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Publicación Acceso abierto Mapping the architecture of phosphate regulation in Malassezia pachydermatis: from computational blueprints to phenotypic signals(Universidad de los Andes, 2025-12-04) Duarte Sánchez, Víctor Manuel; Celis Ramírez, Adriana Marcela; Ceballos Garzón, Carlos Andrés; Zimmermann, Bárbara Hanna; Rodríguez Bocanegra, María Ximena; Facultad de Ciencias::Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (Cemop)Phosphate regulation in fungi is controlled by the PHO signaling pathway, in which the transcription factor Pho4 and associated regulators govern phosphate uptake, storage, and stress adaptation. While this pathway is established as a determinant of virulence in Candida albicans and Cryptococcus neoformans, its role in Malassezia spp., remains unexplored. Malassezia pachydermatis, a lipid-dependent basidiomycetous yeast of veterinary and human medical relevance, is frequently implicated in canine dermatitis and otitis as well as opportunistic bloodstream infections in humans. In this study, we employed an integrative approach to elucidate the phosphate regulatory framework of M. pachydermatis. Using Hidden Markov Models built from curated PHO protein families, we identified candidate orthologs sharing conserved domains, regulatory motifs, and phylogenetic clustering with PHO-like regulators. STRING-based interaction analyses further supported the functional connectivity of these candidates within a phosphate-responsive network. Experimentally, we evaluated acid phosphatase secretion under phosphate deprivation and growth dynamics under phosphate-limiting conditions, establishing phenotypic correlates of phosphate regulation. Collectively, our results suggest for the first time a set of putative PHO components in M. pachydermatis, highlighting shared structural and functional features with canonical PHO regulators, and providing a framework for future genetic interrogation of phosphate homeostasis and its contribution to pathogenicity.Publicación Acceso abierto Temperature variability and the evolution of life-history traits in tropical vertebrates(Universidad de los Andes, 2025-12-02) Navarro Salcedo, Paula Andrea; Cadena Ordónez, Carlos Daniel; Crawford, Andrew Jackson; Pincheira Donoso, Daniel; Facultad de Ciencias::Biología Evolutiva de VertebradosTemperature variability at different temporal scales may shape the evolution of life-history traits in differential ways, but its effects on fecundity, longevity and their trade-off remain unclear, particularly in tropical systems. I evaluated whether daily and seasonal temperature ranges are associated with patterns of fecundity and longevity across amphibians, reptiles (squamates) and birds, and whether potential trade-offs between these life-history traits differ among clades of tropical vertebrates. I compiled data on species brood size (fecundity) and, maximum longevity, and obtained estimates of daily and seasonal temperature range from high-resolution climate data (1983–2016) for each species. For each taxon I fitted Bayesian phylogenetic hierarchical mixed models to assess the unfluence of daily and seasonal temperature ranges on fecundity and longevity. In amphibians, increasing daily temperature range was associated with higher fecundity and lower longevity, whereas seasonal temperature range was positively associated with both fecundity and longevity. In reptiles, neither daily nor seasonal temperature range predicted fecundity or longevity. In birds, fecundity increased with seasonal temperature. Trade-offs between fecundity and longevity were not detected in any taxa. Additionally, although elevational gradients, correlate with patterns in daily and seasonal temperature, elevation was not related to variation in fecundity or longevity, or their trade-off. These results indicate that associations between temperature variability and life-history traits differ among taxa and temporal scales, and a consistent fecundity–longevity trade-off is not detectable at macroecological scales in the tropics, likely reflecting taxon-specific thermal sensitivity and differences in available resource dynamics. By integrating multiple vertebrate groups and temporal scales of temperature variability, this study advances our understanding of how climate variability influences tropical life histories, while providing context for the conditions under which classic life-history trade-offs may or may not emerge.Publicación Acceso abierto Behavioral and volatile profiles of orchid bees (Sub-genus Euglossa): Unveiling diversity and chemical ecology in an andean forests(Universidad de los Andes, 2025-12-03) Dorado Suárez, Juan Camilo; Molina Escobar, Jorge Alberto; Ramírez, Santiago; Riaño Pachon, Diego Mauricio; Benavides López, José Luis; Facultad de Ciencias::Centro de investigaciones en microbiología y parasitología tropicalBees are among the most diverse and ecologically significant groups of insects. Orchid bees (Euglossa spp.) are key pollinators in Neotropical forests whose males collect aromatic compounds to create complex perfumes used in courtship. However, little is known about the diversity and chemical ecology of Andean populations of orchid bees or how environmental factors influence their behavior. This study combined field and laboratory approaches to characterize the behavioral activity and perfume chemistry of Euglossa males from a sub Andean forests in La Vega, Cundinamarca (Colombia), and to test the effects of chronic CO₂ exposure on their locomotor and odor-guided behavior. 