Mitochondrial Genome Evolution in Annelida-A Systematic Study on Conservative and Variable Gene Orders and the Factors Influencing its Evolution.

The mitochondrial genomes of Bilateria are relatively conserved in their protein-coding, rRNA, and tRNA gene complement, but the order of these genes can range from very conserved to very variable depending on the taxon. The supposedly conserved gene order of Annelida has been used to support the placement of some taxa within Annelida. Recently, authors have cast doubts on the conserved nature of the annelid gene order. Various factors may influence gene order variability including, among others, increased substitution rates, base composition differences, structure of noncoding regions, parasitism, living in extreme habitats, short generation times, and biomineralization. However, these analyses were neither done systematically nor based on well-established reference trees. Several focused on only a few of these factors and biological factors were usually explored ad-hoc without rigorous testing or correlation analyses. Herein, we investigated the variability and evolution of the annelid gene order and the factors that potentially influenced its evolution, using a comprehensive and systematic approach. The analyses were based on 170 genomes, including 33 previously unrepresented species. Our analyses included 706 different molecular properties, 20 life-history and ecological traits, and a reference tree corresponding to recent improvements concerning the annelid tree. The results showed that the gene order with and without tRNAs is generally conserved. However, individual taxa exhibit higher degrees of variability. None of the analyzed life-history and ecological traits explained the observed variability across mitochondrial gene orders. In contrast, the combination and interaction of the best-predicting factors for substitution rate and base composition explained up to 30% of the observed variability. Accordingly, correlation analyses of different molecular properties of the mitochondrial genomes showed an intricate network of direct and indirect correlations between the different molecular factors. Hence, gene order evolution seems to be driven by molecular evolutionary aspects rather than by life history or ecology. On the other hand, variability of the gene order does not predict if a taxon is difficult to place in molecular phylogenetic reconstructions using sequence data or not. We also discuss the molecular properties of annelid mitochondrial genomes considering canonical views on gene evolution and potential reasons why the canonical views do not always fit to the observed patterns without making some adjustments. [Annelida; compositional biases; ecology; gene order; life history; macroevolution; mitochondrial genomes; substitution rates.].

The association between haemosporidian infection and non-breeding moult location in great reed warblers revisited by combining feather stable isotope profiles and geolocator data.

Stable isotope analysis provides valuable insights into the ecology of long-distance migratory birds during periods spent away from a specific study site. In a previous study, Swedish great reed warblers (Acrocephalus arundinaceus) infected with haemosporidian parasites differed in feather isotope ratios compared to non-infected birds, suggesting that infected and non-infected birds spent the non-breeding season in different locations or habitats. Here, we use a novel dataset comprising geolocator data, isotopes, and haemosporidian infection status of 92 individuals from four Eurasian populations to investigate whether parasite transmission varies with geography or habitats. We found that the probability of harbouring Plasmodium and Leucocytozoon parasites was higher in birds moulting in the eastern region of the non-breeding grounds. However, no geographic pattern occurred for Haemoproteus infections or overall infection status. In contrast to the previous study, we did not find any relationship between feather isotope ratios and overall haemosporidian infection for the entire current dataset. Plasmodium-infected birds had lower feather δ15N values indicating that they occupied more mesic habitats. Leucocytozoon-infected birds had higher feather δ34S values suggesting more coastal sites or wetlands with anoxic sulphate reduction. As the composition and prevalence of haemosporidian parasites differed between the old and the current dataset, we suggest that the differences might be a consequence of temporal dynamics of haemosporidian parasites. Our results emphasize the importance of replicating studies conducted on a single population over a restricted time period, as the patterns can become more complex for data from wider geographical areas and different time periods.

Dispersal modes affect Rhamnaceae diversification rates in a differentiated manner.

The evolution of dispersal modes has been proposed to promote the diversification of angiosperms. However, little is known about the relative impact of different dispersal modes on plant diversification. We test the association between dispersal modes and diversification rates using Rhamnaceae, the cosmopolitan buckthorn family, as a model. We found that species with diplochory have the highest diversification rates followed by those with myrmecochory and ballistic dispersal, while lineages dispersed by vertebrates and wind have relatively low diversification rates. The difference in diversification rates may be closely linked to the difference in dispersal distance and ecological interactions implied by each dispersal mode. Species which disperse over larger geographical distances may have much higher speciation rates due to the increased chance of establishing isolated populations due to geological barriers or habitat fragmentation. However, long-distance dispersal may also increase the chance of extinction. By contrast, species with short-distance dispersal modes may have low speciation rates. Complex interactions with the surrounding environment may, however, impact diversification rates positively by increasing plant survival and reproductive success.

