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SNX5 promotes antigen presentation in B cells by dual regulation of actin and lysosomal dynamics
(Life Science Alliance, LLC, 0025-01) Cabrera-Reyes, Fernanda; Contreras-Palacios, Teemly; Jara-Wilde, Jorge; Caballero, Mia; Quiroga, Clara; Feijoo, Carmen G.; Díaz-Muñoz, Jheimmy; Yuseff, María-Isabel
B cells rapidly adapt their endocytic pathway to promote the uptake and processing of extracellular antigens recognized through the B-cell receptor (BCR). The mechanisms coupling changes in endomembrane trafficking to the capacity of B cells to screen for antigens within lymphoid tissues remain unaddressed. We investigated the role of SNX5, a member of the sorting nexin family, which interacts with endocytic membranes to regulate vesicular trafficking and macropinocytosis. Our results show that in steady state, B cells form SNX5-rich protrusions at the plasma membrane, which dissipate upon interaction with soluble antigens, whereas B cells activated with immobilized antigens accumulate SNX5 at the immune synapse where it regulates actin-dependent spreading responses. B cells silenced for SNX5 exhibit enlarged lysosomes, which are not recruited to the synaptic membrane, decreasing their capacity to extract immobilized antigens. Overall, our findings reveal that SNX5 is critical for actin-dependent plasma membrane remodeling in B cells in-volved in antigen screening and immune synapse formation, as well as endolysosomal trafficking required to promote antigen extraction and presentation. © 2024 Cabrera-Reyes et al.
Erratum to: Search for phenomena beyond the Standard Model in events with large b-jet multiplicity using the ATLAS detector at the LHC (The European Physical Journal C, (2021), 81, 1, (11), 10.1140/epjc/s10052-020-08730-0)
(European Physical Journal Volume 81, Issue 3 March 2021 Article number 249, 2021) Aad G.; Atlas Collaboration; Kuleshov S. gp; Department of Physics, Universidad Andres BelloThe institution
In the original HTML version of this article, one affiliation of the author V. O. Tikhomirov was missing. He is affiliated to the following two affiliations: P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia National Research Nuclear University MEPhI, Moscow, Russia The original article has been corrected. © 2021, CERN for the benefit of the ATLAS collaboration
Ongoing declines for the world’s amphibians in the face of emerging threats
(Nature Research, 2023-10) Luedtke, Jennifer A.; Chanson, Janice; Neam, Kelsey; Hobin, Louise; Maciel, Adriano O.; Catenazzi, Alessandro; Borzée, Amaël; Hamidy, Amir; Aowphol, Anchalee; Jean, Anderson; Sosa-Bartuano, Ángel; Fong G, Ansel; de Silva, Anslem; Fouquet, Antoine; Angulo, Ariadne; Kidov, Artem A.; Muñoz Saravia, Arturo; Diesmos, Arvin C.; Tominaga, Atsushi; Shrestha, Biraj; Gratwicke, Brian; Tjaturadi, Burhan; Martínez Rivera, Carlos C.; Vásquez Almazán, Carlos R.; Señaris, Celsa; Chandramouli S.R.; Strüssmann, Christine; Cortez Fernández, Claudia Fabiola; Azat, Claudio; Hoskin, Conrad J.; Hilton-Taylor, Craig; Whyte, Damion L.; Gower, David J.; Olson, Deanna H.; Cisneros-Heredia, Diego F.; Santana, Diego José; Nagombi, Elizah; Najafi-Majd, Elnaz; Quah, Evan S. H.; Bolaños, Federico; Xie, Feng; Brusquetti, Francisco; Álvarez, Francisco S.; Andreone, Franco; Glaw, Frank; Castañeda, Franklin Enrique; Kraus, Fred; Parra-Olea, Gabriela; Chaves, Gerardo; Medina-Rangel, Guido F.; González-Durán, Gustavo; Ortega-Andrade, H. Mauricio; Machado, Iberê F.; Das, Indraneil; Dias, Iuri