52 males were collected and identified into 20 morphotypes based on morphological diagnostic traits. Field observations showed that environmental temperature significantly affected activity, with bees spending less time resting at higher temperatures. In olfactometer assays, individuals exposed to elevated CO₂ (800 ppm) moved more slowly and traveled shorter distances than controls, indicating reduced locomotor performance, though no differences in odor preference were detected. Chemical analyses of hind-tibial extracts revealed 62 volatile compounds dominated by terpenoids and alcohols; eucalyptol was the most recurrent compound and benzyl alcohol the most abundant. Perfume quantity, complexity, and volatility showed high individual variability. These results provide the first description of tibial volatiles for Andean Euglossa species and evidence that chronic CO₂ exposure can alter locomotor behavior. Together, they highlight the remarkable diversity of sub-Andean orchid bees and the need for further studies on how environmental change influences their sensory ecology.Publicación Embargo Evaluación de bacterias aisladas de la rizosfera de yuca y sacha inchi como mitigadores de estrés salino en tomate(Universidad de los Andes, 2025-12-04) Oliveros Rojas, Jorge Alberto; Bernal Giraldo, Adriana Jimena; Rodríguez Bocanegra, María Ximena; Celis Ramírez, Adriana Marcela; Facultad de Ciencias::Interacciones Moleculares MicrobianasLa salinización de los suelos representa una de las principales limitantes para la productividad agrícola, afectando especialmente cultivos sensibles como el tomate (Solanum lycopersicum L.) y comprometiendo la seguridad alimentaria. El estrés salino induce alteraciones morfológicas, fisiológicas y bioquímicas en las plantas, reduciendo su crecimiento y rendimiento. Ante esta problemática, las bacterias promotoras del crecimiento vegetal (PGPR) se han propuesto como una alternativa sostenible para mitigar los efectos adversos de la salinidad en los cultivos. El presente estudio tuvo como objetivo evaluar el potencial de bacterias PGPR aisladas de la rizosfera de Manihot esculenta y Plukenetia volubilis para mitigar el estrés salino en plantas de S. lycopersicum bajo condiciones de invernadero. Inicialmente, se realizó un cribado in vitro para determinar la tolerancia de los aislamientos bacterianos a diferentes concentraciones de salinidad. Posteriormente, se evaluó el efecto de los aislamientos seleccionados sobre parámetros morfológicos, fisiológicos y sobre el contenido de pigmentos fotosintéticos antioxidantes en plantas sometidas a estrés salino. Los resultados permitieron identificar dos microorganismos con alto potencial como mitigadores del estrés salino, los cuales mostraron tolerancia a condiciones salinas y efectos positivos sobre el crecimiento en biomasa y en producción de pigmentos fotosintéticos antioxidantes de S. lycopersicum. Estos hallazgos respaldan el uso de PGPR como una estrategia biotecnológica sostenible para mejorar la tolerancia al estrés salino en sistemas agrícolas.Publicación Acceso abierto Desentrañando la historia evolutiva de los buitres del Nuevo Mundo (Aves: Cathartiformes) y sus afinidades filogenéticas con Teratornithidae bajo un enfoque de evidencia total(Universidad de los Andes, 2025-12-04) Ortiz Pabón, Luis Gonzalo; Link Ospina, Andrés; Pelegrin Ramírez, Jonathan; Cadena Ordónez, Carlos Daniel; Degrange, Federico JavierCathartiformes constituye un orden que incluye siete especies de aves neognatas carroñeras, distribuidas exclusivamente en el continente americano y el Caribe. Sin embargo, el registro fósil evidencia una notable diversidad, con 29 especies extintas descritas, de las cuales las dos más antiguas se registran en el Eoceno de Eurasia. Por su parte, Teratornithidae, una familia extinta, está conformada por aves de gran talla y su posición filogenética ha sido motivo de amplia discusión, aunque históricamente se ha propuesto una estrecha relación con los buitres del Nuevo Mundo. En este estudio se reevaluaron las afinidades filogenéticas entre las especies actuales y extintas de Cathartiformes y las especies de Teratornithidae mediante un enfoque de evidencia total, integrando datos osteomorfológicos para todas las especies, y datos moleculares para los grupos actuales. Se tuvieron en cuenta 208 caracteres osteomorfológicos y secuencias de siete marcadores moleculares, los cuales se combinaron en un análisis bayesiano. Los resultados respaldan la hipótesis que ubica a