Multiple paths toward repeated phenotypic evolution in the spiny-leg adaptive radiation (Tetragnatha; Hawai'i).

The repeated evolution of phenotypes provides clear evidence for the role of natural selection in driving evolutionary change. However, the evolutionary origin of repeated phenotypes can be difficult to disentangle as it can arise from a combination of factors such as gene flow, shared ancestral polymorphisms or mutation. Here, we investigate the presence of these evolutionary processes in the Hawaiian spiny-leg Tetragnatha adaptive radiation, which includes four microhabitat-specialists or ecomorphs, with different body pigmentation and size (Green, Large Brown, Maroon, and Small Brown). We investigated the evolutionary history of this radiation using 76 newly generated low-coverage, whole-genome resequenced samples, along with phylogenetic and population genomic tools. Considering the Green ecomorph as the ancestral state, our results suggest that the Green ecomorph likely re-evolved once, the Large Brown and Maroon ecomorphs evolved twice and the Small Brown evolved three times. We found that the evolution of the Maroon and Small Brown ecomorphs likely involved ancestral hybridization events, while the Green and Large Brown ecomorphs likely evolved through novel mutations, despite a high rate of incomplete lineage sorting in the dataset. Our findings demonstrate that the repeated evolution of ecomorphs in the Hawaiian spiny-leg Tetragnatha is influenced by multiple evolutionary processes.

A molecular phylogeny of the European nesticid spiders (Nesticidae, Araneae): Implications for their systematics and biogeography.

Nesticidae is a small family of spiders with a worldwide distribution that includes 15 genera and 272 described species. Seven genera and 56 species are known from Europe, distributed from the Iberian Peninsula to the Caucasus and the Ural Mountains. Most of these European species are cave dwellers and many of them are troglobites. In this study we present the first molecular phylogeny of the family Nesticidae in Europe with a wide geographical sampling across the continent. In our analysis the European nesticid fauna is well represented, including six genera and 40 of the 56 currently accepted species including the type species of all sampled genera. We have included in the analysis representatives of the North American and Asian fauna to test the monophyly of the European species and the phylogenetic relationships of European lineages. Phylogenetic relationships were reconstructed using maximum likelihood and Bayesian inference. As part of our Bayesian analyses, we also dated the phylogeny using two approaches, one based only on fossil calibrations and one that included an additional biogeographical constraint. Our results show paraphyly of the European nesticids with respect to the Asian and North American taxa. We recover four main lineages within Europe. These four European lineages and all European genera have 100% bootstrap support and high posterior probability support in the BEAST2 analysis. The Typhlonesticus lineage is the earliest branching clade present in Europe and includes seven species, the five currently accepted species plus T. parvus from Bosnia and Herzegovina and T. silvestrii from western North America. The Eastern lineage includes the genus Aituaria and is the sister group of the Asian genera Nesticella and Wraios. The Domitius lineage is likely the sister group of the Central European lineage and spreads over the Iberian and Italian peninsulas. Finally, the Central European lineage includes three genera: Kryptonesticus, distributed from the karstic massifs of the Balkan Peninsula to Turkey, Nesticus with a single synanthropic species N. cellulanus and Carpathonesticus, exclusive to the Carpathian Mountains. With the exception of the genus Typhlonesticus, all European genera show an allopatric distribution (except for the two European synanthropic species). The results obtained in this study together with the revision of the original descriptions, redescriptions, and illustrations, lead us to propose 11 nomenclatural changes (new combinations) concerning the genera Typhlonesticus, Nesticus and Carpathonesticus.

Relationships Between Soil Microbial Diversities Across an Aridity Gradient in Temperate Grasslands : Soil Microbial Diversity Relationships.

