Centro de Investigación de la Biodiversidad y Cambio Climático
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Associations among MHC genes, latitude, and avian malaria infections in the rufous‐collared sparrow (Zonotrichia capensis)

2024 , Juan Rivero de Aguilar , Omar Barroso , Bonaccorso, Elisa , Hector Cadena , Lucas Hussing , Josefina Jorquera , Javier Martinez , Josué Martínez‐de la Puente , Alfonso Marzal , Fabiola León Miranda , Santiago Merino , Nubia E. Matta , Marilyn Ramenofsky , Ricardo Rozzi , Carlos E. Valeris‐Chacín , Rodrigo A. Vásquez , Juliana A. Vianna , John C. Wingfield

The major histocompatibility complex (MHC) is a genetic region in jawed vertebrates that contains key genes involved in the immune response. Associations between the MHC and avian malaria infections in wild birds have been observed and mainly explored in the Northern Hemisphere, while a general lack of information remains in the Southern Hemisphere. Here, we investigated the associations between the MHC genes and infections with Plasmodium and Haemoproteus blood parasites along a latitudinal gradient in South America. We sampled 93 rufous-collared sparrows (Zonotrichia capensis) individuals from four countries, Colombia, Ecuador, Peru, and Chile, and estimated MHC-I and MHC-II allele diversity. We detected between 1–4 (MHC-I) and 1–6 (MHC-II) amino acidic alleles per individual, with signs of positive selection. We obtained generalized additive mixed models to explore the associations between MHC-I and MHC-II diversity and latitude. We also explored the relationship between infection status and latitude/biome. We found a non-linear association between the MHC-II amino acidic allele diversity and latitude. Individuals from north Chile presented a lower MHC genetic diversity than those from other locations. We also found an association between deserts and xeric shrublands and a lower prevalence of Haemoproteus parasites. Our results support a lower MHC genetic in arid or semi-arid habitats in the region with the lower prevalence of Haemoproteus parasites.

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The impact of termites on soil sheeting properties is better explained by environmental factors than by their feeding and building strategies

2022 , Jouquet, P. , Harit, A. , Hervé, V. , Moger, H. , Carrijo, T. , Donoso, David , Eldridge, D. , Ferreira da Cunha, H. , Choosai, C. , Janeau, J.-L. , Maeght, J.-L. , Thu, T.D. , Briandon, A. , Skali, M.D. , van Thuyne, J. , Mainga, A. , Pinzon Florian, O.P. , Issa, O.M. , Podwojewski, P. , Rajot, J.-L. , Henri-des-Tureaux, T. , Smaili, L. , Labiadh, M. , Boukbida, H.A.

Termites are key soil bioturbators in tropical ecosystems. Apart from mound nests constructed by some advanced lineages, most of the species use their faeces, oral secretions, debris, or soil aggregates to protect themselves from predators and desiccation when they go out to forage. Although this soil ‘sheeting’ is considered to play a key role in soil functioning, the properties of this termite-made material has been poorly studied. The few available data showed that sheeting properties are highly variable with positive, neutral or negative impacts on soil C and clay content, and consequently on soil aggregate stability. Therefore, the objective of this study was to determine the factors controlling the physical (particle size fractions and structural stability) and chemical (pH, electrical conductivity and carbon content) properties of soil sheeting produced by termite species encompassing all feeding and building categories using a dataset representative of an important diversity of biotopes coming from 21 countries from all continents colonized by termites. We showed that sheeting properties were explained by the properties of their environment, and especially by those of the bulk soil (linear relationships), followed in a lesser extent by the mean annual precipitation and biotope. Classic hypotheses related to termite feeding and building strategies were not hold by our analysis. However, the distinction of termites into fungus-growing and non-fungus growing species was useful when differentiating the impact of termites on soil electrical conductivity, C content, and structural stability. The large variability observed suggests the need to redefine termite functional groups based on their impacts on soil properties using a trait-based approach from morphological, anatomical and/or physiological traits. © 2022 Elsevier B.V.