Teratornithidae como un grupo cercano a Cathartiformes. Asimismo, se respalda la hipótesis del origen del orden para el Paleógeno. En conjunto, los resultados aportan una nueva línea de evidencia sobre la historia evolutiva y las relaciones filogenéticas de los buitres del Nuevo Mundo y los teratornítidos. Además, contribuye a clarificar los patrones evolutivos de estas aves carroñeras desde el Eoceno hasta la actualidad.Publicación Acceso abierto Análisis de desequilibrio de transmisión de variantes comunes en el Trastorno del Espectro Autista en familias colombianas(Universidad de los Andes, 2025-12-03) Lozano Martínez, Angélica Lizeth; Lattig Matiz, María Claudia; Bloch Morel, Natasha Ivonne; Celis Ramírez, Adriana Marcela; Facultad de Ciencias::Servicios Integrales en Genética Humana (Sigen); Centro de investigaciones en genética humana CIGENEl Trastorno del Espectro Autista (TEA) es un trastorno del neurodesarrollo, el cual se caracteriza por su heterogeneidad a nivel clínico y genético. La arquitectura genética está compuesta tanto por variantes raras con alto impacto funcional como por variantes comunes de bajo efecto a lo largo de todo el genoma. Sin embargo, la mayoría de estudios genéticos se han realizado en poblaciones de origen europeo, lo que limita la comprensión del componente genético del TEA en poblaciones latinoamericanas con ancestría admixta. Por este motivo, el presente estudio tuvo como objetivo el análisis de las variantes comunes en el TEA en familias en trío de una cohorte colombiana, utilizando el Test de Desequilibrio de Transmisión (TDT). El estudio se realizó a partir de datos de SNP array, sometidos a control de calidad, filtrado, imputación genómica y aplicación del TDT, seguido de análisis de desequilibrio de ligamiento y anotación funcional regulatoria de las variantes sobretransmitidas. Se identificaron en total 11 variantes sugestivas (p≤1x10-5), presentes en los cromosomas 7, 12, 13 y 17. Las variantes presentes en los cromosomas 7 y 12 se hallaron cercanas a los genes THSD7A y CHST11 respectivamente, pero se consideraron outliers debido a su expresión en tejidos no neuronales. Por otra parte, las variantes ubicadas en los cromosomas 13 y 17 tuvieron mayor relevancia biológica al encontrarse en regiones regulatorias cerca a los genes DACH1 y RGS9. La evidencia funcional previa en estos genes sugiere expresión en ganglios basales del cerebro en vías dopaminérgicas y GABAérgicas importantes para procesos conductuales, alterados en la condición del TEA.Publicación Acceso abierto Why not look like an adult? A global comparative analysis of delayed plumage maturation in Passerine birds(Universidad de los Andes, 2026-01-28) Ríos Orjuela, Juan Camilo; Cadena Ordónez, Carlos Daniel; Molina Escobar, Jorge AlbertoDelayed plumage maturation (DPM), the retention of subadult plumage beyond the first potential breeding season, is widespread among birds, yet its evolutionary drivers remain poorly understood. We conducted a global comparative analysis across 1,175 passerine species to test whether ecological seasonality and social or sexual signaling predict interspecific variation in DPM. Using phylogenetically informed models and ancestral state reconstructions, we found that DPM has evolved repeatedly but has been more frequently lost than gained, indicating a highly labile evolutionary history. The degree of DPM increased significantly with sexual dichromatism, supporting the hypothesis that delayed acquisition of adult-like plumage functions as a signaling delay that mitigates social aggression and competitive costs during early life stages. Among environmental predictors, DPM was positively associated with latitude and climatic axes reflecting intense warm-season conditions, suggesting that ecological seasonality and thermal stress may favor delayed maturation by constraining breeding windows or amplifying the costs of ornament production. Conversely, vegetation productivity (NDVI) and proxies of social bonding or territoriality showed no detectable effects, possibly due to limited behavioral resolution. Together, these findings indicate that DPM likely arises and is maintained through the joint influence of environmental constraints and social signaling pressures, functioning as a flexible life-history strategy that balances survival and reproductive trade-offs under variable ecological regimes. Our results position DPM as an adaptive, dynamically regulated trait at the interface of sexual selection, development, and environmental seasonality, highlighting the need for integrative behavioral, hormonal, and genomic studies to unravel its underlying mechanisms.Publicación Acceso abierto Portrait of a semi-aquatic hunter: Implications of head morphology in Helicops pastazae for its fish searching and capture strategy(Universidad de los Andes, 2025-11-28) Garavito Mendoza, Lina María; Molina Escobar, Jorge Alberto; García Cobos, Daniela; Sasa Marín, Mahmood; Sánchez Muñoz, Juan Armando; Facultad de Ciencias::Cimpat. Centro de Investigaciones en Microbiología