Soil microbes assemble in highly complex and diverse microbial communities, and microbial diversity patterns and their drivers have been studied extensively. However, diversity correlations and co-occurrence patterns between bacterial, fungal, and archaeal domains and between microbial functional groups in arid regions remain poorly understood. Here we assessed the relationships between the diversity and abundance of bacteria, fungi, and archaea and explored how environmental factors influence these relationships. We sampled soil along a 1500-km-long aridity gradient in temperate grasslands of Inner Mongolia (China) and sequenced the 16S rRNA gene of bacteria and archaea and the ITS2 gene of fungi. The diversity correlations and co-occurrence patterns between bacterial, fungal, and archaeal domains and between different microbial functional groups were evaluated using α-diversity and co-occurrence networks based on microbial abundance. Our results indicate insignificant correlations among the diversity patterns of bacterial, fungal, and archaeal domains using α-diversity but mostly positive correlations among diversity patterns of microbial functional groups based on α-diversity and co-occurrence networks along the aridity gradient. These results suggest that studying microbial diversity patterns from the perspective of functional groups and co-occurrence networks can provide additional insights on patterns that cannot be accessed using only overall microbial α-diversity. Increase in aridity weakens the diversity correlations between bacteria and fungi and between bacterial and archaeal functional groups, but strengthens the positive diversity correlations between bacterial functional groups and between fungal functional groups and the negative diversity correlations between bacterial and fungal functional groups. These variations of the diversity correlations are associated with the different responses of microbes to environmental factors, especially aridity. Our findings demonstrate the complex responses of microbial community structure to environmental conditions (especially aridity) and suggest that understanding diversity correlations and co-occurrence patterns between soil microbial groups is essential for predicting changes in microbial communities under future climate change in arid regions.

First evidence for development of Plasmodium relictum (Grassi and Feletti, 1891) sporozoites in the salivary glands of Culex modestus Ficalbi, 1889.

The competence of insect vectors to transmit diseases plays a key role in host-parasite interactions and in the dynamics of avian malaria and other haemosporidian infections (Apicomplexa, Haemosporida). However, the presence of parasite DNA in the body of blood-sucking insects does not always constitute evidence for their competence as vectors. In this study, we investigate the susceptibility of wild-caught mosquitoes (Culex spp.) to complete sporogony of Plasmodium relictum (cyt b lineage SGS1) isolated from great tits (Parus major L., 1758). Adult female mosquitoes were collected with a CO2 bait trap overnight. A set of 50 mosquitoes was allowed to feed for 3 h at night on a single great tit infected with P. relictum. This trial was repeated on 6 different birds. The bloodfed mosquitoes that survived (n = 68) were dissected within 1-2 days (for ookinetes, n = 10) and 10-33 days post infection (for oocysts and sporozoites, n = 58) in order to confirm the respective parasite stages in their organs. The experiment confirmed the successful development of P. relictum (cyt b lineage SGS1) to the stage of sporozoites in Culex pipiens L., 1758 (n = 27) and in Culex modestus (n = 2). Our study provides the first evidence that C. modestus is a competent vector of P. relictum isolated from great tits, suggesting that this mosquito species could also play a role in the natural transmission of avian malaria.

Interrogating Genomic-Scale Data to Resolve Recalcitrant Nodes in the Spider Tree of Life.

Genome-scale data sets are converging on robust, stable phylogenetic hypotheses for many lineages; however, some nodes have shown disagreement across classes of data. We use spiders (Araneae) as a system to identify the causes of incongruence in phylogenetic signal between three classes of data: exons (as in phylotranscriptomics), noncoding regions (included in ultraconserved elements [UCE] analyses), and a combination of both (as in UCE analyses). Gene orthologs, coded as amino acids and nucleotides (with and without third codon positions), were generated by querying published transcriptomes for UCEs, recovering 1,931 UCE loci (codingUCEs). We expected that congeners represented in the codingUCE and UCEs data would form clades in the presence of phylogenetic signal. Noncoding regions derived from UCE sequences were recovered to test the stability of relationships. Phylogenetic relationships resulting from all analyses were largely congruent. All nucleotide data sets from transcriptomes, UCEs, or a combination of both recovered similar topologies in contrast with results from transcriptomes analyzed as amino acids. Most relationships inferred from low-occupancy data sets, containing several hundreds of loci, were congruent across Araneae, as opposed to high occupancy data matrices with fewer loci, which showed more variation. Furthermore, we found that low-occupancy data sets analyzed as nucleotides (as is typical of UCE data sets) can result in more congruent relationships than high occupancy data sets analyzed as amino acids (as in phylotranscriptomics). Thus, omitting data, through amino acid translation or via retention of only high occupancy loci, may have a deleterious effect in phylogenetic reconstruction.

