238 research outputs found
Climate, immigration and speciation shape terrestrial and aquatic biodiversity in the European Alps
Quaternary climate fluctuations can affect speciation in regional biodiversity assembly in two non-mutually exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation in underused adaptive zones during ice-free periods. We detected biogeographic and genetic signatures associated with both mechanisms in the assembly of the biota of the European Alps. Age distributions of endemic and widespread species within aquatic and terrestrial taxa (amphipods, fishes, amphibians, butterflies and flowering plants) revealed that endemic fish evolved only in lakes, are highly sympatric, and mainly of Holocene age, consistent with adaptive radiation. Endemic amphipods are ancient, suggesting preglacial radiation with limited range expansion and local Pleistocene survival, perhaps facilitated by a groundwater-dwelling lifestyle. Terrestrial endemics are mostly of Pleistocene age and are thus more consistent with the glacial species pump. The lack of evidence for Holocene adaptive radiation in the terrestrial biome is consistent with faster recolonization through range expansion of these taxa after glacial retreats. More stable and less seasonal ecological conditions in lakes during the Holocene may also have contributed to Holocene speciation in lakes. The high proportion of young, endemic species makes the Alpine biota vulnerable to climate change, but the mechanisms and consequences of species loss will likely differ between biomes because of their distinct evolutionary histories
Climate, immigration and speciation shape terrestrial and aquatic biodiversity in the European Alps.
Quaternary climate fluctuations can affect speciation in regional biodiversity assembly in two non-mutually exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation in underused adaptive zones during ice-free periods. We detected biogeographic and genetic signatures associated with both mechanisms in the assembly of the biota of the European Alps. Age distributions of endemic and widespread species within aquatic and terrestrial taxa (amphipods, fishes, amphibians, butterflies and flowering plants) revealed that endemic fish evolved only in lakes, are highly sympatric, and mainly of Holocene age, consistent with adaptive radiation. Endemic amphipods are ancient, suggesting preglacial radiation with limited range expansion and local Pleistocene survival, perhaps facilitated by a groundwater-dwelling lifestyle. Terrestrial endemics are mostly of Pleistocene age and are thus more consistent with the glacial species pump. The lack of evidence for Holocene adaptive radiation in the terrestrial biome is consistent with faster recolonization through range expansion of these taxa after glacial retreats. More stable and less seasonal ecological conditions in lakes during the Holocene may also have contributed to Holocene speciation in lakes. The high proportion of young, endemic species makes the Alpine biota vulnerable to climate change, but the mechanisms and consequences of species loss will likely differ between biomes because of their distinct evolutionary histories
Citizen science versus professional data collection: Comparison of approaches to mosquito monitoring in Germany
Due to the recent emergence of invasive mosquito species and the outbreaks of mosquito-borne diseases in Europe, research on the ecology and diversity of the mosquito fauna has returned to scientific agendas. Through a nationwide surveillance programme in Germany, mosquitoes have been monitored actively by systematically operated traps since 2011, and passively by the 'Mückenatlas' (mosquito atlas) citizen science project launched in 2012. To assess the performance of both monitoring methods we compared the two respective datasets with regard to habitat coverage, species composition and the ability to detect invasive mosquitoes. The datasets include observations from the beginning of the project until the end of 2017. We found significant differences in species composition caused by land use types and the participants' recording activity. Active monitoring performed better in mapping mosquito diversity, whereas passive monitoring better detected invasive species, thereby using data from private premises scientists usually cannot access. Synthesis and applications. Active and passive monitoring is complementary. Combining them allows for the determination of mosquito diversity, efficient detection of emerging invasive species and the initiation of rapid-response actions against such invaders. The 'Mückenatlas' sets an example for the usefulness of citizen science when included in a national monitoring programme, an approach that may be worth copying for tackling the global spread of arthropod vectors of disease agents
Linking human impacts to community processes in terrestrial and freshwater ecosystems
Human impacts such as habitat loss, climate change and biological invasions are radically altering biodiversity, with greater effects projected into the future. Evidence suggests human impacts may differ substantially between terrestrial and freshwater ecosystems, but the reasons for these differences are poorly understood. We propose an integrative approach to explain these differences by linking impacts to four fundamental processes that structure communities: dispersal, speciation, species-level selection and ecological drift. Our goal is to provide process-based insights into why human impacts, and responses to impacts, may differ across ecosystem types using a mechanistic, eco-evolutionary comparative framework. To enable these insights, we review and synthesise (i) how the four processes influence diversity and dynamics in terrestrial versus freshwater communities, specifically whether the relative importance of each process differs among ecosystems, and (ii) the pathways by which human impacts can produce divergent responses across ecosystems, due to differences in the strength of processes among ecosystems we identify. Finally, we highlight research gaps and next steps, and discuss how this approach can provide new insights for conservation. By focusing on the processes that shape diversity in communities, we aim to mechanistically link human impacts to ongoing and future changes in ecosystems
A large multi-country outbreak of monkeypox across 41 countries in the WHO European Region, 7 March to 23 August 2022