y Parasitologia TropicalStudies on aquatic snakes in Europe and North America have shown that, through hydrodynamic convergence, there is a relationship between head shape and foraging strategies to capture prey in the water. This suggests that certain morphological traits could predict predatory behavior. However, this link between morphology and behavior has not been explored in South American aquatic snakes. In this study, we evaluated whether the head of Helicops pastazae, a species inhabiting Andean-Amazonian rivers in Colombia, Ecuador, and Peru, can provide insights into its predatory habits. We measured the heads of 99 museum specimens (28 males and 71 females) and analyzed them using linear and geometric morphometrics within a comparative framework that included aquatic and semi-aquatic representatives of the family Natricidae. Additionally, we conducted behavioral trials with eight captive H. pastazae individuals to assess their predatory strategies in an aquatic environment. Morphological analyses indicate that the head of H. pastazae resembles that of snakes performing frontal strikes, in which the head moves quickly forward to capture prey. During behavioral trials, we only recorded attacks involving lateral head movements. We also observed the importance of prey contact, and documented an exploratory probing behavior with an open mouth that occurred exclusively in males. This study provides the first evaluation of the relationship between head morphology and predatory behavior in a South American freshwater snake. We emphasize that morphology alone cannot fully explain hunting dynamics, as behavioral plasticity and ecological context play decisive roles in the species’ functional ecology.Publicación Restringido Desarrollo de un bioinsumo basado en comunidades bacterianas promotoras de crecimiento vegetal(Universidad de los Andes, 2026-01-24) Racedo Pulido, Camilo; Bernal Giraldo, Adriana Jimena; Leidy, Chad; Salcedo Galán, Felipe; Facultad de Ciencias::Interacciones Moleculares MicrobianasEn este proyecto se logró la obtención exitosa de un consorcio microbiano sintético mediante procesos de selección in vitro y una posterior validación en planta. El consorcio está conformado por tres bacterias pertenecientes a géneros distintos, ampliamente reportados en la literatura como bacterias promotoras del crecimiento vegetal (PGPB) debido a sus capacidades bioquímicas. Asimismo, se evaluaron diferentes estrategias de formulación, entre las cuales la preservación en medio líquido y el uso de biochar demostraron ser alternativas efectivas para mantener la viabilidad bacteriana por al menos 30 días. Los ensayos en planta evidenciaron que la formulación con biochar favorece una mayor consistencia en los efectos benéficos observados, resaltando su potencial como una estrategia prometedora para la aplicación de consorcios microbianos en sistemas agrícolas.Publicación Acceso abierto Niche conservatism mediates the response of montane birds to global warming(Universidad de los Andes, 2025-12-03) Burbano Hernández, Jessica Paola; Cadena Ordónez, Carlos Daniel; Ocampo Peñuela, Natalia; Link Ospina, Andrés; Linck, EthanAnthropogenic climate change alters large-scale climatic parameters and poses a major threat to global biodiversity. In birds, this phenomenon has been associated with shifts in elevational distributions along montane gradients, often mediated by the degree of climatic niche conservatism. However, the extent to which thermal niche conservatism varies among avian lineages, and how it influences their responses to climate change, remains poorly understood. Here, we investigated the relationship between the degree of climatic niche conservatism and contemporary elevational shifts in montane birds across the globe. To estimate niche conservatism, we compiled georeferenced occurrence data for 7,162 montane bird species and derived their elevational distributions (minimum, maximum, mean, and range size). Two complementary metrics of niche conservatism were calculated: Pagel’s λ, as an indicator of phylogenetic signal, and evolutionary rates (σ²) for elevational traits. These measures were then contrasted with empirical estimates of altitudinal shifts reported for tropical and temperate montane birds using phylogenetic generalized least squares models. Our results revealed strong heterogeneity in the degree of niche conservatism across the avian phylogeny. In general, in temperate North American species, niche conservatism was negatively related to contemporary changes in mean elevation, whereas in tropical birds, conservatism was positively associated with shifts in upper elevational limits. These findings indicate that the degree of climatic niche conservatism is related to elevational responses to climate change in montane birds, particularly in tropical systems, and provides a framework for understanding how different avian lineages may cope with anthropogenic warming through shifting along elevational gradients.Publicación Acceso abierto Pre-existing antibodies to