Ribeiro; Urbina-Cardona, J. Nicolas; Crnobrnja-Isailović, Jelka; Yang, Jian-Huan; Jianping, Jiang; Wangyal, Jigme Tshelthrim; Rowley, Jodi J. L.; Measey, John; Vasudevan, Karthikeyan; Chan, Kin Onn; Gururaja, Kotambylu Vasudeva; Ovaska, Kristiina; Warr, Lauren C.; Canseco-Márquez, Luis; Toledo, Luís Felipe; Díaz, Luis M.; Khan, M. Monirul H.; Meegaskumbura, Madhava; Acevedo, Manuel E.; Napoli, Marcelo Felgueiras; Ponce, Marcos A.; Vaira, Marcos; Lampo, Margarita; Yánez-Muñoz, Mario H.; Scherz, Mark D.; Rödel, Mark-Oliver; Matsui, Masafumi; Fildor, Maxon; Kusrini, Mirza D.; Ahmed, Mohammad Firoz; Rais, Muhammad; Kouamé, N’Goran G.; García, Nieves; Gonwouo, Nono Legrand; Burrowes, Patricia A.; Imbun, Paul Y.; Wagner, Philipp; Kok, Philippe J. R.; Joglar, Rafael L.; Auguste, Renoir J.; Brandão, Reuber Albuquerque; Ibáñez, Roberto; von May, Rudolf; Hedges, S. Blair; Biju S.D.; Ganesh S.R.; Wren, Sally; Das, Sandeep; Flechas, Sandra V.; Ashpole, Sara L.; Robleto-Hernández, Silvia J.; Loader, Simon P.; Incháustegui, Sixto J.; Garg, Sonali; Phimmachak, Soumphthone; Richards, Stephen J.; Slimani, Tahar; Osborne-Naikatini, Tamara; Abreu-Jardim, Tatianne P. F.; Condez, Thais H.; De Carvalho, Thiago R.; Cutajar, Timothy P.; Pierson, Todd W.; Nguyen, Truong Q.; Kaya, Uğur; Yuan, Zhiyong; Long, Barney; Langhammer, Penny; Stuart, Simon N.
Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends. © 2023, The Author(s).
Comprehensive analysis of crystal structure, spectroscopic properties, quantum chemical insights, and molecular docking studies of two pyrazolopyridine compounds: potential anticancer agents
(Royal Society of Chemistry, 2023-11) Polo-Cuadrado, Efraín; López-Cuellar, Lorena; Acosta-Quiroga, Karen; Rojas-Peña, Cristian; Brito, Iván; Cisterna, Jonathan; Trilleras, Jorge; Alderete, Joel B.; Duarte, Yorley; Gutiérrez, Margarita
In this study, two pyrazolo[3,4-b]pyridine derivatives (4a and 4b) were grown using a slow evaporation solution growth technique and characterized by FT-IR, HRMS, 1H/13C NMR spectroscopy, and X-ray crystallography. The 4a and 4b structures crystallized in monoclinic and triclinic systems with space groups P21/n and P1̄, respectively. Theoretical calculations were performed at the DFT/B3LYP level for the optimized geometries. The results were in excellent agreement with the experimental data (spectroscopic and XRD). This investigation encompasses molecular modeling studies including Hirshfeld surface analysis, energy framework calculations, and frontier molecular orbital analysis. Intermolecular interactions within the crystal structures of the compounds were explored through Hirshfeld surface analysis, which revealed the notable presence of hydrogen bonding and hydrophobic interactions. This insight provides valuable information on the structural stability and potential solubility characteristics of these compounds. The research was extended to docking analysis with eight distinct kinases (BRAF, HER2, CSF1R, MEK2, PDGFRA, JAK, AKT1, and AKT2). The results of this analysis demonstrate that both 4a and 4b interact effectively with the kinase-binding sites through a combination of hydrophobic interactions and hydrogen bonding. Compound 4a had the best affinity for proteins; this is related to the fact that the compound is not rigid and has a small size, allowing it to sit well at any binding site. This study contributes to the advancement of kinase inhibitor research and offers potential avenues for the development of new therapeutic agents for cancer treatment. © 2023 The Royal Society of Chemistry.
