Esta sección incluye una lista de los últimos artículos científicos del IPNA publicados en revistas incluidas en el Science Citation Index (SCI).
En DIGITAL.CSIC, repositorio institucional del CSIC, pueden encontrar el listado completo de artículos científicos desde 1962, así como otras colecciones de interés como congresos, tesis, libros, material divulgativo, etc. del centro. El objetivo de DIGITAL.CSIC es organizar, preservar y difundir en acceso abierto los resultados de nuestra investigación.
En el repositorio institucional del CSIC, pueden encontrar el listado completo de artículos científicos, así como otras colecciones de interés como congresos, tesis, libros, material divulgativo, etc.
Análisis de la Producción Científica del IPNA 2014-2019: análisis bibliométrico realizado a partir de datos recogidos en Scopus y Web of Science.
Dust and tropical PMx aerosols in Cape Verde: Sources, vertical distributions and stratified transport from North Africa
We investigated the sources and processes affecting the vertical distribution of tropical PMx aerosols (particulate matter -PM- smaller than 10, 2.5 and 1 μm, PM10, PM2.5 and PM1, respectively) in the low troposphere of Santo Antão and São Vicente islands, in Cape Verde archipelago, a region where a better understanding of aerosols is needed due to their involvement in tropical meteorology and their impact on air quality, ocean and climate. We found that local sources had a low-scale impact. From transect measurements at ground level, we found that PMx levels were predominantly low, except near to PMx sources, where distinctive PM1 / PM2.5 ratios were measured, linked to vehicle exhaust (0.96), biomass burning (0.67) and Cape Verdean dust (0.36) emissions. The depth of the marine boundary layer (MBL) and the vertical distributions of PMx showed wide variability prompted by meteorological conditions. The trade winds prevailed in the MBL, whereas other airflows were situated above it: North-Atlantic, African easterly airflow and Saharan Air Layer. Under North-Atlantic airflow conditions, the MBL extended to 1400 m above sea level (m.a.s.l.). Above this altitude, PMx concentrations decreased quickly (< 3 μg/m3) due to the free troposphere conditions. Under Saharan dust conditions, the MBL was confined to just 70 m.a.s.l., whereas a complex dust stratification was observed above, characterized by alternating dry air layers with high dust loads (PM10 ~ 100 μg/m3) and more humid air layers with lower aerosol loads (PM10 ~ 40 μg/m3). Within the dry easterly African airflow occurring above the marine stratocumulus typical of the MBL top (placed at 500 m.a.s.l.), we detected layers enriched in hydrophilic aerosols (PM10: ~ 8 μg/m3). These were imbedded in relatively humid air (RH ~48%), probably linked to secondary aerosol formation by in-cloud processes in the marine stratocumulus situated below. We found that PMx transport from North Africa, both under dust and dust-free conditions, is associated with complex vertical stratifications, even within the dusty Saharan Air Layer.
