Pityogenes chalcographus (Coleoptera, Scolytinae) at the southernmost borderline of Norway spruce (Picea abies) in Greece

Το φλοιοφάγο έντομο Pityogenes chalcographus L. αποτελεί ένα από τα κύρια βλαπτικά έντομα της υποοικογένειας Scolytinae, που είναι ευρέως εξαπλωμένο στην Ευρώπη. Ο κύριος ξενιστής του εντόμου είναι η ερυθρελάτη (Picea abies) ενώ επίσης μπορεί να αναπτυχθεί επι- τυχώς σε αρκετά ακόμη είδη κωνοφόρων όπως το πεύκο (Pinus sp.), το έλατο (Abies alba), η λάρικα (Larix decidua) και η ψευδοτσούγκα (Pseudotsuga douglasii). Παρά το γεγονός ότι η φυσική εξάπλωση του εντόμου συμπίπτει με αυτή του κύριου ξενιστή του, το P. chalcographus δεν έχει καταγραφεί ούτε και παγιδευτεί στο δάσος ερυθρελάτης στην Ελατιά Δρά- μας, που αποτελεί το νοτιότερο άκρο της φυσικής, αυτόχθονης εξάπλωσης της ερυθρελάτης. Στα πλαίσια της έρευνας εγκαταστάθηκαν στο δάσος της Ελατιάς πέντε φερομονικές παγίδες, οι οποίες περιείχαν την προσελκυστική ουσία chalcogran. Ο συνολικός αριθμός των φλοιοφά- γων εντόμων που συγκεντρώθηκαν μετά το πέρας της περιόδου που οι παγίδες ήταν στο πεδίο, ανήλθε σε αρκετές χιλιάδες ατόμων. Η ερυθρελάτη που αναπτύσσεται στο φυσικό δάσος της Ελατιάς βρίσκεται σε οριακό περιβάλλον όσον αφορά τις συνθήκες ανάπτυξής της, γεγονός που επιτείνεται και από την κλιματική αλλαγή, η οποία γίνεται ακόμη πιο εμφανής σε τέτοια περιβάλλοντα. Η συνδυαστική δράση αυτών των δύο παραγόντων μπορεί να καταστήσει την ερυθρελάτη ιδιαίτερα ευάλωτη στην προσβολή του P. chalcographus, γεγονός που θα μπο- ρούσε εν δυνάμει να θέσει σε κίνδυνο και τα ενδημικά είδη πεύκου της Ελλάδας, καθώς το φλοιοφάγο αυτό έντομο έχει την δυνατότητα ανάπτυξης σε μια πλειάδα ξενιστών.The six toothed bark beetle, Pityogenes chalcographus L. (Coleoptera: Scolytinae) is a widely distributed pest in Europe, infesting mainly Norway spruce (Picea abies) as well as other conifer species such as Pinus sp., Abies alba, Larix deciduas, L. sibirica and Pseudotsuga douglasii. Even though the distribution of this bark beetle coincides that of its main host tree, P. abies, the occurrence of P. chalcographus has never been recorded in the spruce forest of Elatia-Drama, Northern Greece, which is the southernmost area of the natural, autochthonous distribution of P. abies. In this study we installed five pheromone traps baited with chalcogran dispensers in the forest of Elatia. The total number of bark beetles attracted to these traps exceeded several thousands of individuals. Norway spruce trees growing in the natural forest of Elatia demonstrate low vigor, something that can be attributed to the marginal environmental conditions in concert with the effects of climate change. The combination of these factors inhibits the regular growth of spruce, rendering trees more susceptible to the attack of P. chalcographus

Still a Host of Hosts for Wolbachia: Analysis of Recent Data Suggests That 40% of Terrestrial Arthropod Species Are Infected

Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species

Integrating phylogenomics, phylogenetics, morphometrics, relative genome size and ecological niche modelling disentangles the diversification of Eurasian Euphorbia seguieriana s. l. (Euphorbiaceae)

