Biología
URI permanente para esta colecciónhttp://hdl.handle.net/11349/98237
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Ítem Patrones de distribución de los cangrejos de agua dulce de Colombia(Universidad Distrital Francisco José de Caldas) Castro Jaramillo, Juliana Alexandra; Arias Pineda, Julián Yessid; Valderrama Ardila, Carlos Humberto; Arias Pineda, Julián Yessid [0000-0002-2399-7953]The freshwater crabs of the families Trichodactylidae and Pseudothelphusidae found in Colombia have distinct habitats and altitudinal ranges. Trichodactylidae occurs between 100 and 900 m a.s.l., whereas Pseudothelphusidae inhabits elevations from 0 to 3000 m a.s.l., mainly in high Andean mountain ecosystems. In both families, species show fragmented distributions due to the extent and heterogeneity of their habitats. Geographic information was gathered from GBIF and ICN, removing duplicate coordinates and retaining only species with ≥10 records. A total of 208 records from 6 species of Trichodactylidae and 857 records from 16 species of Pseudothelphusidae were obtained. Distribution maps were created using ArcGis, and for Pseudothelphusidae, potential distribution models were also generated with the EcoNicheS package in Rstudio. For Trichodactylidae, the highest diversity was concentrated on the eastern slopes of the Eastern Cordillera, the lowlands of the Amazon, and part of the Orinoquía, associated with geological events such as the formation of the Pebas System (Miocene) and the uplift of the Eastern Cordillera. In Pseudothelphusidae, the greatest concentration occurred in the Colombian Andean region, linked to geological and migratory processes that favored their refuge in the area. These crabs play a key ecological role in freshwater ecosystems, contributing to ecological balance and serving as bioindicators of water quality. Their study is essential for guiding management and conservation plans that ensure the preservation of both the species and the ecosystems they inhabit.Ítem Profundidades ancestrales: Un viaje ilustrado a través del ecosistema marino(Universidad Distrital Francisco José de Caldas) Trespalacios Iguarán, Daniela; Enciso Romero, Santiago Alfonso; Dumar Rodríguez, Juan Camilo; Dumar Rodríguez Juan Camilo [0000-0001-6304-2580]The group of cartilaginous fishes, or “Elasmobranchs,” which includes sharks, rays, and chimaeras, has inhabited the oceans for over 450 million years, making it one of the oldest and most successful evolutionary lineages in history. Since their emergence in the Devonian period, they have developed numerous adaptations that allow them to thrive in their environments. Their evolutionary success is such that many species within this group are now apex predators at the top of the marine food chain. As a result, they have become a major focus of marine research due to their remarkable diversification. However, significant knowledge gaps remain regarding their biology and evolution. To address this, a bibliographic review was conducted to gather information on the evolution, taxonomy, and morphology of this group, with a special focus on Colombia. After reviewing approximately 130 articles, two main thematic axes were identified: first, taxonomy, evolutionary origin, and key adaptations; and second, current morphology, developed senses, reproduction, ecological importance, and threats. Based on this information, an educational booklet was developed to consolidate the findings from both thematic areas into a document that presents a broad range of information in a simple and accessible way for all audiences. The aim is to promote conservation by raising awareness about the threats faced by this group and highlighting their essential role within marine ecosystems.Ítem Desarrollo e implementación de un banco de imágenes para el Museo de Historia Natural de la Universidad Distrital Francisco José de Caldas(Universidad Distrital Francisco José de Caldas) Martínez Avendaño, Diego Alejandro; Rodríguez Bolaños, Abelardo; Rodríguez Bolaños Abelardo [0000-0002-2761-1712]Biological collections are fundamental pillars for research, education, and biodiversity conservation. In this context, the Museo de Historia Natural of the Universidad Distrital Francisco José de Caldas (MHNUD) has established itself as an academic and scientific reference, where most of the stored material is the result of numerous expeditions that have generated an extensive photographic archive. However, this visual material was scattered, which highlighted the need to create an organizational system to ensure its preservation and controlled access. In response, an internship was carried out at the museum, during which