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In vitro and in silico analysis of galanthine from Zephyranthes carinata as an inhibitor of acetylcholinesterase

2022 , Sierra, K. , de Andrade, J.P. , R. Tallini, L. , Osorio, E.H. , Yañéz, O. , Osorio, M.I. , Oleas Gallo, Nora Helena , García-Beltrán, O. , de S. Borges, W. , Bastida, J. , Osorio, E. , Cortes, N.

Zephyranthes carinata Herb., a specie of the Amaryllidoideae subfamily, has been reported to have inhibitory activity against acetylcholinesterase. However, scientific evidence related to their bioactive alkaloids has been lacking. Thus, this study describes the isolation of the alkaloids of this plant, and their inhibition of the enzymes acetylcholinesterase (eeAChE) and butyrylcholinesterase (eqBuChE), being galanthine the main component. Additionally, haemanthamine, hamayne, lycoramine, lycorine, tazettine, trisphaeridine and vittatine/crinine were also isolated. The results showed that galanthine has significant activity at low micromolar concentrations for eeAChE (IC50 = 1.96 μg/mL). The in-silico study allowed to establish at a molecular level the high affinity and the way galanthine interacts with the active site of the TcAChE enzyme, information that corroborates the result of the experimental IC50. However, according to molecular dynamics (MD) analysis, it is also suggested that galanthine presents a different inhibition mode that the one observed for galanthamine, by presenting interaction with peripheral anionic binding site of the enzyme, which prevents the entrance and exit of molecules from the active site. Thus, in vitro screening assays plus rapid computer development play an essential role in the search for new cholinesterase inhibitors by identifying unknown bio-interactions between bioactive compounds and biological targets. © 2022 The Authors

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Path for recovery: an ecological overview of the Jambato Harlequin Toad (Bufonidae: Atelopus ignescens) in its last known locality, Angamarca Valley, Ecuador

2024 , Mateo A. Vega-Yánez , Amanda B. Quezada-Riera , Blanca Rios-Touma , María del Carmen Vizcaíno-Barba , William Millingalli , Orlando Ganzino , Luis A. Coloma , Elicio E. Tapia , Nadine Dupérré , Mónica Páez-Vacas , David Parra-Puente , Daniela Franco-Mena , Gabriela Gavilanes , Salazar Valenzuela, David , Carlos A. Valle , Juan M. Guayasamin

The Jambato Harlequin toad (Atelopus ignescens), a formerly abundant species in the Andes of Ecuador, faced a dramatic population decline in the 1980s, with its last recorded sighting in 1988. The species was considered Extinct by the IUCN until 2016, when a fortuitous discovery of one Jambato by a local boy reignited hope. In this study, we present findings from an investigation conducted in the Angamarca parish, focusing on distribution, abundance, habitat preferences, ecology, disease susceptibility, and dietary habits of the species. In one year we identified 71 individuals at different stages of development in various habitats, with a significant presence in agricultural mosaic areas and locations near water sources used for crop irrigation, demonstrating the persistence of the species in a complex landscape, with considerable human intervention. The dietary analysis based on fecal samples indicated a diverse prey selection, primarily comprising arthropods such as Acari, Coleoptera, and ants. Amphibian declines have been associated with diseases and climate change; notably, our study confirmed the presence of the pathogen Batrachochytrium dendrobatidis (Bd), but, surprisingly, none of the infected Jambatos displayed visible signs of illness. When analyzing climatic patterns, we found that there are climatic differences between historical localities and Angamarca; the temporal analysis also exposes a generalized warming trend. Finally, in collaboration with the local community, we developed a series of management recommendations for terrestrial and aquatic environments occupied by the Jambato.

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Molecular Markers and Conservation of Plant Species in the Latin-America: The Case of Phaedranassa viridiflora (Amaryllidaceae)

2013 , Oleas Gallo, Nora Helena , Meerow A.W. , Francisco-Ortega J.

