Departamento de Ciencias Biológicas

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https://hdl.handle.net/1992/52103
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    13000 años de historia de vegetación, ocupación humana y volcanes - análisis paleoecológico del sitio arqueológico Cuba, Valle Medio del Río Cauca, Colombia
    (Uniandes, 2015) Velásquez Franco, Susana; Montes Rodríguez, Camilo; Cooke, Richard; González Arango, Catalina
    "En este estudio se presenta el primer análisis multiproxy de una sección de sedimentos (175 cm) proveniente del sitio arqueológico Cuba (66PER001), que permite revisar la idea de estabilidad climática y ecológica para los bosques premontanos de la Cordillera Central de Colombia durante el Holoceno, y de esta manera enmarcar los procesos de poblamiento temprano y domesticación de plantas en el noroccidente de Suramérica..."
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    8 casos de litigios sobre propiedad intelectual de especies biológicas
    (Universidad de los Andes, 2004) Serna Jaramillo, Natalia; González Couture, Gustavo Alfonso
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    A behavioral polymorphism as an intermediate stage in the evolution of divergent forms - partial migration in New World Flycatchers (Aves, Tyrannidae)
    (Uniandes, 2015) Gómez Bahamón, Valentina; Pulido, Francisco; Cadena Ordónez, Carlos Daniel; Amézquita Torres, Adolfo
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    A comparison of display behavior between two divergent anolis carolinensis populations
    (Universidad de los Andes, 2004) Bloch Morel, Natasha; Irschick, Duncan J.
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    A computational approach for the prediction of relevant chemosensory proteins in a broad range of insect taxa
    (Universidad de los Andes, 2020) Montes Ortiz, Zaide Katherine; Molina Escobar, Jorge Alberto; Reyes Muñoz, Alejandro; Jiménez Avella, Diego Javier; Latorre Stivalis, José Manuel
    Olfactory receptors in insects are being employed as novel targets to develop strategies to control the damaging behaviors of crop pests and disease vectors. Traditional methodologies for their identification are laborious and time-consuming. Thus, identifying these receptors at the genomic level provides a broader overview to compare different species, use of available databases, and increasing the number of candidate proteins in non-model insects. Here, we propose an in-silico approach using a combination of the genomic and functionally characterized dataset available in public databases to predict chemosensory receptors relevant for insect ecology. Using Hidden Markov Models, we generated 103 potential models capable of detecting chemosensory receptors, including olfactory receptors, odorantbinding proteins, and gustatory receptors involved in the detection of volatile organic compounds with high accuracy and covering a broader range of insect taxa. Our database set of predicted chemosensory includes a total of 3,708 ORs, 2,014 OBPs, 781 GRs, and 3,193 IRs proteins that should be useful for future experiments
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    A diverse and specific Phytophthora infestans sensu lato population associated with Solanum betaceum in southern Colombia
    (Universidad de los Andes, 2011) Mideros Bastidas, María Fernanda; Restrepo Restrepo, Silvia
    New populations within the genus Phytophthora, associated with late blight have been reported in recent years. In South America, the presence of P. andina associated with native and exotic plants, among which is tree tomato (Solanum betaceum), have been described as the result of the complex process of evolution of these plant pathogens. In the present study nuclear, mitochondrial sequences and SSR markers were used to determine the genetic diversity and structure of Phytophthora samples collected from S.betaceum crops in the Nariño and Putumayo departments. In addition, detached leaf assays were used to test aggressiveness of the strains on several cultivars of the host. Our results showed a P. infestans sensu lato population characterized by a high genetic diversity with individuals showing different levels of ploidy and high clonality, supported by the presence of only the A1 mating type. Isolates showed a high specificity to the host with a wide range of aggressiveness that could not be related to the genetic variation found. Ancestral polymorphism, as a result of cultural conditions of the host and an ongoing hybridization process in the region were suggested as hypothesis to explain the variation found. Results of this study contribute to the understanding of the evolutionary mechanisms associated with P. infestans sensu lato innative hosts.