A protocol for wide-scope non-target analysis of contaminants in small amounts of biota using bead beating tissuelyser extraction and LC-HRMS
(MethodsX, Volume 8 January 2021 Article number 101193, 2021) Gil-Solsona R.; Rodriguez-Mozaz S.; Diaz-Cruz M.S.; Sunyer-Caldú A.; Luarte T.; Höfer J.; Galbán-Malagón C.; Gago-Ferrero P.
This work describes a robust and powerful method for wide-scope target and non-target analysis of xenobiotics in biota samples based on bead beating tissuelyser extraction, solid phase extraction (SPE) clean-up and further detection by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). Unlike target methodologies, non-target methods usually aim at determining a wide range of still unknown substances with different physicochemical properties. Therefore, losses during the extraction process were minimised. Apart from that, the reduction of possible interferences showed to be necessary to expand the number of compounds that can be detected. This was achieved with an additional SPE clean-up step carried out with mixed-bed multi-layered cartridges. The method was validated with a set of 27 compounds covering a wide range of physicochemical properties, and further applied to the analysis of krill and fish samples. • The bead beating extraction was efficient for a wide range of organic pollutants in small quantities of biota samples. • Multi-layered solid phase extraction clean-up yield a wide xenobiotics coverage reducing matrix effects. • Method validation with 27 compounds led to a suitable method for non-target analysis of organic pollutants in biota. © 2020
High seroprevalence of feline morbilliviruses in free-roaming domestic cats in Chile
(Archives of Virology, Volume 166, Issue 1, Pages 281 - 285January 2021, 2021) Busch, Johannes; Sacristán, Irene; Cevidanes, Aitor; Millán, Javier; Vahlenkamp, Thomas W.; Napolitano, Constanza; Napolitano C.; Sieg, Michael
Feline morbillivirus infections have gained increased attention due to repeated reports of their association with urinary tract disease in cats. In the present study, 112 serum samples from free-roaming domestic cats in Chile were tested for antibodies against feline morbillivirus genotypes 1 and 2 (FeMV-1 and FeMV-2) using an indirect immunofluorescence assay. In total, 63% of the animals showed antibodies against one or both FeMV genotypes. Antibodies directed exclusively against FeMV-2 were significantly more prevalent in male cats. The correlation of sex and FeMV-2 infection might give insight into potential routes of transmission. We provide, for the first time, serological data on FeMV in Chile. © 2020, The Author(s).
Participation of two sRNA RyhB homologs from the fish pathogen Yersinia ruckeri in bacterial physiology
(Microbiological Research, Volume 242January 2021 Article number 126629, 2021) Acuña, Lillian G.; Barros, M. José; Montt, Fernanda; Peñaloza, Diego; Núñez, Paula; Valdés, Iván; Gil, Fernando; Fuentes, Juan A.; Calderón, Iván L.