Phaedranassa viridiflora (Amaryllidaceae) is an endemic and endangered plant restricted to the Northern Andes in Ecuador. It is known in three locations where it is sympatric with other Phaedranassa species. Phaedranassa viridiflora is the only species of the genus with yellow flowers. We analyzed 13 microsatellite loci to elucidate the genetic structure of the populations of P. viridiflora. Our results provided the first evidence of natural hybridization in the genus (between P. viridiflora and P. dubia in the Pululahua crater of northern Ecuador). The central and southern populations did not show hybridization. Genetic diversity was the highest in the Pululahua population. Central and southern populations have a higher proportion of clones than Pululahua. Bayesian and cluster analysis suggest that the yellow flower type evolved at least three times along the Ecuadorean Andes. In contrast to other Phaedranassa species, Phaedranassa viridiflora shows lower genetic diversity, which is likely related to a vegetative reproductive strategy. © 2013 The New York Botanical Garden (outside the USA).

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A new minute Andean Pristimantis (Anura: Strabomantidae) from Venezuela

2012 , Barrio-Amorós C.L. , Guayasamin, Juan M. , Hedges S.B.

A new species of Pristimantis is described from the Venezuelan Andes. The new species is the smallest in its genus known in Venezuela and belongs to the Pristimantis unistrigatus Group. It differs from the rest of Venezuelan Andean congeners in body size (mean male SVL < 21.3 mm, female SVL < 26.3 mm), expanded discs on fingers and toes, absence of dorsolateral folds, and a distinctive call consisting in 2-5 cricket-like short notes. The new species inhabits the southwestern part of the Cordillera de Mérida in Venezuela and the Venezuelan side of the Cordillera Oriental de Colombia, and could be present on the Colombian portion of the cordillera as well. © 2012 Departamento de Ciências Biológicas.

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Urban soil management in the strategies for adaptation to climate change of cities in the Tropical Andes

2022 , Bonilla Bedoya, Santiago , Ángel Herrera, M. , Vaca, A. , Salazar, L. , Zalakeviciute, R. , Mejía, D. , López-Ulloa, M.

The unique characteristics of a city amplify the impacts of climate change; therefore, urban planning in the 21st century is challenged to apply mitigation and adaptation strategies that ensure the collective well-being. Despite advances in monitoring urban environmental change, research on the application of adaptation-oriented criteria remains a challenge in urban planning in the Global South. This study proposes to include urban land management as a criterion and timely strategy for climate change adaptation in the cities of the Tropical Andes. Here, we estimate the distribution of the soil organic carbon stock (OCS) of the city of Quito (2,815 m.a.s.l.; population 2,011,388; 197.09 km2) in the following three methodological moments: i) field/laboratory: city-wide sampling design established to collect 300 soil samples (0–15 cm) and obtain data on organic carbon (OC) concentrations in addition to 30 samples for bulk density (BD); ii) predictors: geographic, spectral and anthropogenic dimensions established from 17 co-variables; and iii) spatial modeling: simple multiple regression (SMRM) and random forest (RFM) models of organic carbon concentrations and density as well as OCS stock estimation. We found that the spatial modeling techniques were complementary; however, SMRM showed a relatively higher fit both (OC: r2 = 20%, BD: r2 = 16%) when compared to RFM (OC: r2 = 8% and BD: r2 = 5%). Thus, soil carbon stock (0–0.15 m) was estimated with a spatial variation that fluctuated between 9.89 and 21.48 kg/m2; whereas, RFM showed fluctuations between 10.38 and 17.67 kg/m2. We found that spatial predictors (topography, relative humidity, precipitation, temperature) and anthropogenic predictors (population density, roads, vehicle traffic, land cover) positively influence the model, while spatial predictors have little influence and show multicollinearity with relative humidity. Our research suggests that urban land management in the 21st century provides key information for adaptation and mitigation strategies aimed at coping with global and local climate variations in the cities of the Tropical Andes. © 2022 Elsevier B.V.