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    A glimpse into the future through color
    (Universidad de los Andes, 2020) Guevara Verjel, Michelle Karina; Lasso De Paulis, Eloísa; Garzón López, Carol Ximena
    Paramos are biodiversity hotspots responsible for several key ecosystem services. These tropical high-mountain ecosystems are being subject to different anthropogenic threats, which include climate change. Using Open Top Chambers (OTC) to increase temperature in situ we are simulating future warming in the paramo Matarredonda on the eastern range of the Andes. Additionally, through hyperspectral imaging (HSI) and the use of vegetation indexes, we evaluated the physiological status of two paramo species, E. argentea and E. grandiflora, and the effect of warming on these indexes. Our results indicate that the physiological status of both species is changing due to an increase in temperature, where plants have less chlorophyll content, water content and suggest lower nitrogen uptake, among other stress indicators. Our results indicate that HSI can be used in the conservation of paramo plants for rapid evaluations of their status
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    A novel bacterial-mediated method for the differentiation of Aedes spp. larvae in mixed-nursery assays and its application in the determination of vegetative Lysinibacillus sphaericus biocontrol efficiency in invasive vector eradication
    (Universidad de los Andes, 2020) Dániel Gómez, Mario Felipe; Dussán Garzón, Jenny
    The establishment of Aedes aegypti and the recent invasion of Aedes albopictus has put Colombia at risk, as it now harbours two arboviral vector species. Studies have shown the susceptibility of Aedes aegypti to the vegetative toxins produced by Lysinibacillus sphaericus. This study aims to determine the potential of two L. sphaericus strains in the control of both Aedes species present in Colombia, in both single and mixed species nurseries. Given the similarities between both species, there exists a need to differentiate them for the development of precise control strategies. Accordingly, mixed nurseries employed an mRFP-expressing Escherichia coli strain as a differentiator. Coloration-aided differentiation facilitated the analysis of mixed nursery treatments and provided deeper scrutiny into the variables at play. This showed an increase in the biocontrol efficiency, pointing to probable ecological variables. Bioassays involving Ae. albopictus showed a lower resistance to the one reported for Ae. aegypti in single-species nurseries. The study concludes that the use of E. coli strains expressing fluorescent proteins are useful tools to be employed in areas like public health entomology. Moreover, it was found that the use of L. sphaericus strains for biocontrol of vector mosquitoes is a viable alternative to chemical insecticides.
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    A small heat shock protein important in plant defense is targeted by the Xanthomonas axonopodis pv. manihotis HpaF Effector
    (Uniandes, 2017) Gómez de la Cruz, Diana Camila; Bernal Giraldo, Adriana Jimena; Restrepo Restrepo, Silvia; Zimmermann, Barbara Hanna; González Almario, Adriana
    Xanthomonas axonopochs pv. manihotis (Xam) is the causal agent of bacterial blight in cassava (Manihot esculenta) and, like many plant pathogens, relies on the secretion of type three effectors (T3E) to disrupt plant defense and favor disease development. HpaF is a core T3E conserved among several Xam strains from diverse origins and has a role as suppressor of plant defenses elicited by Pattern Triggered Immunity (PTI). A cassava protein that interacts with HpaF was previously identified in our laboratory using a yeast-two-hybrid screen against a cassava cDNA library. This interactor was named HpaF Interactor 1 (HF11) and corresponds to an HSP20-like chaperone. This protein was thought to be important in A. thaliana plant defense, as a mutant line for the HF11 gene ortholog has PTI impairments. However, the same could not be concluded for the protein in cassava due to the complexity in the generation of mutants for this plant. Here we confirmed and validated the interaction between HpaF and HF11 using protein co-immunoprecipitation. We also showed that the HF11 mutant from A. thaliana is complemented when transformed with HF11 from cassava, confirming the functional homology of these proteins. This is the first approach towards the characterization of a cassava protein interacting with a Xam T3E.
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    A socioecological resilience approach for evaluating management effectiveness of marine protected areas
    (Uniandes, 2009) López Angarita, Juliana; Sánchez M., Juan Armando
    Coral reefs worldwide need urgent conservation action because of their high level of degradation and susceptibility. This conservation priority is more urgent in the face of current global change events, which obscure the possibility for understanding the socio-ecological systems (SESs) complex dynamics, and limits the management effectiveness of Marine Protected Areas (MPAs). MPAs' ineffectiveness and lack of tools to unravel SESs' social and ecological relationships make necessary the implementation of a holistic approach that helps to determine current state and potential risk of these systems. In the present study we create an integrative model based on socioecological resilience in order to assess the management effectiveness of MPAs. By using indexes to estimate Resilience and Human-Intervention trough indicators relating to the social and ecological status of the system, we are able to detect specific conservation strategies and action plans to improve resilience, based on the particular conditions of the MPAs. The model is tested in two MPAs of the Southern Caribbean (Colombia) and it determined they are in a risk state of low resilience and high human intervention. We provide evidence that this model results an appropriate tool for decision-makers and reserve managers since it provides an insight for improving MPA's protection effectiveness, capitalizing opportunities to consolidate conservation goals and mitigating the vulnerability of coral reefs ecosystems and local communities.
