic bacteria represent a novel alternative for the sustainable generation of nanostructures with increased radiation tolerance—two characteristics favoring their potential application in technologies requiring continuous exposure to high-energy radiation. Graphical abstract: (Figure presented.) © The Author(s) 2024.Ítem Deletion of VPS50 protein in mouse brain impairs synaptic function and behavior(BMC Biology,Volume 22, Issue 1 December 2024, Article number 142, 2024-12) Ahumada-Marchant, Constanza; Ancatén-Gonzalez, Carlos; Haensgen, Henny; Brauer, Bastian; Merino-Veliz, Nicolas; Droste, Rita; Arancibia, Felipe; Horvitz, H. Robert; Constantine-Paton, Martha; Arriagada, Gloria; Chávez, Andrés E.; Bustos, Fernando J.Background: The VPS50 protein functions in synaptic and dense core vesicle acidification, and perturbations of VPS50 function produce behavioral changes in Caenorhabditis elegans. Patients with mutations in VPS50 show severe developmental delay and intellectual disability, characteristics that have been associated with autism spectrum disorders (ASDs). The mechanisms that link VPS50 mutations to ASD are unknown. Results: To examine the role of VPS50 in mammalian brain function and behavior, we used the CRISPR/Cas9 system to generate knockouts of VPS50 in both cultured murine cortical neurons and living mice. In cultured neurons, KO of VPS50 did not affect the number of synaptic vesicles but did cause mislocalization of the V-ATPase V1 domain pump and impaired synaptic activity, likely as a consequence of defects in vesicle acidification and vesicle content. In mice, mosaic KO of VPS50 in the hippocampus altered synaptic transmission and plasticity and generated robust cognitive impairments. Conclusions: We propose that VPS50 functions as an accessory protein to aid the recruitment of the V-ATPase V1 domain to synaptic vesicles and in that way plays a crucial role in controlling synaptic vesicle acidification. Understanding the mechanisms controlling behaviors and synaptic function in ASD-associated mutations is pivotal for the development of targeted interventions, which may open new avenues for therapeutic strategies aimed at ASD and related conditions. © The Author(s) 2024.Ítem Transcription factor roles in the local adaptation to temperature in the Andean Spiny Toad Rhinella spinulosa(Scientific Reports, Volume 14, Issue 1 December 2024, Article number 15158, 2024-12) Hinostroza, Fernando; Araya-Duran, Ingrid; Piñeiro, Alejandro; Lobos, Isabel; Pastenes, LuisEnvironmental temperature strongly influences the adaptation dynamics of amphibians, whose limited regulation capabilities render them susceptible to thermal oscillations. A central element of the adaptive strategies is the transcription factors (TFs), which act as master regulators that orchestrate stress responses, enabling species to navigate the fluctuations of their environment skillfully. Our study delves into the intricate relationship between TF expression and thermal adaptation mechanisms in the Rhinella spinulosa populations. We sought to elucidate the dynamic modulations of TF expression in prometamorphic and metamorphic tadpoles that inhabit two thermally contrasting environments (Catarpe and El Tatio Geyser, Chile) and which were exposed to two thermal treatments (25 °C vs. 20 °C). Our findings unravel an intriguing dichotomy in response strategies between these populations. First, results evidence the expression of 1374 transcription factors. Regarding the temperature shift, the Catarpe tadpoles show a multifaceted approach by up-regulating crucial TFs, including fosB, atf7, and the androgen receptor. These dynamic regulatory responses likely underpin the population’s ability to navigate thermal fluctuations effectively. In stark contrast, the El Tatio tadpoles exhibit a more targeted response, primarily up-regulating foxc1. This differential expression suggests a distinct focus on specific TFs to mitigate the effects of temperature variations. Our study contributes to understanding the molecular mechanisms governing thermal adaptation responses and highlights the resilience and adaptability of amphibians in the face of ever-changing environmental conditions. © The Author(s) 2024.Ítem Changes in the gut microbiome and colic in horses: Are they causes or consequences?