gene therapy AAV vectors in colombian healthy donors and patients with neurodegenerative diseases: implications for clinical translation(Universidad de los Andes, 2025-12-04) Sánchez Gutiérrez, Cristina; Valderrama Aguirre, Augusto Elias; Rincón Acelas, Melvin Yesid; Lattig Matiz, María Claudia; González Aseguinolaza, GloriaAdeno-associated virus (AAV) vectors are widely utilized in gene therapy due to their favorable safety profile, low immunogenicity, and organ-specific targeting capabilities. Pre-existing humoral immunity, particularly neutralizing antibodies (NAbs), can impede vector entry and therapeutic efficacy, while total antibodies (TAbs) or non-neutralizing antibodies may alter vector biodistribution. Seroepidemiological data from Latin America, particularly Colombia, remain scarce. This study aimed to (i) perform a global scoping review of TAb and NAb prevalence, (ii) assess TAbs against AAV2 and AAV9 in Colombian healthy donors and patients with neurological diseases, and (iii) conduct a pilot NAb analysis. The scoping review followed PRISMA guidelines, systematically identifying peer-reviewed studies reporting antibody prevalence against AAV across diverse populations. Concurrently, sera from defined Colombian cohorts were analyzed, with TAbs quantified via ELISA against AAV2 and AAV9, and NAbs evaluated using a transduction inhibition assay in a pilot study of healthy donors. Results showed high seroprevalence of anti-AAV2 antibodies across all groups, with lower prevalence for AAV9, although the neurological cohort exhibited elevated levels for both serotypes. Observed seroprevalence patterns align with international reports despite demographic and methodological differences. This study provides a comprehensive characterization of AAV immunity in Colombia, establishing a framework to guide future surveillance, support patient stratification, and inform the rational design of AAV-based therapeutic strategies in the region.Publicación Acceso abierto Análisis de la interacción proteína-proteína y el posible efecto de estabilización de MePATL3 por parte de XopAEXpm(Universidad de los Andes, 2026-01-15) Cortés Calderón, Santiago; Bernal Giraldo, Adriana Jimena; Zimmermann, Bárbara Hanna; Uribe Ardila, Jesus Alfredo; Díaz Tatis, Paula AlejandraLa yuca (Manihot esculenta Crantz) es un cultivo de gran importancia socioeconómica afectado por la bacteriosis vascular conocida como Cassava Bacterial Blight (CBB), causada por Xanthomonas phaseoli pv. manihotis (Xpm). Durante la infección, Xpm transloca efectores bacterianos mediante el sistema de secreción tipo III para interferir con los mecanismos de defensa de la planta. Entre estos efectores, XopAE ha sido asociado con la supresión de la inmunidad basal, aunque sus mecanismos moleculares no están completamente caracterizados. Estudios previos identificaron a MePATL3, una proteína de la familia PATELLIN asociada a membranas y tráfico vesicular, como un posible interactor de XopAE. En este trabajo se confirmó y caracterizó la interacción proteína–proteína entre XopAE^Xpm y MePATL3 utilizando sistemas heterólogos de expresión. La interacción física fue validada mediante ensayos de captura por afinidad (pull-down) acoplados a análisis por inmunoblot. Adicionalmente, se evaluó la interacción intracelular mediante complementación bimolecular de fluorescencia (BiFC) en Nicotiana benthamiana; sin embargo, no se detectó señal, lo que podría deberse a limitaciones técnicas del sistema o a la dependencia de microdominios de membrana. Finalmente, ensayos de abundancia proteica en líneas SALK1 de Arabidopsis thaliana complementadas con MePATL3 e infectadas con Pseudomonas fluorescens portadora de XopAE mostraron un aumento consistente de MePATL3 en presencia del efector, sugiriendo un posible efecto estabilizador. En conjunto, estos resultados aportan evidencia sobre el papel de XopAE en la manipulación de proteínas asociadas a la membrana durante la infección.Publicación Acceso abierto Procesos demográficos de plantas subandinas y la pendiente: un factor de estrés que impulsa el rebrote en bosques del Parque Nacional Cueva de los Guácharos, Huila, Colombia(Universidad de los Andes, 2025-12-01) Ramos Velásquez, Laura Isabel; Stevenson Díaz, Pablo Roberto; Prada Cordero, Cecilia Margarita; Dalling, James; Rada Rincon, Fermin Jose; Facultad de CienciasComprender la composición de las especies y la dinámica forestal es esencial para predecir la productividad de la biomasa e informar sobre la conservación en los ecosistemas montanos tropicales. Evaluamos los cambios florísticos, demográficos y de biomasa en dieciocho parcelas permanentes de 0,1 ha en bosques subandinos colombianos, incluyendo tanto bosques primarios (sin fuerte intervención antrópica conocida) como secundarios (de aproximadamente 60 años). Se realizaron dos censos de individuos (DBH ≥ 2,5 cm) durante un periodo de 7 a 13 años. Registramos 516 especies de 202 géneros y 89 familias. La composición florística difirió significativamente entre los tipos de bosque (PERMANOVA, p = 0,001), y los bosques de Roble negro (Trigonobalanus excelsa Lozano, Hern. Cam. & Henao) formaron conjuntos distintos. Las tasas demográficas fueron más altas en los bosques secundarios, con una mortalidad (4,17 % anual), un reclutamiento (4,51 % anual) y una tasa de crecimiento relativa (0,02 % anual) superiores a los de los bosques primarios. La acumulación media de biomasa aérea y la tasa de cambio anual fueron mayores en los bosques primarios (447,5 t ha−1 y 466,8 t ha−1 , respectivamente) que en los bosques secundarios (217,2 t ha−1 y 216,9 t ha−1, respectivamente). Cabe destacar que los bosques de roble negro mostraron la mayor acumulación de biomasa y la mayor tasa de cambio en biomasa. La producción neta anual de biomasa fue mayor en los bosques secundarios (8,72 t ha−1 año−1) que en los bosques primarios (5,66 t ha−1 año−1). Estos hallazgos ponen de relieve la singularidad ecológica y el potencial de recuperación de los bosques secundarios subandinos y subrayan el valor del monitoreo multitemporal para comprender la resiliencia de los bosques y evaluar su vulnerabilidad al cambio ambiental.Publicación Restringido Biotechnological production of pigments for the textile industry: E.coli MG1655/K12 as microbial platform to the production of red fluorescent protein using LB and alternative LB media under different induction conditions(Universidad de los Andes, 2025-12-03) Hernandez Caro, Diego Alexander; Velasco Mendoza, Josman Andrey; Danies Turano, Giovanna; Membrillo Hernández, Jorge; Vives Flórez, Martha JosefinaThe textile industry faces major environmental challenges associated with the use of synthetic dyes, which generate high levels of water pollution, elevated treatment costs, and health risks. This study evaluated the biotechnological production of red fluorescent protein (RFP) as an alternative pigment for textile applications using Escherichia coli MG1655/K12 as a microbial platform. RFP production was compared under standard conditions in Luria Bertani (LB) medium supplemented with antibiotic and IPTG and under alternative formulations that excluded antibiotics and IPTG and replaced tryptone with autoclaved baker’s yeast as a low-cost nitrogen source. The results showed that the removal of both antibiotic and IPTG did not significantly affect bacterial growth or RFP productivity, producing biomass, specific growth rates, and pigment levels comparable to standard conditions. Substitution of tryptone with autoclaved baker’s yeast maintained RFP production an increased biomass accumulation. Cost analysis showed a reduction of up to 17-fold in media cost compared to conventional LB. This work demonstrates the feasibility of a low-cost and environmentally sustainable microbial process for the production of a protein-based pigment with potential for industrial-scale textile applications.Publicación Acceso abierto Colonizing the Eastern Colombian Andes: Biogeographic reconstruction and speciation patterns of the genus Pristimantis(Universidad de los Andes, 2025-06-04) Tovar Ortiz, Angie Marcela; Crawford, Andrew Jackson; Rivera Correa, Mauricio; Madriñán Restrepo, Santiago; Padial, José Manuel; Facultad de Ciencias::BiomicsThe Northern Andes harbor one of the highest amphibian diversities worldwide, yet the evolutionary and biogeographic processes shaping this diversity remain insufficiently understood. We investigated the molecular phylogenetics, divergence times, and ancestral area reconstruction of Pristimantis (Craugastoridae) frogs across the Eastern Cordillera of Colombia. Using six gene fragments (12S, 16S, COI, CYTB, RAG1, TYR), we reconstructed a time-calibrated phylogeny for 273 species, representing 41.7% of the genus’ recognized diversity. Our results reveal that Pristimantis species of the Eastern Cordillera do not form a monophyletic group, but instead derive from at least six independent colonization events throughout the Neogene. These colonizations were followed by extensive in situ diversification, tightly associated with phases of accelerated Andean uplift and subsequent climatic shifts. Patterns of divergence suggest that species diversification was shaped by a combination of allopatric isolation, flickering connectivity during Pleistocene climatic oscillations, and parapatric speciation along elevational gradients. Ancestral state reconstructions further indicate that both niche conservatism and ecological divergence contributed to the elevational structure observed across clades. These findings highlight the Eastern Cordillera as a dynamic evolutionary mosaic where geological, climatic, and ecological forces have jointly promoted diversification, offering new insights into the processes driving speciation in tropical montane frogs.Publicación Restringido Recovering the health of Amazonian soils in Colombia: Evaluation of the effectiveness of a biofertilizer on the growth of Sacha Inchi (Plukenetia volubilis) seedlings and the soil microbial community in the producing areas of Caquetá(Universidad de los Andes, 2025-06-04) Mendoza