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    A step in biosafety: Genetic circuit design for the sabotage of sporulation capacity in Bacillus subtilis progeny
    (Universidad de los Andes, 2024-01-31) Pachón Dotor, Sergio Andrés; Pedraza Leal, Juan Manuel; Bernal Giraldo, Adriana Jimena; 79782625; 52644215; Chica Pratesi, Claudia; Muñoz Camargo, Carolina; Facultad de Ciencias::Biofísica
    Bacillus subtilis, a Gram-positive bacterium capable of sporulation through the activation of the spo0A gene, exhibits resilience against adverse conditions. This characteristic positions it as a candidate for hosting designed genetic circuits (DGC) with diverse applications. However, biosafety challenges arise due to the potential limitations of sporulation on disposal processes, despite its advantages in transportation and storage. Ideally, a variant allowing a single sporulation event is essential. Thus, understanding the effect of spo0A elimination during spore maturation in B. subtilis is crucial for safe utilization. Consequently, an in silico genetic circuit inhibiting sporulation in B. subtilis was designed using CRISPR-Cas9 to knock out the spo0A gene, laying the groundwork for future refinement and optimization. The circuit comprises an activation module based on the Lac operon, native to Escherichia coli, regulated by the lactose analog TMG to express Cas9. Another module is induced by sigma-G, a late-stage spore maturation transcription factor in B. subtilis, to express sgRNA targeting spo0A within the forespore. Once the active complex forms, it cuts the spo0A gene. Studies were conducted in both deterministic and stochastic contexts, analyzing the genetic circuit's behavior with or without inducers at different times. Deterministic solutions indicate that the DGC behavior is TMG dose dependent with TMG concentrations of 250 µM and 1000 sigma-G molecules, the circuit successfully sabotages the spo0A gene within 30 minutes. However, assessing the DGC robustness when not induced revealed spo0A cuts in the absence of TMG and sigma-G. Approximately 60% of the B. subtilis population cuts spo0A even when this behavior is not induced. To address this, a basal expression control module with RNA complementary to sgRNA (cRNA) was implemented, reducing undesired spo0A cut rates to less than 10% of the B. subtilis population. Nevertheless, it was demonstrated that the addition of cRNA module had no significative impact in the spo0A knockout time distribution. This study addressed the need for a Bacillus subtilis variant to sporulate only once, favoring disposal processes through CRISPR-Cas9 circuit design proposing that spo0A sabotaging efficacy is TMG dose dependent. An important challenge related to undesired cut rates in the absence of inducers was identified and resolved through a basal expression control module. Additionally, stochastic simulations highlighted noise influence on circuit behavior, emphasizing the significance of considering stochastic aspects in genetic circuit design. Finally, this study provides a solid foundation for future improvement and optimization of genetic circuits controlling sporulation in B. subtilis, with potential applications in synthetic biology and biosafety.
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    A study of the IGS/ETS region in octocorals and black corals
    (Universidad de los Andes, 2008) Hernández Durán, Sonia Eleonora; Sánchez Muñoz, Juan Armando
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    A theoretical approach to understanding mate searching behavior in females
    (2014) Chaparro Pedraza, Perla Catalina; Cordovez Alvarez, Juan Manuel; Stevenson Díaz, Pablo Roberto; Wiegmann, Daniel
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    A weeping form of Libidibia punctata (Willd.) Britton, from the Caribbean seasonally (very) dry tropical forest of Colombia
    (Universidad de los Andes, 2022-07-28) Delvasto Cornejo, Mathias; Madriñán Restrepo, Santiago; CC. 79158767
    Field work and reforestation projects allowed to find differences in Libidibia punctata growth through individuals. Morphometry and comparative studies revealed there exist two forms of this species, the first one characterized by an early branch weeping architecture and the second as an erect form, which usually is less branched and can reach the forest canopy in less time. In order to stablish the differences several statistical methods and morphological comparisons are used. The names L. punctata forma suspensa and L. punctata forma punctata are suggested for a clear differentiation of the individuals.
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    ÅAdelantan las semillas su desarrollo con respecto a la maduración del fruto?
    (Universidad de los Andes, 2017) Cruz Tejada, Diana María; Stevenson Díaz, Pablo Roberto; 80410477; Madriñán Restrepo, Santiago; Silveira, Fernando
    "Muchas plantas atraen dispersores de semillas e indican la presencia de frutos maduros con cambios en la coloración. Si la madurez de las semillas es simultánea con los mensajes visuales para los frugívoros, una porción de las semillas puede ser removida antes de estar lista para la dispersión. En este estudio probamos la hipótesis de retardo en la señal visual, que implica que para lograr un mayor éxito reproductivo en la planta, el desarrollo de la semilla debe anteceder el de la señal visual del fruto y así, no se dispersen semillas inviables. Evaluamos esta hipótesis con 6 especies tropicales que presentan frutos con coloraciones discretas para estados inmaduro, intermedio y maduro, revisando la predicción que el desarrollo de las semillas de frutos con coloración madura e intermedia fuera similar". -- Tomado del resumen.