an image bank was designed and implemented. This bank brings together photographs of fauna, flora, landscapes, people, and field methods, and is accompanied by a detailed protocol that establishes guidelines for its use and management. The image bank is divided into two main components: a metadata matrix in Excel that records the essential information of each image, and the university's institutional repository, which allows for its visualization. To test its functionality, the Miraflores 2017 Expedition was used as a reference. The upload of the initial files demonstrated the system's viability and allowed for adjustments to be made to the protocol, which is replicable, practical, and adaptable to future projects. This work sets a precedent for digitization processes at the MHNUD.Ítem Estudio morfométrico comparativo de la capa granular externa en cerebelos humanos durante el desarrollo fetal entre las semanas 10 y 32 de gestación en humanos con exposición a hipoxia y sin compromiso hipóxico crónico(Universidad Distrital Francisco José de Caldas) Cifuentes Parada, Andrés Leonardo; Rodríguez Saza, Freddy; Rueda Esteban, Roberto Javier; Rodríguez Saza, Freddy [0000-0001-9709-4258]Fetal hypoxia, understood as oxygen deficiency during pregnancy, is of great medical interest as it is one of the main causes of pregnancy complications and generates alterations in the central nervous system (CNS). In the cerebellum, it can lead to complications that result in cognitive, behavioral, and language impairments. In this study, a morphometric analysis was carried out on 22 samples of human fetal cerebella of different gestational ages, with the aim of evaluating the effect of hypoxia on the thickness of the external granular layer and Purkinje cells, based on histological sections stained with hematoxylin-eosin. A MANOVA statistical analysis was applied using Python and PAST5, resulting in no significant difference in the variation of the external granular layer thickness between fetuses with hypoxia and those without hypoxic exposure, although it could alter the cellular maturation of this layer, which opens the opportunity for further in vivo studies.Ítem Caracterización de comunidades bacterianas del suelo en áreas de mayor conservación de antiguos campos elevados del predio “El Bosque”(Universidad Distrital Francisco José de Caldas) Patiño López, Angela María; Rodríguez Saza, Freddy; García Caycedo, Luz Andrea; Rodríguez Saza, Freddy [0000-0001-9709-4258]; García Caycedo, Luz Andrea [0009-0006-6574-2277]In the Bogotá Savanna, there are remnants of hydraulic farming systems developed by the pre-Hispanic communities that inhabited this territory. These systems, composed of raised fields and canals, enabled these populations to coexist with and harness water resources by modifying the landscape while using the soil for agriculture. The success of these structures was such that they supported the communities’ subsistence and growth for hundreds of years, until the arrival of the Spanish, when they were abandoned. Studies on these raised fields and canals have been carried out at the edaphological level, but not at the microbiological level. In this study, a bacterial characterization of the raised fields was conducted through recovery, isolation, and identification in culture media, complemented by a metagenomic analysis. The results reveal the high fertility of the soils in these structures, as well as the diversity of species found and the balance among functional groups.Ítem Modelado molecular de la interacción entre las proteínas virales del FPLV y proteínas de membrana de células gastrointestinales de gato doméstico (Felis catus)(Universidad Distrital Francisco José de Caldas) Pérez Patiño, Haydi Daniela; Rodríguez Saza, Freddy; Rodríguez Saza, Freddy [0000-0001-9709-4258]Feline panleukopenia (FPL) is a viral disease caused by the feline panleukopenia virus (FPLV), whose capsid is mainly composed of proteins VP1 and VP2, which are involved in tropism, antigenicity, and the interaction with the feline transferrin receptor (TfRf). Despite its clinical and epidemiological relevance, gaps remain in the understanding of the structural determinants that mediate this interaction. The aim of this work was to analyze, through computational tools, the VP2–TfRf interaction to identify key contacts and conformational patterns with functional relevance. The research was conducted in three phases: (1) a systematic literature review and phylogenetic analysis of VP2, incorporating sequences from FPLV and closely related parvoviruses; (2) three-dimensional modeling and in silico validation of VP1 and VP2, using optimized alignment