Rodríguez, Sergio; López-Darias, Jessica
Litosetoenins A–E, Diterpenoids from the Soft Coral Litophyton setoensis, Backbone-Rearranged through Divergent Cyclization Achieved by Epoxide Reactivity Inversion
|Litosetoenins A–E (1–5), five new ring-rearranged serrulatane-type diterpenoids with a common tricyclo[3.0.4]decane core, along with a known diterpenoid glycoside (6), a related known diterpenoid (7), and four known sesquiterpenoids (8–11), were isolated from a Balinese soft coral Litophyton setoensis. Spirolitosetoenin A (5a) and isospirolitosetoenin A (5b), featuring an unprecedented spiro[4,5]decane core, were obtained after treatment of compound 5 with HCl in methanol. The structures of new compounds were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance approach, and chemical methods. A plausible biosynthetic pathway involving an unusual divergent biogenesis was proposed.|
Li, Song-Wei; Mudianta, I. Wayan; Cuadrado, Cristina; Geng, Li; Yudasmara, Gede A.; Setiabudi, Gede I. ;Hernández Daranas, Antonio; Guo, Yue-Wei
A unified model of species abundance, genetic diversity, and functional diversity reveals the mechanisms structuring ecological communities
Biodiversity accumulates hierarchically by means of ecological and evolutionary processes and feedbacks. Within ecological communities drift, dispersal, speciation, and selection operate simultaneously to shape patterns of biodiversity. Reconciling the relative importance of these is hindered by current models and inference methods, which tend to focus on a subset of processes and their resulting predictions. Here we introduce Massive Eco-evolutionary Synthesis Simulations (MESS), a unified mechanistic model of community assembly, rooted in classic island biogeography theory, which makes temporally explicit joint predictions across three biodiversity data axes: i) species richness and abundances; ii) population genetic diversities; and iii) trait variation in a phylogenetic context. Using simulations we demonstrate that each data axis captures information at different timescales, and that integrating these axes enables discriminating among previously unidentifiable community assembly models. MESS is unique in generating predictions of community-scale genetic diversity, and in characterizing joint patterns of genetic diversity, abundance, and trait values. MESS unlocks the full potential for investigation of biodiversity processes using multi-dimensional community data including a genetic component, such as might be produced by contemporary eDNA or metabarcoding studies. We combine with supervised machine learning to fit the parameters of the model to real data and infer processes underlying how biodiversity accumulates, using communities of tropical trees, arthropods, and gastropods as case studies that span a range of data availability scenarios, and spatial and taxonomic scales.
Overcast, Isaac; Ruffley, Megan; Rosindell, James; Harmon, Luke ; Borges, Paulo A. V.; Emerson, Brent C.; Etienne, Rampal S.; Gillespie, Rosemary; Krehenwinkel, Henrik; Mahler, D. Luke; Massol, Francois; Parent, Christine E.; Patiño, Jairo; Peter, Ben; Week, Bob; Wagner, Catherine; Hickerson, Michael J.; Rominger, Andrew
Macroclimatic structuring of spatial phylogenetic turnover in liverworts
Phylogenetic turnover has emerged as a powerful tool to identify the mechanisms by which biological communities assemble. When significantly structured along environmental gradients, phylogenetic turnover evidences phylogenetic niche conservatism, a critical principle explaining patterns of species distributions at different spatio–temporal scales. Here, we quantify the contribution of geographic and macroclimatic drivers to explain patterns of phylogenetic turnover in an entire phylum of land plants, namely liverworts. We further determine whether climatic niche conservatism has constrained the distribution of liverworts in the course of their evolutionary history. Two datasets, one insular, focused on 60 archipelagos and including 2346 species, and the second global, including 6334 species in 451 oceanic and continental operational geographic units (OGUs) worldwide, were assembled. Phylogenetic turnover among OGUs was quantified through πst statistics. πst-through-time profiles were generated at 1 Myr intervals along the phylogenetic time-scale and used to compute the correlation between πst, current geographic distance and macroclimatic variation with Mantel tests based on Moran spectral randomization to control for spatial autocorrelation. The contribution of macroclimatic variation to phylogenetic turnover was about four-times higher than that of geographic distance, a pattern that was consistently observed in island and global geographic settings, and with datasets including or excluding species-poor OGUs. The correlation between phylogenetic turnover and geographic distance rapidly decayed at increasing phylogenetic depth, whereas the relationship with macroclimatic variation remained constant until 100 Mya. Our analyses reveal that changes in the phylogenetic composition among liverwort floras across the globe are primarily shaped by macroclimatic variation. They demonstrate the relevance of macroclimatic niche conservatism for the assembly of liverwort floras over very large spatial and evolutionary time scales, which may explain why such a pervasive biodiversity pattern as the increase of species richness towards the tropics also applies to organisms with high dispersal capacities.