Beltrán, Mariana; Mideros Bastidas, María Fernanda; Bernal Giraldo, Adriana Jimena; Cárdenas Toquica, Martha Emiliana; Pulecio, Cesar Augusto; Villegas Torres, Maria FranciscaIn Florencia, Caquetá, livestock and agricultural practices have significantly degraded Amazonian soils. As part of ongoing recovery efforts, farmers have begun using biofertilizers, although evidence supporting their effectiveness remains limited. This study evaluated a community-produced biofertilizer and its effects on the growth of Sacha Inchi (Plukenetia volubilis), a crop valued for its nutritional benefits and potential to strengthen sustainable food systems and agroforestry-based economies. A field trial was conducted in two soils with contrasting soil fertility perception to assess the biofertilizer’s impact on seedling growth, soil physicochemical properties, and beneficial cultivable microbial communities. Results showed that neither fertilization strategy, biofertilizer nor mineral fertilizer, significantly improved plant growth during the first 120 days, likely due to low nutrient demand at early stages. Both treatments increased the Soil Fertility Index, with mineral fertilization having a greater effect, although early signs of soil acidification and associated imbalances were observed under this treatment. No clear differences were detected in the abundance of nitrogen-fixing, phosphate-solubilizing, or potassium-solubilizing bacteria, suggesting limited short-term microbial responses. Elevated boron levels in the biofertilizer may have contributed to slight reductions in specific microbial groups, particularly in sandy soils. The promising effect of the biofertilizer on soil fertility index, along with the need for long-term evaluation and optimization to avoid affect micorbial communities underscores the importance of collaboration between scientists and local communities to advance sustainable agriculture.Publicación Acceso abierto Un pez eléctrico débil que no descansa: Novelty response durante el reposo del pez habitante de la arena Gymnorhamphichthys rondoni en Leticia-Amazonas(Universidad de los Andes, 2025-06-04) Realpe Sanabria, Pablo Emilio; Molina Escobar, Jorge Alberto; Benavides López, José Luis; Gutiérrez Cortés, Ángela Liliana; Facultad de Ciencias::Cimpat. Centro de Investigaciones en Microbiología y Parasitologia TropicalEl pez eléctrico débil Gymnorhamphichthys rondoni (Gymnotiformes: Rhamphichthyidae) reposa de día enterrado en la arena de arroyos de tierra firme de la Amazonía, manteniendo sus pulsos de descargas del órgano eléctrico (DOEs) a una tasa promedio de 15 Hz. Sin embargo, durante el reposo se pueden presentar incrementos abruptos en la frecuencia de descarga seguidos de una recuperación al nivel original y que en la literatura se conocen como Novelty response (Nr). Este estudio busca caracterizar los Nr en los patrones de DOEs de G. rondoni durante el reposo diurno bajo condiciones naturales en un arroyo amazónico (Yahuarcaca, Colombia). Para ello se analizaron grabaciones continuas de los DOEs obtenidos entre las 6:00 am y las 6:00 pm en varios individuos de G. rondoni por medio de la herramienta Rate Meter del software LabChart 8. Como resultados se encontraron 891 eventos de Nr correspondientes a grabaciones de 19 individuos registrados individualmente. De estos eventos de Nr el 84,85% (756/891) corresponden a eventos sencillos, el 14,81% (132/891) fueron eventos dobles y el 0,33% (3/891) a eventos triples. El análisis horario de la presencia de los eventos de Nr demuestra que no hay ninguna hora durante el periodo de reposo con un mayor número de ellos; pero si se observa que un mayor número de eventos de Nr se presentan en las horas posteriores al medio día. En promedio se presentan 4,24 eventos de Nr por hora durante el tiempo de reposo en G. rondoni. Además, en una muestra de 487 eventos de Nr se encontró una correlación significativa entre la amplitud en los eventos de Nr y la duración en el tiempo de recuperación del Nr al estado basal (R² = 0,61, p < 0,001). Tres posibles hipótesis sobre el papel de los eventos de Nr durante el reposo en individuos de G. rondoni se discuten.Publicación Acceso abierto Evaluación de respuesta de plantas de cacao (Theobroma cacao) del modelo araucano al estrés hídrico y a Lasiodiplodia theobromae(Universidad de los Andes, 2025-06-03) Villabona Gélvez, Alejandro; Zuluaga Cruz, Andrea Paola; Bernal Giraldo, Adriana JimenaEste estudio presenta el primer reporte confirmado de Lasiodiplodia theobromae como patógeno de Theobroma cacao en Colombia, evidenciado mediante aislamiento, identificación morfológica y molecular, y pruebas de patogenicidad. Se evaluó la incidencia de esta enfermedad en fincas de Arauca, Colombia, bajo diferentes sistemas de cultivo (agroforestales y libre exposición) y en cuatro genotipos de cacao del modelo araucano, encontrándose una significativa reducción de incidencia del patógno en sistemas agroforestales. Además, se analizó la influencia del estrés hídrico en la infección, utilizando la conductancia