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    Abundance and activity of soil ammonia oxidizing microorganisms in colombian crops of economic importance.
    (Universidad de los Andes, 2017) Triviño Silva, Narda Jimena; Núñez, Jonathan; Arévalo, Ashly; Arango, Jacobo; Restrepo Restrepo, Silvia
    Nitrification rates, real-time quantitative PCR assay of AOA/AOB were coupled with a biological nitrification soil bioassay to revealed the nitrifiers abundance and potential BNI activity in different Colombian crop soils of economic importance: Rice (Oriza sativa), Maize (Zea mays), Common beans (Phaseolus vulgaris), Sugar cane (Saccharum officinarum),Cassava (Manihot esculenta), Brachiaria humidicola and 5 silvopastoral systems. The N initial quantification of NO3- and NR revealed significant differences between crops by the moment of soil sampling and stimulation of microorganism's activity. However, there was not an evident correlation between NR and abundances of AOA/AOB populations in all the crops evaluated as it was expected. The present results support the previous suggested importance of BNI as a strategy to manage N input in agricultural systems because agricultural management can strongly influence soil microbial activity and composition.
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    Acercamiento al diagnóstico genético en trastornos del espectro autista mediante análisis de variación en número de copias
    (Universidad de los Andes, 2019) Acero Ortega, Ana María; Lattig Matiz, María Claudia; Nuñez Ríos, Diana Leandra
    Los trastornos del espectro autista son desordenes del neurodesarrollo que presentan alteraciones en la interacción y comunicación social, rechazo a cambios en la rutina y comportamientos repetitivos; manifestaciones que se observan en los primeros años de vida. El autismo idiopático se caracteriza por no tener causa conocida ni base genética clara y no está asociado a otras enfermedades por lo que el pronóstico inicial es incierto. Por lo anterior, el objetivo de este estudio fue identificar CNVs de-novo y raros en individuos con diagnóstico de TEA idiopático a partir de microarreglos de alta resolución. Para esto, se utilizó los resultados crudos de análisis de microarreglo cromosómico previamente realizado con Infinium OmniExpress-24 BeadChip de 30 individuos que corresponden a diez tríos familiares. Para confirmar los datos arrojados por el programa GenomeStudio, se utilizaron dos valores; log R Ratio (LRR) y B allele frequence (BAF). Con esto, se encontró tres pacientes que mostraban CNVs no heredados que, además, eran raros. Luego de realizar la búsqueda de la importancia clínica de estos CNVs, se encontró que solo uno contenía genes y era una duplicación en 17p11.2. Esta microduplicación se ha reportado previamente con el Síndrome de Potocki-Lupski lo que lleva al diagnóstico de la paciente. En conclusión, teniendo en cuenta la heterogeneidad de la enfermedad, es necesario seguir investigando para poder tener un mayor acercamiento con la etiología del trastorno del espectro autista idiopático y en general de enfermedades complejas.
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    Acercamiento de la situación epidemiológica de Coxiella burnetii en Suramérica
    (Universidad de los Andes, 2020) Álvarez Osorio, Andrea Katherine; Parra Avila, Miguel Hernando; Montoya Ruiz, Carolina; Uribe Ardila, Jesús Alfredo; Zimmermann, Barbara Hanna; Camacho Vargas, Shirley María
    Coxiella burnetii is an intracellular, gram negative, spore-producing bacterium. It is characterized by being the etiologic agent of Q fever, a zoonosis that reports clinical affectations in humans and animals. Although it is not a high mortality disease, it is a debilitating pathology that could be avoided with early diagnosis and simple antibiotic treatment. Due to the limited information about the C. burnetii in South America, a systematic review of the epidemiology of this agent between the years 2000-2020 was done in order to consolidate the reported information. This review was accompanied by an evaluation of the presence of IgG Phase II antibodies in a population of Montelíbano, Córdoba. Epidemiological data evidenced the circulation of this agent in humans, animals and even food, with variable seropositivity values in terms of region regarding humans and animals. Infection by this bacterium can generate different clinical manifestations. In humans, those associated with the acute phase present the most registered cases while most animals suffered reproductivity affections. The risk factors are not clear yet, but in humans occupation and contact with animals are among the most common ones; whereas in animals the type of breed and sex are mainly suggested. In Colombia, the data suggest a seropositivity of 3.26% for the population analyzed in Córdoba. Consequently, it is evident that C.burnetii presents a real and underestimated threat to South America; reason why C.burnetii should be included in the differential diagnosis of diseases in the region.