Collart, Flavien; Wang, Jian ;Patiño, Jairo; Hagborg, Anders; Söderström, Lars; Goffinet, Bernard; Magain, Nicolas; Hardy, Olivier J.; Vanderpoorten, Alain
Trophic strategies of two sympatric endemic pigeons in insular ecosystems: a framework for understanding spatiotemporal frugivory interactions
Pigeons are considered to play key ecological roles in frugivory and seed dispersal. They have colonised numerous oceanic islands and diversified into several species in sympatry. How these species coexist in similar niches is poorly understood although dietary separation is among the mechanisms suggested to avoid trophic overlap. We investigated the trophic ecology of the two endemic Columba species co-occurring in the laurel forest and thermosclerophyllous relicts of two of the Canary Islands. This study includes diet description in spatiotemporal terms, its relationship with fruit availability and seed treatment in 10 study areas established on La Palma and La Gomera. We used non-invasive DNA analysis to identify the faeces of the two con-generic species and microhistological methods to examine their diets. The degree of trophic overlap was evaluated by niche similarity and breadth indices. Molecular faecal sampling determined the spatiotemporal distribution of both pigeons to identify their areas of coexistence. These frugivorous pigeons’ diets did not differ concerning the main plant species, but they diverged quantitatively in the proportions and parts of plants consumed. Lauraceae fruits were their staple foods although Rhamnaceae and some Fabaceae and Solanaceae were also important. Both pigeons showed selective preferences for some fruits. Significant spatiotemporal variations in their diets were observed along with a general tendency to increase fruit intake at its ripening times. Our results suggest that different trophic strategies facilitate the coexistence of these frugivorous columbids. These pigeons act as seed dispersers and/or predators depend ing on seed features (size and hardness), and this may have valuable implications for their conservation.
Marrero, Patricia; Nogales, Manuel
Coming of age for COI metabarcoding of whole organism community DNA: towards bioinformatic harmonisation
Metabarcoding of DNA extracted from community samples of whole organisms (whole organism community DNA, wocDNA) is increasingly being applied to terrestrial, marine and freshwater metazoan communities to provide rapid, accurate and high resolution data for novel molecular ecology research. The growth of this field has been accompanied by considerable development that builds on microbial metabarcoding methods to develop appropriate and efficient sampling and laboratory protocols for whole organism metazoan communities. However, considerably less attention has focused on ensuring bioinformatic methods are adapted and applied comprehensively in wocDNA metabarcoding. In this study we examined over 600 papers and identified 111 studies that performed COI metabarcoding of wocDNA. We then systematically reviewed the bioinformatic methods employed by these papers to identify the state-of-the-art. Our results show that the increasing use of wocDNA COI metabarcoding for metazoan diversity is characterised by a clear absence of bioinformatic harmonisation, and the temporal trends show little change in this situation. The reviewed literature showed (i) high heterogeneity across pipelines, tasks and tools used, (ii) limited or no adaptation of bioinformatic procedures to the nature of the COI fragment, and (iii) a worrying underreporting of tasks, software and parameters. Based upon these findings we propose a set of recommendations that we think the wocDNA metabarcoding community should consider to ensure that bioinformatic methods are appropriate, comprehensive and comparable. We believe that adhering to these recommendations will improve the long-term integrative potential of wocDNA COI metabarcoding for biodiversity science.