Phytogeographic History of the Tea Family Inferred Through High-Resolution Phylogeny and Fossils.

The tea family (Theaceae) has a highly unusual amphi-Pacific disjunct distribution: most extant species in the family are restricted to subtropical evergreen broadleaf forests in East Asia, while a handful of species occur exclusively in the subtropical and tropical Americas. Here, we used an approach that integrates the rich fossil evidence of this group with phylogenies in biogeographic analysis to study the processes behind this distribution pattern. We first combined genome-skimming sequencing with existing molecular data to build a robust species-level phylogeny for c.130 Theaceae species, resolving most important unclarified relationships. We then developed an empirical Bayesian method to incorporate distribution evidence from fossil specimens into historical biogeographic analyses and used this method to account for the spatiotemporal history of Theaceae fossils. We compared our method with an alternative Bayesian approach and show that it provides consistent results while significantly reduces computational demands which allows analyses of much larger data sets. Our analyses revealed a circumboreal distribution of the family from the early Cenozoic to the Miocene and inferred repeated expansions and retractions of the modeled distribution in the Northern Hemisphere, suggesting that the current Theaceae distribution could be the remnant of a larger continuous distribution associated with the boreotropical forest that has been hypothesized to occupy most of the northern latitudes in the early Cenozoic. These results contradict with studies that only considered current species distributions and showcase the necessity of integrating fossil and molecular data in phylogeny-based parametric biogeographic models to improve the reliability of inferred biogeographical events. [Biogeography; genome skimming; phylogenomics; plastid genome; Theaceae.].

Spider Diversification Through Space and Time.

Spiders (Araneae) make up a remarkably diverse lineage of predators that have successfully colonized most terrestrial ecosystems. All spiders produce silk, and many species use it to build capture webs with an extraordinary diversity of forms. Spider diversity is distributed in a highly uneven fashion across lineages. This strong imbalance in species richness has led to several causal hypotheses, such as codiversification with insects, key innovations in silk structure and web architecture, and loss of foraging webs. Recent advances in spider phylogenetics have allowed testing of some of these hypotheses, but results are often contradictory, highlighting the need to consider additional drivers of spider diversification. The spatial and historical patterns of diversity and diversification remain contentious. Comparative analyses of spider diversification will advance only if we continue to make progress with studies of species diversity, distribution, and phenotypic traits, together with finer-scale phylogenies and genomic data.

Global distribution and evolutionary transitions of angiosperm sexual systems.

Angiosperm sexual systems are fundamental to the evolution and distribution of plant diversity, yet spatiotemporal patterns in angiosperm sexual systems and their drivers remain poorly known. Using data on sexual systems and distributions of 68453 angiosperm species, we present the first global maps of sexual system frequencies and evaluate sexual system evolution during the Cenozoic. Frequencies of dioecy and monoecy increase with latitude, while hermaphrodites are more frequent in warm and arid regions. Transitions to dioecy from other states were higher than to hermaphroditism, but transitions away from dioecy increased since the Cenozoic, suggesting that dioecy is not an evolutionary end point. Transitions between hermaphroditism and dioecy increased, while transitions to monoecy decreased with paleo-temperature when paleo-temperature >0℃. Our study demonstrates the biogeography of angiosperm sexual systems from a macroecological perspective, and enhances our understanding of plant diversity patterns and their response to climate change.

Monophyly, Taxon Sampling, and the Nature of Ranks in the Classification of Orb-Weaving Spiders (Araneae: Araneoidea).

We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019).

Converging on the orb: denser taxon sampling elucidates spider phylogeny and new analytical methods support repeated evolution of the orb web.