Small noncoding RNAs (sRNAs) are important regulators of gene expression and physiology in bacteria. RyhB is an iron-responsive sRNA well characterized in Escherichia coli and conserved in other Enterobacteriaceae. In this study, we identified and characterized two RyhB homologs (named RyhB-1 and RyhB-2) in the fish pathogen Yersinia ruckeri. We found that, as in other Enterobacteriaceae, both RyhB-1 and RyhB-2 are induced under iron starvation, repressed by the Fur regulator, and depend on Hfq for stability. Despite these similarities in expression, the mutant strains of Y. ruckeri lacking RyhB-1 (ΔryhB-1) or RyhB-2 (ΔryhB-2) exhibited differential phenotypes. In comparison with the wild type, the ΔryhB-1 strain showed a hypermotile phenotype, reduced biofilm formation, increased replication rate, faster growth, and increased ATP levels in bacterial cultures. By contrast, in salmon cell cultures, the ΔryhB-1 strain exhibited an increased survival. On the other hand, the ΔryhB-2 strain was non-motile and showed augmented biofilm formation as compared to the wild type. The expression of a subset of RyhB conserved targets, selected from different bacterial species, was analyzed by quantitative RT-PCR in wild type, ΔryhB-1, ΔryhB-2, and ΔryhB-1 ΔryhB-2 strains cultured in iron-depleted media. RyhB-1 negatively affected the expression of most analyzed genes (sodB, acnA, sdhC, bfr, fliF, among others), whose functions are related to metabolism and motility, involving iron-containing proteins. Among the genes analyzed, only sdhC and bfr appeared as targets for RyhB-2. Taken together, these results indicate that Y. ruckeri RyhB homologs participate in the modulation of the bacterial physiology with non-redundant roles. © 2020 Elsevier GmbH
Effect of High-Intensity whole body vibration on blood lactate removal and heart rate after an all-out test in active young men
(Retos, Issue 39, Pages 471 - 4762021, 2021) Galaz-Campos, Daniel; Olivares-Arancibia, Jorge; Solis-Urra, Patricio; Suarez-Cadenas, Ernesto; Santos-Lozano, Alejandro; Rodríguez-Rodríguez, Fernando; Cristi-Montero, Carlos
Speed up recovery is fundamental in sport disciplines in which competitors must perform repeated trials within the same competition. The main objective of this study was to determine the effect of high-frequency whole body vibration (WBV) on blood [Lac] removal and heart rate (HR) after an all-out test. The participants performed a 4 x 100 m all-out test every 48 h in a random cross-over fashion, and a blood [Lac] removal protocol was applied after each test: a) 20 min seated (REST); b) squatting on a vibrating platform (S+V); and c) squatting on a non-vibrating platform (S-V). Blood [Lac] and HR were measured at rest, immediately after the 4 x 100 m all-out test (min 0), and at 10 and 20 min during the removal protocols. The results showed that the 3 protocols displayed significantly decreased blood [Lac] after 20 min (REST, S+V, and S-V removed Δ 6.6; Δ 10.5; and Δ 11.1 mmol•L-1, respectively). However, there were no significant differences in the blood [Lac] removal level between the S+V and S-V conditions. Interestingly, the S-V participants showed increased HR levels during the active recovery compared with the REST and S+V conditions. The effect of high-frequency WBV is not an additional stimulus to increase the blood [Lac] removal capacity in active young men, although WBV appeared to elicit less cardiovascular stress during recovery. © Copyright: Federación Española de Asociaciones de Docentes de Educación Física (FEADEF)
Effect of two training schedules with different distribution of intensity (polarized vs threshold) in the aerobic performance in trained cyclists
(Retos,Issue 39, Pages 686 - 690202, 2021) Rivera-Kofler, Tomas; Zavala-Crichton, Juan Pablo; Olivares-Arancibia, Jorge; Yáñez-Sepúlveda, Rodrigo c
Currently there are two most used training models that condition the work methodology in endurance athletes: Threshold Training (UMB) and polarized training (POL). The objective of the present study was to compare the effect of both programs on the aerobic performance of trained cyclists. The research included 18 athletes who were randomly distributed in the BMU group (n= 9; age 38 ± 7 years; height 171.8 ± 6.9 cm; body weight 74.10 ± 10.94) and the POL group (n= 9; age 31.4 ± 12.2 years; height 167.5 ± 6.7 cm; weight 63.88 ± 5.37) who completed 4 weeks of training. Both methodologies were executed under similar characteristics in terms of total training time (BMU; 1085 min / wk; POL; 1024 min/wk) but with different intensity distribution (BMU= 70% in zone 1; 30% in zone 2; 0% in zone 3; POL= 88% in zone 1; 0% in zone 2; 12% in zone 3). Body weight (kg) and functional threshold power (PUF) were measured before and after each programming. Only group with POL load reduced their body weight after the program (POL= -1.38%; p = 0.003). Also, group POL improved their PUF (5.48%; p= 0.012) and by default the watt values per kilogram of weight (V/kg) they were increased (7.17%; p= 0.015). Compared to UMB intensity distribution, 4 weeks of POL training improves aerobic performance in trained cyclists. © Federación Española de Asociaciones de Docentes de Educación Física (FEADEF).