Creedy, Thomas; Andújar, Carmelo; Noguerales, Víctor; Overcast, Isaac; Papadopoulou, Anna; Morlon, Hélène; Vogler, Alfried; Emerson, Brent C.; Arribas, Paula
Dispersal limitations and long-term persistence drive differentiation from haplotypes to communities within a tropical sky-island: evidence from community metabarcoding
Neutral theory proposes that dispersal stochasticity is one of the main drivers of local diversity. Haplotypes-level genetic variation can now be efficiently sampled from across whole communities, thus making it possible to test neutral predictions from the genetic to species-level diversity, and higher. However, empirical data is still limited, with the few studies to date coming from temperate latitudes. Here, we focus on a tropical mountain within the Transmexican Volcanic Belt to evaluate spatially fine-scale patterns of arthropod community assembly to understand the role of dispersal limitation and landscape features as drivers of diversity. We sampled whole-communities of arthropods for eight orders at a spatial scale ranging from 50 m to 19 km, using whole community metabarcoding. We explored multiple hierarchical levels, from individual haplotypes to lineages at 0.5, 1.5, 3, 5, 7.5% similarity thresholds, to evaluate patterns of richness, turnover, and distance decay of similarity with isolation-by-distance and isolation-by resistance (costs to dispersal given by landscape features) approaches. Our results showed that distance and altitude influence distance decay of similarity at all hierarchical levels. This holds for arthropod groups of contrasting dispersal abilities, but with different strength depending on the spatial scale. Our results support a model where local-scale differentiation mediated by dispersal constraints, combined with long-term persistence of lineages, is an important driver of diversity within tropical sky islands.
Gálvez-Reyes, Nancy; Arribas, Paula; Andújar, Carmelo; Emerson, Brent C.; Piñero, Daniel; Mastretta-Yanes, Alicia
Metapopulation structure modulates sexual antagonism
Despite the far-reaching evolutionary implications of sexual conflict, the effects of metapopulation structure, when populations are subdivided into several demes connected to some degree by migration, on sexual conflict dynamics are unknown. Here, we used experimental evolution in an insect model system, the seed beetle Callosobruchus maculatus, to assess the independent and interacting effects of selection histories associated with mating system (monogamy vs. polygamy) and population subdivision on sexual conflict evolution. We confirm traditional predictions from sexual conflict theory by revealing increased resistance to male harm in females from populations with a history of intense sexual selection (polygamous populations) compared to females from populations with a history of relaxed sexual selection (monogamous populations). However, selection arising from metapopulation structure reversed the classic pattern of sexually antagonistic coevolution and led to reduced resistance in females from polygamous populations. These results underscore that population spatial structure moderates sexual selection and sexual conflict, and more broadly, that the evolution of sexual conflict is contingent on ecological context. The findings also have implications for population dynamics, conservation biology, and biological control.
Rodríguez-Expósito, Eduardo; García-González, Francisco
The Bone Regeneration Capacity of BMP-2 + MMP-10 Loaded Scaffolds Depends on the Tissue Status
Biomaterials-mediated bone formation in osteoporosis (OP) is challenging as it requires tissue growth promotion and adequate mineralization. Based on our previous findings, the development of scaffolds combining bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 10 (MMP-10) shows promise for OP management. To test our hypothesis, scaffolds containing BMP-2 + MMP-10 at variable ratios or BMP-2 + Alendronate (ALD) were prepared. Systems were characterized and tested in vitro on healthy and OP mesenchymal stem cells and in vivo bone formation was studied on healthy and OP animals. Therapeutic molecules were efficiently encapsulated into PLGA microspheres and embedded into chitosan foams. The use of PLGA (poly(lactic-co-glycolic acid)) microspheres as therapeutic molecule reservoirs allowed them to achieve an in vitro and in vivo controlled release. A beneficial effect on the alkaline phosphatase activity of non-OP cells was observed for both combinations when compared with BMP-2 alone. This effect was not detected on OP cells where all treatments promoted a similar increase in ALP activity compared with control. The in vivo results indicated a positive effect of the BMP-2 + MMP-10 combination at both of the doses tested on tissue repair for OP mice while it had the opposite effect on non-OP animals. This fact can be explained by the scaffold’s slow-release rate and degradation that could be beneficial for delayed bone regeneration conditions but had the reverse effect on healthy animals. Therefore, the development of adequate scaffolds for bone regeneration requires consideration of the tissue catabolic/anabolic balance to obtain biomaterials with degradation/release behaviors suited for the existing tissue status.