High throughput sequencing and phylogenomic analyses focusing on relationships among spiders have both reinforced and upturned long-standing hypotheses. Likewise, the evolution of spider webs-perhaps their most emblematic attribute-is being understood in new ways. With a matrix including 272 spider species and close arachnid relatives, we analyze and evaluate the relationships among these lineages using a variety of orthology assessment methods, occupancy thresholds, tree inference methods and support metrics. Our analyses include families not previously sampled in transcriptomic analyses, such as Symphytognathidae, the only araneoid family absent in such prior works. We find support for the major established spider lineages, including Mygalomorphae, Araneomorphae, Synspermiata, Palpimanoidea, Araneoidea and the Retrolateral Tibial Apophysis Clade, as well as the uloborids, deinopids, oecobiids and hersiliids Grade. Resulting trees are evaluated using bootstrapping, Shimodaira-Hasegawa approximate likelihood ratio test, local posterior probabilities and concordance factors. Using structured Markov models to assess the evolution of spider webs while accounting for hierarchically nested traits, we find multiple convergent occurrences of the orb web across the spider tree-of-life. Overall, we provide the most comprehensive spider tree-of-life to date using transcriptomic data and use new methods to explore controversial issues of web evolution, including the origins and multiple losses of the orb web.

COVID-19 in Liver Transplant Recipients - Preliminary Experience of a Bulgarian Center.

Introduction: There are still debatable facts about estimating the risk and severity of coronavirus disease (COVID-19) in liver transplant recipients, as well as assessing the impact of the immunosuppressive therapy on the clinical course and incidence of liver failure. Material and Methods: We present a prospective study of liver transplant recipients with severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection admitted for treatment to the department of First Clinic of Abdominal Surgery, Military Medical Academy, Sofia during 25.11.2020 04.01.2021. The diagnosis is confirmed by a positive reverse transcription polymerase chain reaction (RT-PCR) test for SARS-CoV-2 infection from a naso-pharyngeal swab. COVID-19 severity is estimated as mild (oxygen saturation (SpO2) 94% on room air and no imaging findings of pneumonia), moderate (SpO2 94%, imaging suggestive of pneumonia), and severe (need for high flow oxygen supplementation). Results: Three liver transplant recipients with COVID-19 were admitted and treated in our department during 25.11.2020 04.01.2021. All of them were male, mean age of 51.33 years (47 - 59) and their liver transplantations were performed 13, 5, and 1.5 years before. In each of the three patients a different clinical form of the disease was registered mild (n=1), moderate (n=1), and severe (n=1). Only the patient with severe disease had comorbidities - hypertension, diabetes, and obesity. The patients with mild and moderate disease received dual immunosuppressive therapy with tacrolimus and mycophenolate mofetil while the one with severe disease - tacrolimus only. A dose reduction of tacrolimus was undertaken following serum level evaluation without changing the dose of the mycophenolate mofetil for those on dual therapy. The patient with severe disease died from respiratory failure leading to a case fatality rate of 33.3%. Conclusion: Early diagnosis and hospitalization where possible are essential for the prompt initiation of treatment, prevention of complications and development of severe forms of COVID-19 in liver transplant recipients, especially in patients with comorbidities such as hypertension, diabetes, and obesity. During the course of treatment there may be a dose reduction of the immunosuppressive therapy but not discontinuation, especially of the calcineurin inhibitor in mono- or dual-therapy regimens.

Phylogeny of the orb-weaving spider family Araneidae (Araneae: Araneoidea).