Global transcriptome profiles provide insights into muscle cell development and differentiation on microstructured marine biopolymer scaffolds for cultured meat production
(Nature Research, 0024-12) 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.
Impact of KDM6B mosaic brain knockout on synaptic function and behavior
(10.1038/s41598-024-70728-5, 0024-12) 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.
A Deep Dive into the Trophic Ecology of Engraulis ringens: Assessing Diet Through Stomach Content and Stable Isotope Analysis
(Multidisciplinary Digital Publishing Institute (MDPI), 0024-12) Cárcamo, Carolina; Schultz, Eric T.; Leiva, Francisco; Saavedra, Alvaro; Klarian, Sebastian A.
Our study investigates the trophic ecology of the anchoveta (Engraulis ringens). The anchoveta plays a key role in the Greater Humboldt Ecosystem and is extensively exploited by countries from the south-eastern Pacific Ocean. For a comprehensive study of trophic ecology, we employed a combined approach that included stomach content analysis, stable isotope analysis, and scaled mass index of body condition. Our results showed that the multivariate composition of the diet varies significantly between life stage and fishing zones in Chile. Copepods and euphausiids emerged as the dominant prey found in the stomachs across all fisheries zones. Stable isotope analysis revealed significant differences among different zones. The scaled mass index values were higher in the northern zone compared to the southern zones, for both juveniles and adults. This research carries significant implications for fisheries management and conservation efforts, such as the development of targeted management strategies that address variations in the trophic structure of anchoveta across different life stages and fishing zones. © 2024 by the authors.
Unrolling the Systematics of a Southeastern Pacific Chiton
(Multidisciplinary Digital Publishing Institute (MDPI), 0024-12) Ibáñez, Christian M.; Sirenko, Boris
The species Chiton echinatus was first described by Barmes in 1824. Subsequently, it has been allocated to several widely distributed genera (e.g., Acanthopleura, Enoplochiton, Mesotomura) within the subfamily Acanthopleurinae. In order to resolve this species’ taxonomic uncertainty, specimens were collected throughout its entire distribution (i.e. from Peru and Chile) and subjected to a series of morphological and phylogenetic analyses. Scanning electron microscopy was used to improve this species’ morphological description, whereas publicly available sequences were used to infer its phylogenetic position. Morphological and phylogenetic analyses suggest that this species merits its own genus, endemic to the Southeastern Pacific. Of the aforementioned genera, Mesotomura appears to be the most appropriate designation. Therefore, it is proposed that the name Mesotomura echinata be restored, and the range of this species be extended to 39° S. © 2024 by the authors.
Funding the public systems for research and innovation in Latin-America: An essential tool to improve the prevention and healthcare
(Asociacion Colombiana de Infectologia, 2024) Correa, Maria Dolores; Delgado, Lucy Gabriela; Francia, Maria E.; Jokelainen, Pikka; Saavedra, Claudia; Rodriguez-Morales, Alfonso J.; Gonzalez, Angel; Alvarez, Carlos; Gomez-Marin, Jorge E.