Following the report of a non-travel-associated cluster of monkeypox cases by the United Kingdom in May 2022, 41 countries across the WHO European Region have reported 21,098 cases and two deaths by 23 August 2022. Nowcasting suggests a plateauing in case notifications. Most cases (97%) are MSM, with atypical rash-illness presentation. Spread is mainly through close contact during sexual activities. Few cases are reported among women and children. Targeted interventions of at-risk groups are needed to stop further transmission. © 2022 European Centre for Disease Prevention and Control (ECDC). All rights reserved.The authors affiliated with the World Health Organization (WHO) are alone responsible for the views expressed in this publication and they do not necessarily represent the decisions or policies of the WHO. The co-author is a fellow of the ECDC Fellowship Programme, supported financially by the European Centre for Disease Prevention and Control (ECDC). The views and opinions expressed herein do not state or reflect those of ECDC. ECDC is not responsible for the data and information collation and analysis and cannot be held liable for conclusions or opinions drawn
Contrasting responses of above- and belowground diversity to multiple components of land-use intensity
Stem cell-derived macrophages as a new platform for studying host-pathogen interactions in livestock
BACKGROUND: Infectious diseases of farmed and wild animals pose a recurrent threat to food security and human health. The macrophage, a key component of the innate immune system, is the first line of defence against many infectious agents and plays a major role in shaping the adaptive immune response. However, this phagocyte is a target and host for many pathogens. Understanding the molecular basis of interactions between macrophages and pathogens is therefore crucial for the development of effective strategies to combat important infectious diseases. RESULTS: We explored how porcine pluripotent stem cells (PSCs) can provide a limitless in vitro supply of genetically and experimentally tractable macrophages. Porcine PSC-derived macrophages (PSCdMs) exhibited molecular and functional characteristics of ex vivo primary macrophages and were productively infected by pig pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV), two of the most economically important and devastating viruses in pig farming. Moreover, porcine PSCdMs were readily amenable to genetic modification by CRISPR/Cas9 gene editing applied either in parental stem cells or directly in the macrophages by lentiviral vector transduction. CONCLUSIONS: We show that porcine PSCdMs exhibit key macrophage characteristics, including infection by a range of commercially relevant pig pathogens. In addition, genetic engineering of PSCs and PSCdMs affords new opportunities for functional analysis of macrophage biology in an important livestock species. PSCs and differentiated derivatives should therefore represent a useful and ethical experimental platform to investigate the genetic and molecular basis of host-pathogen interactions in pigs, and also have wider applications in livestock. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12915-021-01217-8
Variations in T Cell Transcription Factor Sequence and Expression Associated with Resistance to the Sheep Nematode Teladorsagia circumcincta
This study used selected lambs that varied in their resistance to the gastrointestinal parasite Teladorsagia circumcincta. Infection over 12 weeks identified susceptible (high adult worm count, AWC; high fecal egg count, FEC; low body weight, BW; low IgA) and resistant sheep (no/low AWC and FEC, high BW and high IgA). Resistance is mediated largely by a Th2 response and IgA and IgE antibodies, and is a heritable characteristic. The polarization of T cells and the development of appropriate immune responses is controlled by the master regulators, T-bet (TBX21), GATA-3 (GATA3), RORγt (RORC2) and RORα (RORA); and several inflammatory diseases of humans and mice are associated with allelic or transcript variants of these transcription factors. This study tested the hypothesis that resistance of sheep to T. circumcincta is associated with variations in the structure, sequence or expression levels of individual master regulator transcripts. We have identified and sequenced one variant of sheep TBX21, two variants of GATA3 and RORC2 and five variants of RORA from lymph node mRNA. Relative RT-qPCR analysis showed that TBX21, GATA3 and RORC2 were not significantly differentially-expressed between the nine most resistant (AWC, 0; FEC, 0) and the nine most susceptible sheep (AWC, mean 6078; FEC, mean 350). Absolute RT-qPCR on 29 all 45 animals identified RORAv5 as being significantly differentially-expressed (p = 0.038) 30 between resistant, intermediate and susceptible groups; RORAv2 was not differentially- 31 expressed (p = 0.77). Spearman’s rank analysis showed that RORAv5 transcript copy number 32 was significantly negatively correlated with parameters of susceptibility, AWC and FEC; and 33 was positively correlated with BW. RORAv2 was not correlated with AWC, FEC or BW but 34 was significantly negatively correlated with IgA antibody levels [corrected]. This study identifies the full length RORA variant (RORAv5) as important in controlling the protective immune response to T. circumcincta infection in sheep
Linking human impacts to community processes in terrestrial and freshwater ecosystems.
Human impacts such as habitat loss, climate change and biological invasions are radically altering biodiversity, with greater effects projected into the future. Evidence suggests human impacts may differ substantially between terrestrial and freshwater ecosystems, but the reasons for these differences are poorly understood. We propose an integrative approach to explain these differences by linking impacts to four fundamental processes that structure communities: dispersal, speciation, species-level selection and ecological drift. Our goal is to provide process-based insights into why human impacts, and responses to impacts, may differ across ecosystem types using a mechanistic, eco-evolutionary comparative framework. To enable these insights, we review and synthesise (i) how the four processes influence diversity and dynamics in terrestrial versus freshwater communities, specifically whether the relative importance of each process differs among ecosystems, and (ii) the pathways by which human impacts can produce divergent responses across ecosystems, due to differences in the strength of processes among ecosystems we identify. Finally, we highlight research gaps and next steps, and discuss how this approach can provide new insights for conservation. By focusing on the processes that shape diversity in communities, we aim to mechanistically link human impacts to ongoing and future changes in ecosystems
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