We present a new phylogeny of the spider family Araneidae based on five genes (28S, 18S, COI, H3 and 16S) for 158 taxa, identified and mainly sequenced by us. This includes 25 outgroups and 133 araneid ingroups representing the subfamilies Zygiellinae Simon, 1929, Nephilinae Simon, 1894, and the typical araneids, here informally named the "ARA Clade". The araneid genera analysed here include roughly 90% of all currently named araneid species. The ARA Clade is the primary focus of this analysis. In taxonomic terms, outgroups comprise 22 genera and 11 families, and the ingroup comprises three Zygiellinae and four Nephilinae genera, and 85 ARA Clade genera (ten new). Within the ARA Clade, we recognize ten informal groups that contain at least three genera each and are supported under Bayesian posterior probabilities (≥ 0.95): "Caerostrines" (Caerostris, Gnolus and Testudinaria), "Micrathenines" (Acacesia, Micrathena, Ocrepeira, Scoloderus and Verrucosa), "Eriophorines" (Acanthepeira, Alpaida, Eriophora, Parawixia and Wagneriana), "Backobourkiines" (Acroaspis, Backobourkia, Carepalxis, Novakiella, Parawixia, Plebs, Singa and three new genera), "Argiopines" (Arachnura, Acusilas, Argiope, Cyrtophora, Gea, Lariniaria and Mecynogea), "Cyrtarachnines" (Aranoethra, Cyrtarachne, Paraplectana, Pasilobus and Poecilopachys), "Mastophorines" (Celaenia, Exechocentrus and Mastophora,), "Nuctenines" (Larinia, Larinioides and Nuctenea), "Zealaraneines" (Colaranea, Cryptaranea, Paralarinia, Zealaranea and two new genera) and "Gasteracanthines" (Augusta, Acrosomoides, Austracantha, Gasteracantha, Isoxya, Macracantha, Madacantha, Parmatergus and Thelacantha). Few of these groups are currently corroborated by morphology, behaviour, natural history or biogeography. We also include the large genus Araneus, along with Aculepeira, Agalenatea, Anepsion, Araniella, Cercidia, Chorizopes, Cyclosa, Dolophones, Eriovixia, Eustala, Gibbaranea, Hingstepeira, Hypognatha, Kaira, Larinia, Mangora, Metazygia, Metepeira, Neoscona, Paraplectanoides, Perilla, Poltys, Pycnacantha, Spilasma and Telaprocera, but the placement of these genera was generally ambiguous, except for Paraplectanoides, which is strongly supported as sister to traditional Nephilinae. Araneus, Argiope, Eriophora and Larinia are polyphyletic, Araneus implying nine new taxa of genus rank, and Eriophora and Larinia two each. In Araneus and Eriophora, polyphyly was usually due to north temperate generic concepts being used as dumping grounds for species from southern hemisphere regions, e.g. South-East Asia, Australia or New Zealand. Although Araneidae is one of the better studied spider families, too little natural history and/or morphological data are available across these terminals to draw any strong evolutionary conclusions. However, the classical orb web is reconstructed as plesiomorphic for Araneidae, with a single loss in "cyrtarachnines"-"mastophorines". Web decorations (collectively known as stabilimenta) evolved perhaps five times. Sexual dimorphism generally results from female body size increase with few exceptions; dimorphic taxa are not monophyletic and revert to monomorphism in a few cases.

Chemometric Assessment of Soil Pollution and Pollution Source Apportionment for an Industrially Impacted Region around a Non-Ferrous Metal Smelter in Bulgaria.

The present study deals with the assessment of pollution caused by a large industrial facility using multivariate statistical methods. The primary goal is to classify specific pollution sources and to apportion their involvement in the formation of the total concentration of the chemical parameters being monitored. This aim is accomplished by intelligent data analysis based on cluster analysis, principal component analysis and principal component regression analysis. Five latent factors are found to explain over 80% of the total variance of the system being conditionally named "organic", "non-ferrous smelter", "acidic", "secondary anthropogenic contribution" and "natural" factor. The apportionment models designate the contribution of the identified sources quantitatively and help in the interpretation of risk assessment and management actions. Since the study takes into account pollution uptake from soil to a cabbage plant, the data interpretation could help in introducing biomonitoring aspects of the assessment. The chemometric expertise helps in revealing hidden relationships between the objects and the variables involved to achieve a better understanding of specific pollution events in the soil of a severely industrially impacted region.

Microhabitat change drives diversification in pholcid spiders.

BACKGROUND: Microhabitat changes are thought to be among the main drivers of diversification. However, this conclusion is mostly based on studies on vertebrates. Here, we investigate the influence of microhabitat on diversification rates in pholcid spiders (Araneae, Pholcidae). Diversification analyses were conducted in the framework of the largest molecular phylogeny of pholcid spiders to date based on three nuclear and three mitochondrial loci from 600 species representing more than 85% of the currently described pholcid genera. RESULTS: Assessments of ancestral microhabitat revealed frequent evolutionary change. In particular, within the largest subfamily Pholcinae, numerous changes from near-ground habitats towards leaves and back were found. In general, taxa occupying leaves and large sheltered spaces had higher diversification rates than ground-dwelling taxa. Shifts in speciation rate were found in leaf- and space-dwelling taxa. CONCLUSIONS: Our analyses result in one of the most comprehensive phylogenies available for a major spider family and provide a framework for any subsequent studies of pholcid spider biology. Diversification analyses strongly suggest that microhabitat is an important factor influencing diversification patterns in pholcid spiders.

Low intensity blood parasite infections do not reduce the aerobic performance of migratory birds.