La pandemia de la COVID-19 parecía haber dejado claro no sólo para los organismos gubernamentales, sino para la sociedad en su conjunto, la importancia de la ciencia1. Nuestra revista publicó varias editoriales explicando y fundamentando la necesidad de la autonomía sanitaria cuyo requisito principal es la existencia de un sistema científico sólido y establecido2–4. Un ejemplo claro fue la disponibilidad de vacunas para COVID-19, las cuales llegaron en tiempos di símiles por país y con retraso con respecto a los países que las desarrollaron; por supuesto, esas vacunas son producto de la ciencia de países que invierten significativamente en el sector5. No hubo ningún país en Latinoamérica que pudiera desarrollar una vacuna con mayor antelación, y los países que se beneficiaron primero fueron los países con mayor desarrollo científico5. Sin embargo, no fueron solo las vacunas pues también hubo dificultades importantes con reactivos de diagnóstico, respiradores y medicamentos6–8. Sin ninguna ambigüedad, esto demuestra nuestra incapacidad para resolver problemas críticos para la supervivencia de los habitantes de nuestros países.
Physiological Performance and Biosorption Capacity of Exiguobacterium sp. SH31 Isolated from Poly-Extreme Salar de Huasco in the Chilean Altiplano: A Study on Rare-Earth Element Tolerance
(Multidisciplinary Digital Publishing Institute (MDPI), 2024-01) Serrano, Genesis; Fortt, Jonathan; Castro-Severyn, Juan; Castillo, Rodrigo; Saavedra, Claudia; Krüger, Gabriel; Núñez, Claudia; Remonsellez, Francisco; Gallardo, Karem
Rare-earth elements (REEs) are crucial metals with limited global availability due to their indispensable role in various high-tech industries. As the demand for rare-earth elements continues to rise, there is a pressing need to develop sustainable methods for their recovery from secondary sources. Focusing on Exiguobacterium sp. SH31, this research investigates the impact of La, Eu, Gd, and Sm on its physiological performance and biosorption capacity. Tolerance was assessed at pHpzc from 7 to 8 with up to 1 mM rare-earth element concentrations. This study visualized the production of extracellular polymeric substances using Congo red assays and quantified them with ultraviolet–visible spectroscopy. Attenuated total reflectance Fourier transform infrared spectroscopy characterized the functional groups involved in metal interactions. The SH31 strain displayed significant rare-earth element tolerance, confirmed extracellular polymeric substance (EPS) production under all conditions, and increased production in the presence of Sm. Spectroscopy analysis revealed changes in wavelengths associated with OH and R-COO-, suggesting rare-earth element interactions. SH31 demonstrated efficient metal adsorption, with removal rates exceeding 75% at pHpzc 7 and over 95% at pHpzc 7.5 and 8. The calculated Qmax value for rare-earth element biosorption was approximately 23 mg/g, and Langmuir isotherm models effectively described metal sorption equilibria. Genomic exploration identified genes related to extracellular polymeric substance formation, providing insights into underlying mechanisms. This study presents the first evidence of efficient La, Eu, Gd, and Sm adsorption by SH31, emphasizing its potential significance in rare-earth element recovery. © 2023 by the authors.
Trends in the effects of kelp removal on kelp populations, herbivores, and understory algae
(Elsevier B.V., 2024-01) Carranza, Daniela M.; Stotz, Gisela C.; Vásquez, Julio A.; Stotz, Wolfgang B.