García-García, Patricia; Reyes, Ricardo; Rodríguez, José Antonio; Martín, Tomás; Evora, Carmen; Díaz-Rodríguez, Patricia; Delgado, Araceli
Changes in the structure of seed dispersal networks when including interaction outcomes from both plant and animal perspectives
Interaction frequency is the most common currency in quantitative ecological networks, although interaction quality can also affect benefits provided by mutualisms. Here, we evaluate if interaction quality can modify network topology, species' role and whether such changes affect community vulnerability to species loss. We use a well-examined study system (bird–lizard and fleshy-fruited plants in the ‘thermophilous' woodland of the Canary Islands) to compare network and species-level metrics from a network based on fruit consumption rates (interaction frequency, IF), against networks reflecting functional outcomes: a seed dispersal effectiveness network (SDE) quantifying recruitment, and a fruit resource provisioning network (FRP), accounting for the nutrient supply of fruits. Nestedness decreased in the FRP and the SDE networks, due to the lack of association between fruit consumption rates and 1) nutrient content and; 2) recruitment at the seed deposition sites, respectively. The FRP network showed lower niche overlap due to resource use complementarity among frugivores. Interaction evenness was lower in the SDE network, in response to a higher dominance of lizards in the recruitment of heliophilous species. Such changes, however, did not result in enhanced vulnerability against extinctions. At the plant species level, strength changed in the FRP network in frequently consumed or highly nutritious species. The number of effective partners decreased for species whose seeds were deposited in unsuitable places for recruitment. In frugivores, strength was consistent across networks (SDE vs IF), showing that consumption rates outweighed differences in dispersal quality. In the case of lizards, the increased importance of nutrient-rich species resulted in a higher number of effective partners.
Our work shows that although frequency strongly impacts interaction effects, accounting for quality improves our inferences about interaction assembly and species role. Thus, future studies including interaction outcomes from both partners' perspectives will provide valuable insights about the net effects of mutualistic interactions.
González-Castro, Aaron; Morán-López, Teresa; Nogales, Manuel; Traveset, Anna
Acrylonitrile Derivatives against Trypanosoma cruzi: In Vitro Activity and Programmed Cell Death Study
The neglected infection known as Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, results in more than 7000 deaths per year, with an increasing number of cases in non-endemic areas such as Europe or the United States. Moreover, with the current available therapy, only two compounds which are active against the acute phase of the disease are readily available. In addition, these therapeutic agents display multiple undesired side effects such as high toxicity, they are expensive, the treatment is lengthy and the resistant strain has emerged. Therefore, there is a need to find new compounds against Chagas disease which should be active against the parasite but also cause low toxicity to the patients. In the present work, the activity of novel acrylonitriles against Trypanosoma cruzi was evaluated as well as the analysis of the physiological events induced in the treated parasites related to the cell death process. Hence, the characteristic features of an apoptosis-like process such as chromatin condensation and mitochondrial membrane potential, among others, were studied. From the 32 compounds tested against the epimastigote stage of T. cruzi, 11 were selected based on their selectivity index to determine if these compounds were able to induce programmed cell death (PCD) in the treated parasites. Furthermore, acrylonitriles Q5, Q7, Q19, Q27 and Q29 were shown to trigger physiological events related in the PCD. Therefore, this study highlights the therapeutic potential of acrylonitriles as novel trypanocidal agents.
Bethencourt-Estrella, Carlos J.; Delgado-Hernández, Samuel; López-Arencibia, Atteneri; San Nicolás-Hernández, Desirée; Sifaoui, Ines; Tejedor, David; García-Tellado, Fernando; Lorenzo-Morales, Jacob; Piñero, José E.