Blood parasites (Haemosporidia) are thought to impair the flight performance of infected animals, and therefore, infected birds are expected to differ from their non-infected counterparts in migratory capacity. Since haemosporidians invade host erythrocytes, it is commonly assumed that infected individuals will have compromised aerobic capacity, but this has not been examined in free-living birds. We tested if haemosporidian infections affect aerobic performance by examining metabolic rates and exercise endurance in migratory great reed warblers (Acrocephalus arundinaceus) experimentally treated with Plasmodium relictum pGRW04 and in naturally infected wild birds over consecutive life-history stages. We found no effect of acute or chronic infections on resting metabolic rate, maximum metabolic rate or exercise endurance in either experimentally treated or free-living birds. Oxygen consumption rates during rest and while undergoing maximum exercise as well as exercise endurance increased from breeding to migration stages in both infected and non-infected birds. Importantly, phenotypic changes associated with preparation for migration were similarly unaffected by parasitaemia. Consequently, migratory birds experiencing parasitaemia levels typical of chronic infection do not differ in migratory capacity from their uninfected counterparts. Thus, if infected hosts differ from uninfected conspecifics in migration phenology, other mechanisms besides aerobic capacity should be considered.

Detecting local transmission of avian malaria and related haemosporidian parasites (Apicomlexa, Haemosporida) at a Special Protection Area of Natura 2000 network.

Avian haemosporidian parasites (Apicomplexa, Haemosporida) are widespread pathogens that cause malaria (Plasmodium spp.) and other haemosporidioses (Haemoproteus spp. and Leucocytozoon spp.) in birds. The Special Protection Area Durankulak Lake (SPA DL) is a coastal lake in northeast Bulgaria, part of the Natura 2000 network that was declared as important area for wintering, breeding and migratory birds. Despite a number of conservation efforts outlined for the SPAs of Natura 2000 network, the potential threats and influences of haemosporidians and other parasites on occurring birds were not considered. In the present study, we aim to investigate the richness of haemosporidian parasites in birds captured in the protected area and to report the parasite species/DNA lineages that undergo local transmission in the region. We used both microscopic examination and PCR-based methods to diagnose haemosporidian infections in juvenile (captured in the year of hatching) and adult birds. The overall prevalence of haemosporidian parasites was significantly higher in the adult birds compared to juveniles. We identified five out of 21 recorded cytochrome b (cyt b) parasite lineages that are locally transmitted in the SPA DL (one of the genus Haemoproteus Kruse, 1890 and four of genus Plasmodium Marchiafava and Celli, 1885): cyt b lineages hRW2 of Haemoproteus belopolskyi, pSGS1 of Plasmodium relictum, pCOLL1, pYWT4 and pPADOM01 of Plasmodium (Haemamoeba) spp. It is likely that the majority of the parasites with local transmission are widespread host generalists and that host exchange is rather frequent among the birds inhabiting SPA DL.

Host migration strategy and blood parasite infections of three sparrow species sympatrically breeding in Southeast Europe.

Mobile hosts like birds occupy a wide array of habitats in which they encounter various vector and parasite faunas. If the infection probability for vector-borne parasites varies among seasons and biomes, a migratory life can critically influence the infections of a host. The growing body of literature on avian blood parasites suggests that host migrations do not only influence prevalence of infection but can also evoke higher infection intensities and increased parasite diversity in migrant compared to resident host species. We investigated the prevalence, intensity and diversity of Plasmodium and Haemoproteus infections in three closely-related and sympatrically breeding sparrow species with different migration strategies ranging from residential house sparrow and partially migratory tree sparrow to the obligate migratory Spanish sparrow. With a prevalence of 49%, the migratory Spanish sparrows were significantly less frequently infected than the resident house sparrows (82%). The partially migratory tree sparrow showed an intermediate prevalence of 60%. The parasitaemias were similar in all three host species and indicated mostly chronic but also few acute infections. While we found Plasmodium parasites in all three sparrow species, only Spanish sparrows were infected with Haemoproteus parasites in our study. With nine clearly identified parasite lineages in our study and the highest number of lineages per infected individuals (i.e. relative diversity), Spanish sparrows harboured the most diverse parasite fauna. Our results suggest that migration strategies can affect Plasmodium and Haemoproteus infections of sparrows resulting in a lower parasite prevalence and higher parasite diversity in migratory hosts-at least during our host's breeding period. A general scope for all annual cycle periods and across various bird taxa remains to be elucidated.