estomática y humedad en suelo como variables de referencia para el estrés, y se evaluó la expresión de genes PR mediante qPCR. Aunque no se encontró evidencia concluyente que vincule el estrés hídrico con un aumento en la susceptibilidad al patógeno, los resultados en campo refuerzan la importancia del manejo agroecológico en el control de enfermedades en cacao y sientan las bases para futuros estudios transcriptómicos enfocados en la interacción planta-patógeno bajo condiciones ambientales cambiantes en el marco del cambio climático.Publicación Acceso abierto High vocal diversity and absence of spatial structuring in the songs of Rufous-collared Sparrows (Zonotrichia capensis) within a tropical megacity(Universidad de los Andes, 2025-07-31) Sánchez González, Katherin; Cadena Ordónez, Carlos Daniel; Molina Escobar, Jorge Alberto; Derryberry, Elizabeth; Facultad de Ciencias::Biología Evolutiva de VertebradosUrbanization is one of the main drivers of global biodiversity loss, primarily through land-use changes associated with human activity. These changes may filter bird species based on their adaptability, as traits such as acoustic communication can be influenced by urban structure. In this context, the Acoustic Adaptation Hypothesis (AAH) proposes that the structure of the biophysical environment shapes the acoustic properties of signals to maximize their transmission. Consequently, altered conditions in urban settings (e.g., increased noise, reduced vegetation cover, and changes in microclimatic conditions) could promote variation in bird song. This study focused on elucidating how the characteristics of Bogotá—one of the most urbanized and noisiest cities in Latin America—might influence the song of the Rufous-collared Sparrow (Zonotrichia capensis), a common urban bird species. To this end, we recorded songs in the field and incorporated community science data to complement our sampling. Additionally, we collected information on noise levels, humidity, temperature, and the extent of built-up and vegetated areas, and related such variables to patterns of variation in song. Our results show high vocal diversity among individual repertoires, with divergence occurring at the individual level and no clear spatial pattern of variation across the city. Moreover, given the weak associations with the environmental factors analyzed and the proportion of unexplained variance in the models employed, we suggest that other, yet unidentified, mechanisms may play an important role in modulating the song of this species in Bogota.Publicación Acceso abierto Propagation of orchids native to the endangered seasonally dry tropical forest(Universidad de los Andes, 2025-06-04) Rueda Manrique, Camila; Madriñán Restrepo, Santiago; Arias, Tatiana; Rada Rincon, Fermin Jose; Downing, Jason; Facultad de Ciencias::Laboratorio de Botánica y SistemáticaThe Seasonally Dry Tropical Forest (SDTF) is one of the most endangered tropical ecosystems and contains an incredible diversity of endemic plant species. Orchids are a highly threatened plant family, with one in two species facing extinction threat. SDTF orchids are declining due to several threats, including climate change, poaching, and habitat loss. There is an urgent need for integrated conservation action to preserve and restore orchid diversity. Concerted efforts including IUCN Red List Assessments, ex-situ collections, in-vitro propagation, and species reintroductions are currently underway. The orchid species Encyclia cordigera and Cyrtopodium paniculatum are important for the Colombian Caribbean SDTF. In this study, they were assessed using IUCN Red List standards, their seeds underwent seed banking trials, and in-vitro protocols were enhanced by testing organic additives in the media for each species. To evaluate the effect of organic additives in the media, results were established by comparing biomass and recording plant growth stages over a six-month period. Regarding conservation status, both species are tentatively classified as Endangered under IUCN criteria B, due to the low value in Area of Occupancy and habitat loss and fragmentation. Seeds of E. cordigera and C. paniculatum did not show any significant difference while being stored at 4°C or -20C, but had a steady decline over the course of 6 months. Using organic additives was beneficial for the growth and development of E. cordigera, specially the combination of potato dextrose and coconut water. However, C. paniculatum preferred a media without any organic additives, with the control group having better results with plant biomass higher than other treatments. These results allowed us to create a protocol for SDTF orchid conservation practices, that has instructions on how to keep a record of seed pod collections and their seeds, check seed viability in storage, and has standardized in vitro seed germination procedures. The main outcome from this project is a guideline with feasible conservation actions replicable throughout different organizations in the Colombian Caribbean region.