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Common but new: Bartramia rosamrosiae, a "new" widespread species of apple mosses (Bartramiales, Bryophytina) from the Mediterranean and western North America

2012 , Damayanti L. , Muñoz J. , Wicke S. , Symmank L. , Shaw B. , Frahm J.-P. , Quandt D.

Recent phylogenetic analyses challenged the traditional generic concept of the Bartramiaceae (apple mosses), especially with regard to the largest genus Bartramia. Although molecular analyses revealed the three Bartramia sections (Bartramia, Strictidium and Vaginella) to be monophyletic, they appeared in different parts of the inferred phylogenies and thus rendered the genus itself polyphyletic. In addition, Anacolia laevisphaera, a tropical montane species, appeared in the section Strictidium, weakening its character as a typical Mediterranean element. Although morphologically similar to members of the section, such as B. stricta, A. laevisphaera has been generally treated within the genus Anacolia based on sporophytic characters. In fact, Anacolia laevisphaera is often confused with B. stricta in sterile condition. A thorough analysis revealed another surprise, in placing A. laevisphaera sister to the Southern South American samples of Bartramia stricta, while the Mediterranean populations of "B. stricta" cluster with the Australian B. breutelii. Subsequent morphometric studies revealed three morpho-species in accordance with the polyphyletically resolved B. stricta. Here we describe the new species Bartramia rosamrosiae to accommodate the Mediterranean and western North American populations of what was traditionally treated as B. stricta. © 2012 Magnolia Press.

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A second species of the family allophrynidae (Amphibia: Anura)

2012 , Castroviejo-Fisher S. , Prez-Pea P.E. , Padial J.M. , Guayasamin, Juan M.

We describe Allophryne resplendens, a new species from two localities in the Amazon rainforest of Loreto, Peru, of the family Allophrynidae, which was monotypic until this discovery. The new species can be readily differentiated from Allophryne ruthveni on the basis of dorsal and ventral coloration both in life and in preservative, transverse processes of presacral II oriented anterolaterally (oriented laterally in A. ruthveni), 19 nucleotide autapomorphies for 761 base pairs (bp) of the mitochondrial gene 16S, and 16 for 923 bp of 12S. Maximum parsimony analysis of the mitochondrial gene 12S and a fragment of up to 1060 bp of 16S supports the new species as sister to A. ruthveni. Copyright © American Museum of Natural History 2012.

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Selection and Gene Duplication Associated With High-Elevation Diversification in Pristimantis, the Largest Terrestrial Vertebrate Genus

2024 , Nicholas Christodoulides , Veronica L Urgiles , Juan, Guayasamin , Anna E Savage , Mario dos Reis

The genus Pristimantis diversified in the tropical Andes mountains and is the most speciose genus of terrestrial vertebrates. Pristimantis are notable among frogs in that they thrive at high elevations (&gt;2,000 m) and are direct developers without a tadpole stage. Despite their ecological significance, little is known about the genetic and physiological traits enabling their success. We conducted transcriptomic analysis on seven Pristimantis species sampled across elevations in the Ecuadorean Andes to explore three hypotheses for their success: (i) unique genes are under selection relative to all other frogs, (ii) common selection occurs across all direct developers, or (iii) common selection occurs across all high-elevation frog clades. Comparative analysis with 34 frog species revealed unique positive selection in Pristimantis genes related to aerobic respiration, hemostasis, signaling, cellular transportation of proteins and ions, and immunity. Additionally, we detected positive selection across all direct developers for genes associated with oxygenase activity and metal ion binding. While many genes under selection in Pristimantis were not positively selected in other high-elevation frog species, we identified some shared genes and pathways linked to lipid metabolism, innate immunity, and cellular redox processes. We observed more positive selection in duplicated- versus single-copy genes, while relaxed purifying selection was prevalent in single-copy genes. Notably, copy number of an innate immunity complement gene was positively correlated with Pristimantis species elevation. Our findings contribute novel insights into the genetic basis of adaptation in Pristimantis and provide a foundation for future studies on the evolutionary mechanisms leading to direct development and coping with high elevations.

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