Next generation sequencing has revolutionised biology. Restriction-associated DNA sequencing (RADseq) has primarily been used to study infraspecific relationships but has also been applied in multi-species phylogenomic analyses. In this study, we used a combination of phylogenomic (with RADseq data) and phylogenetic (with sequences of the nuclear internal transcribed spacer, ITS) methods to explore relationships within the taxonomically intricate Euphorbia seguieriana s. l., one of the most widespread Euphorbia taxa inhabiting zonal and extrazonal steppes from Iberia to Central Asia. In the inferred phylogenies the southeastern Balkan and Anatolian populations were clearly separated, supporting the distinction of E. niciciana from E. seguieriana at the species level. Within E. seguieriana, the populations from the Caucasus, Iran, and easternmost Anatolia were sister to all other populations based on RADseq, making necessary the description of a new, morphologically divergent subspecies, E. seguieriana subsp. armeniaca. Conversely, additional studies are needed to understand the status of E. seguieriana subsp. hohenackeri, which is sympatric with E. seguieriana subsp. armeniaca. Niche analyses indicated that differences in the climatic niche between E. niciciana and E. seguieriana are relatively small compared with the climatic differences between the regions over which they are distributed. Contrary to previous believes, E. niciciana and E. seguieriana are allopatric and have likely diverged during the Pleistocene in two different glacial refugia as suggested by distribution modelling. Euphorbia niciciana nowadays has a submediterranean distribution, occupying habitats that are slightly warmer, moister, and less seasonal in temperature but more seasonal in precipitation than E. seguieriana, a characteristic species of continental steppes. Using flow cytometry, we demonstrate that the relative genome sizes of E. niciciana and E. seguieriana differ significantly. Additionally, multivariate morphometric analyses of 56 morphological characters indicated clear morphological divergence of the two species. Importantly, we also provide a revised taxonomic treatment including formal nomenclatural changes, an identification key and species descriptions. Our study demonstrates that an integrative approach, combining modern phylogenomic methods with traditional phylogenetic, cytogenetic, environmental and morphological analyses can result in satisfactorily resolved relationships in intricate groups of closely related species. Finally, phylogenetic inference using ITS sequences is still a useful tool for resolving relationships among the taxa at the species level, but the phylogenomic approach based on RADseq data certainly provides better resolution both among and within species.Austrian Science Fund Tiroler Wissenschaftsfond

Assessing the impact of posture on diaphragm morphology and function using an open upright MRI system – a pilot study

PurposeThe diaphragm is the most important muscle of respiration. Disorders of the diaphragm can have a deleterious impact on respiratory function. We aimed to evaluate the use of an open-configuration upright low-field MRI system to assess diaphragm morphology and function in patients with bilateral diaphragm weakness (BDW) and chronic obstructive pulmonary disease (COPD) with hyperinflation.MethodThe study was approved by the National Research Ethics Committee, and written consent was obtained. We recruited 20 healthy adult volunteers, six subjects with BDW, and five subjects with COPD with hyperinflation. We measured their vital capacity in the upright and supine position, after which they were scanned on the 0.5 T MRI system during 10-second breath-holds at end-expiration and end-inspiration in both positions. We developed and applied image analysis methods to measure the volume under the dome, maximum excursion of hemidiaphragms, and anterior-posterior and left-right extension of the diaphragm.ResultsAll participants were able to complete the scanning protocol. The patients found scanning in the upright position more comfortable than the supine position. All differences in the supine inspiratory-expiratory parameters, excluding left-right extension, were significantly smaller in the BDW and COPD groups compared with healthy volunteers. No significant correlation was found between the postural change in diaphragm morphology and vital capacity in either group.ConclusionOur combined upright-supine MR imaging approach facilitates the assessment of the impact of posture on diaphragm morphology and function in patients with BDW and those with COPD with hyperinflation

Allele Intersection Analysis: A Novel Tool for Multi Locus Sequence Assignment in Multiply Infected Hosts

Wolbachia are wide-spread, endogenous α-Proteobacteria of arthropods and filarial nematodes. 15–75% of all insect species are infected with these endosymbionts that alter their host's reproduction to facilitate their spread. In recent years, many insect species infected with multiple Wolbachia strains have been identified. As the endosymbionts are not cultivable outside living cells, strain typing relies on molecular methods. A Multi Locus Sequence Typing (MLST) system was established for standardizing Wolbachia strain identification. However, MLST requires hosts to harbour individual and not multiple strains of supergroups without recombination. This study revisits the applicability of the current MLST protocols and introduces Allele Intersection Analysis (AIA) as a novel approach. AIA utilizes natural variations in infection patterns and allows correct strain assignment of MLST alleles in multiply infected host species without the need of artificial strain segregation. AIA identifies pairs of multiply infected individuals that share Wolbachia and differ in only one strain. In such pairs, the shared MLST sequences can be used to assign alleles to distinct strains. Furthermore, AIA is a powerful tool to detect recombination events. The underlying principle of AIA may easily be adopted for MLST approaches in other uncultivable bacterial genera that occur as multiple strain infections and the concept may find application in metagenomic high-throughput parallel sequencing projects

Reliability of multi-site UK Biobank MRI brain phenotypes for the assessment of neuropsychiatric complications of SARS-CoV-2 infection: The COVID-CNS travelling heads study.