Dynamic Nucleophilic Aromatic Substitution of Tetrazines
A dynamic nucleophilic aromatic substitution of tetrazines (SNTz) is presented herein. It combines all the advantages of dynamic covalent chemistry with the versatility of the tetrazine moiety. Indeed, libraries of compounds or sophisticated molecular structures can be easily obtained, which are susceptible to post-functionalization by inverse electron demand Diels–Alder (IEDDA) reaction, which also locks the exchange. Additionally, the structures obtained can be disassembled upon the application of the right stimulus, either UV irradiation or a suitable chemical reagent. Moreover, SNTz is compatible with the imine chemistry of anilines. The high potential of this methodology has been proved by building two responsive supramolecular systems: A macrocycle that displays a light-induced release of acetylcholine; and a truncated [4+6] tetrahedral shape-persistent fluorescent cage, which is disassembled by thiols unless it is post-stabilized by IEDDA.
Santos, Tanausú; Rivero, David S.; Pérez-Pérez, Yaiza; Martín-Encinas, Endika; Pasán, Jorge; Hernández Daranas, Antonio; Carillo, Romen
The Chemistry of Reactive Oxygen Species (ROS) Revisited: Outlining Their Role in Biological Macromolecules (DNA, Lipids and Proteins) and Induced Pathologies
Living species are continuously subjected to all extrinsic forms of reactive oxidants and others that are produced endogenously. There is extensive literature on the generation and effects of reactive oxygen species (ROS) in biological processes, both in terms of alteration and their role in cellular signaling and regulatory pathways. Cells produce ROS as a controlled physiological process, but increasing ROS becomes pathological and leads to oxidative stress and disease. The induction of oxidative stress is an imbalance between the production of radical species and the antioxidant defense systems, which can cause damage to cellular biomolecules, including lipids, proteins and DNA. Cellular and biochemical experiments have been complemented in various ways to explain the biological chemistry of ROS oxidants. However, it is often unclear how this translates into chemical reactions involving redox changes. This review addresses this question and includes a robust mechanistic explanation of the chemical reactions of ROS and oxidative stress.
Andrés Juan, Celia; Pérez de Lastra, José Manuel; Plou Gasca, Francisco José; Pérez-Lebeña, Euardo
Biodiversity monitoring using environmental DNA
Monitoring biodiversity is essential to protect, preserve and restore ecosystems, particularly in the context of current challenges such as climate change, habitat destruction and globalization (Baird & Hajibabaei, 2012). Biomonitoring is needed for developing biotic indices for assessing ecological status, measuring impacts of anthropogenic activities in natural ecosystems, evaluating biodiversity loss, surveying nonindigenous species, conservation, and identifying cryptic species (Balvanera et al., 2006; Fišer et al., 2018). Thus, spatially and temporally structured biomonitoring activities provide a powerful tool for the implementation of regional, national and international regulations, directives and policies for nature conservation. However substantial impediments exist including access to remote locations, limited specialist taxonomic knowledge, cost, slow pace of human-driven data analyses, and typically low sensitivity for detection of rare and elusive species (Zinger et al., 2020). These drawbacks are often translated into expensive monitoring activities with limited spatial, temporal and taxonomic coverage. In this context, new approaches for biomonitoring are being explored, among which advanced DNA-based technologies are emerging (Kissling et al., 2018). The field of biodiversity monitoring through the analysis of the pool of DNA isolated from environmental samples, referred to as environmental DNA or eDNA (Pawlowski et al., 2020; Taberlet et al., 2012), is rapidly growing. This growth is being driven through improved approaches for sampling, data generation and analyses, and with recent advances on how eDNA should be interpreted for biodiversity assessments (Bohmann et al., 2014). The success of eDNA-based biomonitoring is reflected in exponential growth of publications within this area and increasing submissions to Molecular Ecology Resources in particular (Figure 1). Molecular Ecology Resources aims to publish high quality eDNA studies that serve as broad resources, including innovative methodologies for DNA sampling, enhanced laboratory protocols for data generation, or new computer programs and statistical advances for data analyses. Thus, the aim of this editorial is to contribute to producing good quality DNA data-derived essential biodiversity variables (EBVs) (Kissling et al., 2018) by providing guidance to the community submitting articles on the subject. For that purpose, we have summarized best practices established in published literature related to the different phases involved in the process, namely sampling, laboratory work, bioinformatic analyses and data interpretation (Figure 2).