Kelp forests provide habitat and resources to diverse organisms and provide valuable ecosystem services. However, marine deforestation due to wild kelp harvesting, among other drivers, is being observed worldwide. Studies assessing kelp removal effects often focus on the effects on kelp populations, although deforestation also impacts the organisms that interact directly or indirectly with kelp, including herbivores and algal assemblages. Using a meta-analytical approach, we estimated the magnitude and direction of kelp removal effects on kelp, invertebrate herbivores, and understory algae. We also tested if responses varied among functional groups of understory algae and whether results were influenced by the subtidal or intertidal distribution of the removed kelp species and the time elapsed since kelp removal. We observed a substantial decrease in kelp abundance, remaining for up to 4 years following kelp removal, with a larger decrease in subtidal kelp but no recovery observed in intertidal kelp over time. Invertebrate herbivore abundance showed no significant change over time. Understory algae abundance responded positively, although this effect tended to slightly decline over time following subtidal kelp removal. Canopy-, turf-forming and foliose algae were the most benefited, which raises concern about their potential to outcompete kelp. The early succession patterns and cascading effects within kelp forests illustrated here highlight the need for long-term studies to elucidate the long-lasting effects of kelp fisheries, which are scarce at present. There is also a need to consider kelp forests’ role in providing habitat and resources to improve predictive frameworks allowing kelp forest conservation and sustainable fisheries. © 2024
Transcription factor NAC1 activates expression of peptidase-encoding AtCEPs in roots to limit root hair growth
(American Society of Plant Biologists, 2024) Rodríguez-García, Diana R.; Rondón Guerrero, Yossmayer del Carmen; Ferrero, Lucía; Rossi, Andrés Hugo; Miglietta, Esteban A.; Aptekmann, Ariel A.; Marzol, Eliana; Pacheco, Javier Martínez; Carignani, Mariana; Gabarain, Victoria Berdion; Lopez, Leonel E.; Dominguez, Gabriela Díaz; Borassi, Cecilia; Sánchez-Serrano, José Juan; Xu, Lin; Nadra, Alejandro D.; Rojo, Enrique; Ariel, Federico; Estevez, José M.
Plant genomes encode a unique group of papain-type Cysteine EndoPeptidases (CysEPs) containing a KDEL endoplasmic reticulum (ER) retention signal (KDEL-CysEPs or CEPs). CEPs process the cell-wall scaffolding EXTENSIN (EXT) proteins that regulate de novo cell-wall formation and cell expansion. Since CEPs cleave EXTs and EXT-related proteins, acting as cell-wall-weakening agents, they may play a role in cell elongation. The Arabidopsis (Arabidopsis thaliana) genome encodes 3 CEPs (AtCPE1-AtCEP3). Here, we report that the genes encoding these 3 Arabidopsis CEPs are highly expressed in root-hair (RH) cell files. Single mutants have no evident abnormal RH phenotype, but atcep1-3 atcep3-2 and atcep1-3 atcep2-2 double mutants have longer RHs than wild-type (Wt) plants, suggesting that expression of AtCEPs in root trichoblasts restrains polar elongation of the RH. We provide evidence that the transcription factor NAC1 (petunia NAM and Arabidopsis ATAF1, ATAF2, and CUC2) activates AtCEPs expression in roots to limit RH growth. Chromatin immunoprecipitation indicates that NAC1 binds to the promoter of AtCEP1, AtCEP2, and, to a lower extent, AtCEP3 and may directly regulate their expression. Inducible NAC1 overexpression increases AtCEP1 and AtCEP2 transcript levels in roots and leads to reduced RH growth while the loss of function nac1-2 mutation reduces AtCEP1-AtCEP3 gene expression and enhances RH growth. Likewise, expression of a dominant chimeric NAC1-SRDX repressor construct leads to increased RH length. Finally, we show that RH cell walls in the atcep1-3 atcep3-2 double mutant have reduced levels of EXT deposition, suggesting that the defects in RH elongation are linked to alterations in EXT processing and accumulation. Our results support the involvement of AtCEPs in controlling RH polar growth through EXT processing and insolubilization at the cell wall. © 2024 The Author(s).
