Analysis of the current risk of Leishmania infantum transmission for domestic dogs in Spain and Portugal and its future projection in climate change scenarios.

Canine leishmaniosis, caused by the protozoan parasite Leishmania infantum, is a cosmopolitan vector-borne zoonosis, transmitted principally by Phlebotomus perniciosus in Spain and Portugal, where it is considered an endemic disease. Ecoinformatics tools such as ecological niche models (ENM) have been successfully tested to model the distribution of the risk of infection of different parasitosis as they take into account environmental variables vital for their survival. The risk map proposed in this study combines the potential distribution of Ph. perniciosus in the Iberian Peninsula and the calculation of the infection rate of the parasite in the vector to model the risk of contracting the disease in a more realistic way. In fact, this weighting strategy improves the predictive power of the resulting model (R2 = 0.42, p = < 0.01) compared to the Ph. perniciosus ENM model alone (R2 = 0.13, p > 0.05). The places with the highest risk of transmission are the southwest and central peninsular area, as well as the Mediterranean coast, the Balearic Islands and the Ebro basin, places where the ideal habitat of Ph. perniciosus and the infection rate is also high. In the case of future projections under climate change scenarios, an increase in the risk of infection by L. infantum can be observed in most of the territory (4.5% in 2040, 71.6% in 2060 and 63% in 2080), mainly in the northern part of the peninsula. The use of ENMs and their weighting with the infection rate in Ph. perniciosus is a useful tool in predicting the risk of infection for L. infantum in dogs for a given area. In this way, a more complete model can be obtained to facilitate prevention and control.

Evaluating the use of non-invasive hair sampling and ddRAD to characterize populations of endangered species: Application to a peripheral population of the European mink.

The application of next-generation sequencing (NGS) to non-invasive samples is one of the most promising methods in conservation genomics, but these types of samples present significant challenges for NGS. The European mink (Mustela lutreola) is critically endangered throughout its range. However, important aspects such as census size and inbreeding remain still unknown in many populations, so it is crucial to develop new methods to monitor this species. In this work, we placed hair tubes along riverbanks in a border area of the Iberian population, which allowed the genetic identification of 76 European mink hair samples. We then applied a reduced representation genomic sequencing (ddRAD) technique to a subset of these samples to test whether we could extract sufficient genomic information from them. We show that several problems with the DNA, including contamination, fragmentation, oxidation, and possibly sample mixing, affected the samples. Using various bioinformatic techniques to reduce these problems, we were able to unambiguously genotype 19 hair samples belonging to six individuals. This small number of individuals showed that the demographic status of the species in this peripheral population is worse than expected. The data obtained also allowed us to perform preliminary analyses of relatedness and inbreeding. Although further improvements in sampling and analysis are needed, the application of the ddRAD technique to non-invasively obtained hairs represents a significant advance in the genomic study of endangered species.

Divergence time estimation using ddRAD data and an isolation-with-migration model applied to water vole populations of Arvicola.

Molecular dating methods of population splits are crucial in evolutionary biology, but they present important difficulties due to the complexity of the genealogical relationships of genes and past migrations between populations. Using the double digest restriction-site associated DNA (ddRAD) technique and an isolation-with-migration (IM) model, we studied the evolutionary history of water vole populations of the genus Arvicola, a group of complex evolution with fossorial and semi-aquatic ecotypes. To do this, we first estimated mutation rates of ddRAD loci using a phylogenetic approach. An IM model was then used to estimate split times and other relevant demographic parameters. A set of 300 ddRAD loci that included 85 calibrated loci resulted in good mixing and model convergence. The results showed that the two populations of A. scherman present in the Iberian Peninsula split 34 thousand years ago, during the last glaciation. In addition, the much greater divergence from its sister species, A. amphibius, may help to clarify the controversial taxonomy of the genus. We conclude that this approach, based on ddRAD data and an IM model, is highly useful for analyzing the origin of populations and species.

Publisher Correction: Size increase without genetic divergence in the Eurasian water shrew Neomys fodiens.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Size increase without genetic divergence in the Eurasian water shrew Neomys fodiens.

When a population shows a marked morphological change, it is important to know whether that population is genetically distinct; if it is not, the novel trait could correspond to an adaptation that might be of great ecological interest. Here, we studied a subspecies of water shrew, Neomys fodiens niethammeri, which is found in a narrow strip of the northern Iberian Peninsula. This subspecies presents an abrupt increase in skull size when compared to the rest of the Eurasian population, which has led to the suggestion that it is actually a different species. Skulls obtained from owl pellets collected over the last 50 years allowed us to perform a morphometric analysis in addition to an extensive multilocus analysis based on short intron fragments successfully amplified from these degraded samples. Interestingly, no genetic divergence was detected using either mitochondrial or nuclear data. Additionally, an allele frequency analysis revealed no significant genetic differentiation. The absence of genetic divergence and differentiation revealed here indicate that the large form of N. fodiens does not correspond to a different species and instead represents an extreme case of size increase, of possible adaptive value, which deserves further investigation.

A pipeline for metabarcoding and diet analysis from fecal samples developed for a small semi-aquatic mammal.

Metabarcoding allows the genetic analysis of pooled samples of various sources. It is becoming popular in the study of animal diet, especially because it allows the analysis of the composition of feces without the need of handling animals. In this work, we studied the diet of the Pyrenean desman (Galemys pyrenaicus), a small semi-aquatic mammal endemic to the Iberian Peninsula and the Pyrenees, by sequencing COI minibarcodes from feces using next-generation sequencing techniques. For the identification of assembled sequences, we employed a tree-based identification method that used a reference tree of sequences of freshwater organisms. The comparison of freshly collected fecal samples and older samples showed that fresh samples produced significantly more sequencing reads. They also rendered more operational taxonomical units (OTUs), but not significantly. Our analyses of 41 samples identified 224 OTUs corresponding to species of the reference tree. Ephemeroptera, Diptera excl. Chironomidae, and Chironomidae were the most highly represented groups in terms of reads as well as samples. Other groups of freshwater organisms detected were Plecoptera, Trichoptera, Neuropteroida, Coleoptera, Crustacea, and Annelida. Our results are largely in line with previous morphological and genetic studies on the diet of the Pyrenean desman, but allowed the identification of a higher diversity of OTUs in each sample. Additionally, the bioinformatic pipeline we developed for deep sequencing of fecal samples will enable the quantitative analysis of the diet of this and other species, which can be highly useful to determine their ecological requirements.

Radiofrequency radiation injures trees around mobile phone base stations.

In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50µW/m2) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact that damage afflicted on trees by mobile phone towers usually start on one side, extending to the whole tree over time.