Funder: National Institute for Health Research (NIHR)INTRODUCTION: Magnetic resonance imaging (MRI) of the brain could be a key diagnostic and research tool for understanding the neuropsychiatric complications of COVID-19. For maximum impact, multi-modal MRI protocols will be needed to measure the effects of SARS-CoV-2 infection on the brain by diverse potentially pathogenic mechanisms, and with high reliability across multiple sites and scanner manufacturers. Here we describe the development of such a protocol, based upon the UK Biobank, and its validation with a travelling heads study. A multi-modal brain MRI protocol comprising sequences for T1-weighted MRI, T2-FLAIR, diffusion MRI (dMRI), resting-state functional MRI (fMRI), susceptibility-weighted imaging (swMRI), and arterial spin labelling (ASL), was defined in close approximation to prior UK Biobank (UKB) and C-MORE protocols for Siemens 3T systems. We iteratively defined a comparable set of sequences for General Electric (GE) 3T systems. To assess multi-site feasibility and between-site variability of this protocol, N = 8 healthy participants were each scanned at 4 UK sites: 3 using Siemens PRISMA scanners (Cambridge, Liverpool, Oxford) and 1 using a GE scanner (King's College London). Over 2,000 Imaging Derived Phenotypes (IDPs), measuring both data quality and regional image properties of interest, were automatically estimated by customised UKB image processing pipelines (S2 File). Components of variance and intra-class correlations (ICCs) were estimated for each IDP by linear mixed effects models and benchmarked by comparison to repeated measurements of the same IDPs from UKB participants. Intra-class correlations for many IDPs indicated good-to-excellent between-site reliability. Considering only data from the Siemens sites, between-site reliability generally matched the high levels of test-retest reliability of the same IDPs estimated in repeated, within-site, within-subject scans from UK Biobank. Inclusion of the GE site resulted in good-to-excellent reliability for many IDPs, although there were significant between-site differences in mean and scaling, and reduced ICCs, for some classes of IDP, especially T1 contrast and some dMRI-derived measures. We also identified high reliability of quantitative susceptibility mapping (QSM) IDPs derived from swMRI images, multi-network ICA-based IDPs from resting-state fMRI, and olfactory bulb structure IDPs from T1, T2-FLAIR and dMRI data. CONCLUSION: These results give confidence that large, multi-site MRI datasets can be collected reliably at different sites across the diverse range of MRI modalities and IDPs that could be mechanistically informative in COVID brain research. We discuss limitations of the study and strategies for further harmonisation of data collected from sites using scanners supplied by different manufacturers. These acquisition and analysis protocols are now in use for MRI assessments of post-COVID patients (N = 700) as part of the ongoing COVID-CNS study

Factors Affecting Population Dynamics of Maternally Transmitted Endosymbionts in Bemisia tabaci

While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae) harbors the primary symbiont (P-symbiont) Portiera, the infection frequencies of the six secondary symbionts (S-symbionts) including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes) field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH), Rickettsia + Cardinium (RC), Hamiltonella + Cardinium (HC) and Rickettsia + Hamiltonella + Cardinium (RHC) varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci

Detection and Characterization of Wolbachia Infections in Natural Populations of Aphids: Is the Hidden Diversity Fully Unraveled?

Aphids are a serious threat to agriculture, despite being a rather small group of insects. The about 4,000 species worldwide engage in highly interesting and complex relationships with their microbial fauna. One of the key symbionts in arthropods is Wolbachia, an α-Proteobacterium implicated in many important biological processes and believed to be a potential tool for biological control. Aphids were thought not to harbour Wolbachia; however, current data suggest that its presence in aphids has been missed, probably due to the low titre of the infection and/or to the high divergence of the Wolbachia strains of aphids. The goal of the present study is to map the Wolbachia infection status of natural aphids populations, along with the characterization of the detected Wolbachia strains. Out of 425 samples from Spain, Portugal, Greece, Israel and Iran, 37 were found to be infected. Our results, based mainly on 16S rRNA gene sequencing, indicate the presence of two new Wolbachia supergroups prevailing in aphids, along with some strains belonging either to supergroup B or to supergroup A

Protein analysis and gene expression indicate differential vulnerability of Iberian fish species under a climate change scenario

Current knowledge on the biological responses of freshwater fish under projected scenarios of climate change remains limited. Here, we examine differences in the protein configuration of two endemic Iberian freshwater fish species, Squalius carolitertii and the critically endangered S. torgalensis that inhabit in the Atlantic-type northern and in the Mediterranean-type southwestern regions, respectively. We performed protein structure modeling of fourteen genes linked to protein folding, energy metabolism, circadian rhythms and immune responses. Structural differences in proteins between the two species were found for HSC70, FKBP52, HIF1α and GPB1. For S. torgalensis, besides structural differences, we found higher thermostability for two proteins (HSP90 and GBP1), which can be advantageous in a warmer environment. Additionally, we investigated how these species might respond to projected scenarios of 3° climate change warming, acidification (ΔpH = -0.4), and their combined effects. Significant changes in gene expression were observed in response to all treatments, particularly under the combined warming and acidification. While S. carolitertii presented changes in gene expression for multiple proteins related to folding (hsp90aa1, hsc70, fkbp4 and stip1), only one such gene was altered in S. torgalensis (stip1). However, S. torgalensis showed a greater capacity for energy production under both the acidification and combined scenarios by increasing cs gene expression and maintaining ldha gene expression in muscle. Overall, these findings suggest that S. torgalensis is better prepared to cope with projected climate change. Worryingly, under the simulated scenarios, disturbances to circadian rhythm and immune system genes (cry1aa, per1a and gbp1) raise concerns for the persistence of both species, highlighting the need to consider multi-stressor effects when evaluating climate change impacts upon fish. This work also highlights that assessments of the potential of endangered freshwater species to cope with environmental change are crucial to help decision-makers adopt future conservation strategies.info:eu-repo/semantics/publishedVersio