(Faculty of Veterinary Medicine, University of Tripoli, 2022) Lara, Felipe; Castro, Rodrigo; Thomson, PamelaThe gut microbiome is a compound for millions of microorganisms that coexist in an organized way and contribute to the fermentation of different types of indigestible fibers by the small intestine. Some techniques, such as the massive sequencing of the 16S ribosomal RNA gene, have made it possible to obtain information about the abundance and functionality of the microorganisms that compose the equine gut microbiome and the interaction with their environment. Recent studies have identified the change in the composition of the intestinal microbiome during and after a colic episode, although is not clear if it is a cause or a consequence. The objective of this review was to elucidate whether there is a direct relationship between the changes that occur in the gut microbiome and colic in the equine. A systematized search in Embase, Web of Science, and PubMed was realized. Although there is good evidence that horses with colic have a change in their gut microbiome, it is not fully understood whether these changes are causes or effects. It is necessary to delve into this topic, considering studying larger population sizes. In addition, it would be of great value to previously know the normal intestinal microbiome of a group of healthy horses, which in the future could develop an episode of colic, to compare the before and after in the same individual. © 2022, Faculty of Veterinary Medicine, University of Tripoli. All rights reserved.Ítem Asymptomatic herpes simplex virus brain infection elicits cellular senescence phenotypes in the central nervous system of mice suffering multiple sclerosis-like disease(Communications Biology, Volume 7, Issue 1 December 2024, Article number 81, 2024-12) Duarte, Luisa F.; Villalobos, Verónica; Farías, Mónica A.; Rangel-Ramírez, Ma. Andreina; González-Madrid, Enrique; Navarro, Areli J.; Carbone-Schellman, Javier; Domínguez, Angélica; Alvarez, Alejandra; Riedel, Claudia A.; Bueno, Susan M.; Kalergis, Alexis M.Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease affecting the central nervous system (CNS) in animals that parallels several clinical and molecular traits of multiple sclerosis in humans. Herpes simplex virus type 1 (HSV-1) infection mainly causes cold sores and eye diseases, yet eventually, it can also reach the CNS, leading to acute encephalitis. Notably, a significant proportion of healthy individuals are likely to have asymptomatic HSV-1 brain infection with chronic brain inflammation due to persistent latent infection in neurons. Because cellular senescence is suggested as a potential factor contributing to the development of various neurodegenerative disorders, including multiple sclerosis, and viral infections may induce a premature senescence state in the CNS, potentially increasing susceptibility to such disorders, here we examine the presence of senescence-related markers in the brains and spinal cords of mice with asymptomatic HSV-1 brain infection, EAE, and both conditions. Across all scenarios, we find a significant increases of senescence biomarkers in the CNS with some differences depending on the analyzed group. Notably, some senescence biomarkers are exclusively observed in mice with the combined conditions. These results indicate that asymptomatic HSV-1 brain infection and EAE associate with a significant expression of senescence biomarkers in the CNS. © The Author(s) 2024.Ítem Impact of KDM6B mosaic brain knockout on synaptic function and behavior(Scientific Reports, Volume 14, Issue 1 December 2024, Article number 20416, 2024-11) Brauer, Bastian; Ancatén-González, Carlos; Ahumada-Marchant, Constanza; Meza, Rodrigo C.; Merino-Veliz, Nicolas; Nardocci, Gino; Varela-Nallar, Lorena; Arriagada, Gloria; Chávez, Andrés E.; Bustos, Fernando J.Autism spectrum disorders (ASD) are complex neurodevelopmental conditions characterized by impairments in social communication, repetitive behaviors, and restricted interests. Epigenetic modifications serve as critical regulators of gene expression playing a crucial role in controlling brain function and behavior. Lysine (K)-specific demethylase 6B (KDM6B), a stress-inducible H3K27me3 demethylase, has emerged as one of the highest ASD risk genes, but the precise effects of KDM6B mutations on neuronal activity and behavioral function remain elusive. Here we show the impact of KDM6B mosaic brain knockout on the manifestation of different autistic-like phenotypes including repetitive behaviors, social interaction, and significant cognitive deficits. Moreover, KDM6B mosaic knockout display abnormalities in hippocampal excitatory synaptic transmission decreasing NMDA receptor mediated synaptic transmission and plasticity. Understanding the intricate interplay between epigenetic modifications and neuronal function may provide novel insights into the pathophysiology of ASD and potentially inform the development of targeted therapeutic interventions. © The Author(s) 2024.