strategies and template selection; and (3) molecular dynamics simulation of the VP2–TfR1 complex to assess its stability and characterize inter-residue contacts. The results confirm a high structural homology between FPLV and canine parvovirus (CPV), allowing extrapolation of capsid–receptor binding mechanisms. The modeling of VP1 and VP2 yielded high-quality structures, validated by stereochemical and potential energy parameters. Molecular dynamics showed that the VP2–TfR1 complex maintains a stable interface over 100 ns, with persistent contacts and localized conformational changes that favor receptor binding, supporting the hypothesis that localized flexibility in VP2 is key for specific recognition of the TfRf. Taken together, this study provides conceptual and methodological foundations for the design of inhibitors aimed at blocking viral entry and for vaccine optimization. It also demonstrates the value of in silico approaches in structural virology, offering tools to address knowledge gaps on FPLV biology and to support prevention strategies in both domestic and wild felines.Ítem Diagnóstico paleopatológico y molecular de Treponema pallidum en una muestra ósea antigua del sur de la Sabana de Bogotá(Universidad Distrital Francisco José de Caldas) Robayo Mayorga, María José; Rodríguez Saza, Freddy; Rodríguez Saza, Freddy [0000-0001-9709-4258]Paleopathology enables the study of diseases in ancient populations through the analysis of human remains, integrating tools from molecular biology, histology, and archaeology. This study presents a differential diagnosis applied to an individual with lesions compatible with a chronic infectious disease, recovered from the archaeological site Estación Portal Tunal, located in the southern Sabana de Bogotá (Colombia), radiocarbon dated to 720 ± 30 years BP (Late Muisca period). An integrative approach combining macroscopic, radiological, histological, and molecular analyses was employed to evaluate the possible presence of Treponema pallidum. The bone lesions, affecting both tibiae (predominantly the right), included periostitis, osteitis, and Harris lines; histological analysis, conducted through stereoscopy, conventional light microscopy, scanning electron microscopy, and polarized light, revealed structures such as Polster, Grenzstreifen, sinuous lacunae, enlarged Haversian canals, and resorption lacunae, all indicative of chronic inflammation. Molecular detection targeting the tpp15 gene enabled the recovery and confirmation of T. pallidum sequences through NGS and phylogenetic analysis, constituting the first molecular evidence of treponematosis in pre-Hispanic remains from Colombia. Additionally, a Python workflow was implemented to compare the tp92 gene between T. pallidum subsp. pallidum and T. pallidum subsp. pertenue, using publicly available complete genomes. This tool, designed for educational and exploratory purposes, automates sequence retrieval, identifies mutations, and visualizes key differences that, despite a genomic identity greater than 99.5%, may be associated with variations in transmission, tropism, and clinical manifestations. The findings expand current knowledge on the historical distribution of T. pallidum in the Americas and highlight the potential of integrating bioarchaeological, molecular, and bioinformatic approaches in the study of ancient pathogens.Ítem Uso de señales multimodales para el reconocimiento y delimitación de especies en pinzones del género Arremon. Estudios previos(Universidad Distrital Francisco José de Caldas) Ramos Montenegro , Laura Daniela; Rodríguez Saza, Freddy; Avendaño Carreño, Jorge Enrique; Rodríguez Saza, Freddy [0000-0001-9709-4258]Signal recognition is fundamental in animal communication, particularly in birds, where song and plumage enable individual identification, hierarchy establishment, and the regulation of social interactions. In sympatric contexts, reinforcement selection may favor more differentiated signals that facilitate species-specific recognition and promote reproductive isolation. However, in allopatric populations—where selective pressure to distinguish phenotypes is reduced—the functional role of these signals remains poorly understood. In this study, we evaluated the recognition of phenotypic signals in Arremon assimilis through territorial intrusion experiments using taxidermic mounts and playback. Aggressive responses were quantified through a PCA-derived index, revealing stronger reactions to homogeneous treatments (Hom–Hom, Het–Het), whereas mixed combinations elicited weaker responses. These results suggest partial recognition between divergent phenotypes; however, the low number of replicates per treatment limits the ability to draw definitive conclusions. Therefore, increasing the number of experiments per treatment is recommended to enhance statistical inference and obtain more robust and representative insights into the behavioral patterns observed.