Rodríguez-Ezpeleta, Naiara; Zinger, Lucie; Kinziger, Andrew; Bik, Holly M.; Bonin, Aurélie; Coissac, Eric; Emerson, Brent C. ; Martins Lopes, Carla; Pelletier, Tara A.; Taberlet, Pierre; Narum, Shawn
FLTX2: A Novel Tamoxifen Derivative Endowed with Antiestrogenic, Fluorescent, and Photosensitizer Properties
Tamoxifen is the most widely used selective modulator of estrogen receptors (SERM) and the first strategy as coadjuvant therapy for the treatment of estrogen-receptor (ER) positive breast cancer worldwide. In spite of such success, tamoxifen is not devoid of undesirable effects, the most life-threatening reported so far affecting uterine tissues. Indeed, tamoxifen treatment is discouraged in women under risk of uterine cancers. Recent molecular design efforts have endeavoured the development of tamoxifen derivatives with antiestrogen properties but lacking agonistic uterine tropism. One of this is FLTX2, formed by the covalent binding of tamoxifen as ER binding core, 7-nitrobenzofurazan (NBD) as the florescent dye, and Rose Bengal (RB) as source for reactive oxygen species. Our analyses demonstrate (1) FLTX2 is endowed with similar antiestrogen potency as tamoxifen and its predecessor FLTX1, (2) shows a strong absorption in the blue spectral range, associated to the NBD moiety, which efficiently transfers the excitation energy to RB through intramolecular FRET mechanism, (3) generates superoxide anions in a concentration- and irradiation time-dependent process, and (4) Induces concentration- and time-dependent MCF7 apoptotic cell death. These properties make FLTX2 a very promising candidate to lead a novel generation of SERMs with the endogenous capacity to promote breast tumour cell death in situ by photosensitization.
Díaz, Mario; Lobo, Fernando; Hernández, Dácil; Amesty, Ángel; Valdés-Baizabal, Catalina; Canerina-Amaro, Ana; Mesa-Herrera, Fátima; Soler, Kevin; Boto, Alicia; Marín, Raquel; Estévez-Braun, Ana; Lahoz, Fernando
Diet of the black rat (Rattus rattus) in a Canary laurel forest: species identification based on morphological markers and DNA sequences
The black rat (Rattus rattus) is an alien species that causes severe 10 impact on island ecosystems, floras and faunas. The main aim of this study was to determine the plant and animal contributions to black rat diet in a pristine misty laurel forest area on La Palma (Canary Islands). Our working hypothesis was that this rat equally consumes plants and animals (fully omnivorous animal) wherever it is intro- 15 duced, including pristine habitats. A total of 483 droppings collected from the terrain were first morphologically examined using a stereomicroscope, which showed high plant consumption (presence in 92.4% of droppings), followed by invertebrates (46.0%) and vertebrates (31.2%). DNA-based analyses revealed even higher pro- 20 portions of plants (97%) and invertebrates (79%), while fine-scale sequence searches (DNA barcoding) in the GenBank (BLAST tool) provided a preliminary identification of 44 plants and 12 invertebrate taxa. To gain more in-depth insight into plant identification, we built up a local DNA reference collection (58 species), improving accuracy 25 (30 species confirmed) compared to GenBank searches (25 species). Contingency analyses (chisquare and G-test) only showed significant differences in droppings between plant sequences and toxic plant presence. This study confirms that the black rat is here an omnivorous animal but with a strong plant diet component, including an intrigu- 30 ingly high number of toxic plants. Interestingly, despite rodents chewing on fruits and usually crushing seeds, 66 intact Rubus seeds (Rosaceae) were found in 15 droppings (3.1%). All these results suggest that black rats consume any plant types, including fruits and seeds that can be locally dispersed such as native brambles.
Pomeda-Gutiérrez, Fernando; Medina, Félix M.; Nogales, Manuel; Vargas, Pablo