Ecological variation in invasive brown trout (Salmo trutta) within a remote coastal river catchment in northern Patagonia complicates estimates of invasion impact
(John Wiley and Sons Inc, 2024-01) Bahamonde, Paulina Andrea; Chiang, Gustavo; Mancilla, Gabriela; Contador, Tamara; Quezada-Romegialli, Caudio; Munkittrick, Kelly Roland; Harrod, Chris
Salmonids were first introduced into the Chilean fresh waters in the 1880s, and c. 140 years later, they are ubiquitous across Chilean rivers, especially in the southern pristine fresh waters. This study examined the brown trout (Salmo trutta) and native taxa ecology in two adjacent but contrasting rivers of Chilean Patagonia. During spring 2016 and spring–fall 2017 we examined the variation in benthic macroinvertebrate and fish community composition and characterized fish size structure, stomach contents, and stable isotopes (δ13C and δ15N) to understand population structure, fish diet, and trophic interactions between S. trutta and native taxa. The native Galaxias maculatus (puye) dominated the fish community (74% of abundance). S. trutta was less abundant (16% of survey catch) but dominated the fish community (over 53%) in terms of biomass. S. trutta showed distinct diets (stomach content analysis) in the two rivers, and individuals from the larger river were notably more piscivorous, consuming native fish with a relatively small body size (<100-mm total length). Native fishes were isotopically distinct from S. trutta, which showed a wider isotopic niche in the smaller river, indicating that their trophic role was more variable than in the larger river (piscivorous). This study provides data from the unstudied pristine coastal rivers in Patagonia and reveals that interactions between native and introduced species can vary at very local spatial scales. © 2023 Fisheries Society of the British Isles.
Insights into molecular links and transcription networks integrating drought stress and nitrogen signaling
(John Wiley and Sons Inc, 2024-01) Cerda, Ariel; Alvarez, José M.
Drought and the availability of nitrate, the predominant source of nitrogen (N) in agriculture, are major factors limiting plant growth and crop productivity. The dissection of the transcriptional networks' components integrating droght stress and nitrate responses provides valuable insights into how plants effectively balance stress response with growth programs. Recent evidence in Arabidopsis thaliana indicates that transcription factors (TFs) involved in abscisic acid (ABA) signaling affect N metabolism and nitrate responses, and reciprocally, components of nitrate signaling might affect ABA and drought gene responses. Advances in understanding regulatory circuits of nitrate and drought crosstalk in plant tissues empower targeted genetic modifications to enhance plant development and stress resistance, critical traits for optimizing crop yield and promoting sustainable agriculture. © 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.
Th-1 cytotoxic cell-mediated response predominates in the tracheal mucosa following Mycoplasma synoviae infection of MS-H-vaccinated chickens
(Elsevier B.V., 2023-12) Omotainse, Oluwadamilola S.; Wawegama, Nadeeka K.; Kulappu Arachchige, Sathya N.; Coppo, Mauricio C; Vaz, Paola K.; Saliha, Uneeb; Bogeski, Mirjana; Noormohammadi, Amir H.; Stent, Andrew W.
Mycoplasma synoviae is a pathogen of poultry that causes upper respiratory tract disease. MS-H is a live attenuated temperature-sensitive vaccine that effectively control M. synoviae infection in chickens. However, the mechanisms underpinning protection have not been described previously. In this study, specific-pathogen-free chickens were vaccinated at 3 weeks of age with MS-H vaccine and challenged with field strain M. synoviae 94011/v-18d at 6 weeks of age. Tracheal mucosal inflammation was characterised by the assessment of thickness, histopathological lesions, cellular infiltrates and cytokine transcription. Tracheal lesion scores of unvaccinated-challenged (-V+C) birds were higher than that of vaccinated-challenged (+V+C) birds. +V+C birds displayed early upregulation of IL-4, consistent with a Th-2-skewed response, followed by a later increase in IFN-γ transcription, indicating transition to a Th-1-skewed response. -V+C birds displayed a concurrent early Th-2 and Th-17 response characterised by increase expression of IL-4 and IL-17A respectively, and late T regulatory response characterised by increased IL-10 transcription. +V+C chickens had more cytotoxic T cells (CD8+ T cells) at 7- and 21 days post-challenge (dpc), while -V+C chickens had higher numbers of infiltrating CD4+CD25+ at 7 and 21 dpc. Overall, these observations suggest that the immune response in +V+C chickens had an inflammation characterised by an early Th-2 skewed response followed closely by a Th-1 response and infiltration of cytotoxic T cells, while the response in -V+C chickens was an early Th-2/Th-17-skewed response closely followed by a T regulatory response. © 2023 The Authors

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