Ítem Caracterización del microbioma asociado a muestras de cálculo dental de un individuo del periodo Muisca Tardío(Universidad Distrital Francisco José de Caldas) Largo López, Julián Andrés; Rodríguez Saza, Freddy; Rodríguez Saza, Fredy [0000-0001-9709-4258]The oral microbiome constitutes one of the most diverse ecosystems in the human body, with more than 1,200 bacterial species distributed across multiple oral niches, such as teeth, tongue, and gums, whose environmental conditions favor the formation of biofilms and complex microbial dynamics. Its study has gained relevance due to its impact on systemic health, including cardiovascular and periodontal diseases. The development of next-generation sequencing (NGS) techniques, especially whole metagenome shotgun sequencing (WMS), has made it possible to characterize microbial communities without the need for culture, identify functional genetic profiles, and establish databases such as HOMD, where 57% of oral bacteria have currently been characterized. Metagenomics has also opened new perspectives in the analysis of ancient DNA (aDNA), highlighting dental calculus as an exceptional archaeological substrate due to its ability to preserve microbiota, endogenous DNA, proteins, and dietary signals. However, the study of aDNA faces challenges associated with molecular fragmentation and contamination, which has driven the development of bioinformatic tools to authenticate ancient sequences and minimize false positives. Complementarily, scanning electron microscopy (SEM) has enabled the characterization of bacterial morphologies and the assessment of taphonomic damage. To date, studies on ancient oral microbiomes have been concentrated mainly in Europe and North America, with limited contributions in Latin America, where only Mexico, Chile, and Puerto Rico have developed research in this field. In Colombia, there are no studies on the ancient oral microbiome based on dental calculus, which creates a gap in knowledge about pre-Hispanic Andean communities. This project proposes an initial exploration in the Bogotá Savanna region, using metagenomics and aDNA analysis, together with histological techniques, to provide novel information on ancestral microbial diversity and its relationship with the health, diet, and environment of ancient populations.Ítem Descripción histológica del cerebro y órganos sensoriales del milpiés neotropical Pycnotropis sp. (Polydesmida: Aphelidesmidae)(Universidad Distrital Francisco José de Caldas) Payares Castro, Luisa Fernanda; García García, Alexander; García García, Alexander [0000-0001-9905-003X]Millipedes are key components of terrestrial ecosystems, actively participating in the decomposition of organic matter in soil and distributed across much of tropical and neotropical forests. However, aspects of their biology remain scarce or fragmented, requiring further revision, particularly in their neurobiology. Research on the nervous system (NS) in myriapods especially studies involving sensory organs is significant from both ecological and evolutionary perspectives, as it provides comparative neuroanatomical data and helps identify group-specific characteristics. Therefore, this study focuses on describing the brain and sensory organs of the neotropical millipede species Pycnotropis taenia (Aphelidesmidae), here taxonomically confirmed. We examine in detail the brain structure and its components using hematoxylin and eosin staining. Additionally, we characterize antennal sensilla typologically through scanning electron microscopy. Our observations revealed a small, compact brain with three cerebral neuromeres lacking clear separation, where the protocerebrum is the most prominent. The brain exhibits a characteristic cortex-neuropil organization, along with associated neuropils such as mushroom bodies and olfactory glomeruli. Furthermore, typical globular cell clusters, common in Myriapoda brains, were identified. At the sensillar level, seven types of sensilla (including subtypes) were distinguished on the antennae. Notably, we propose a subdivision of trichoid sensilla into two subtypes and describe species-specific variations, including a serrated termination of the apical cone. This pioneering study establishes a foundation for future research using robust immunostaining techniques and underscores the need to further explore millipedes as understudied neurobiological models.