German Institute for Integrative Biodiversity Research iDiv

Leipzig, Germany

German Institute for Integrative Biodiversity Research iDiv

Leipzig, Germany
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Kurze C.,Martin Luther University of Halle Wittenberg | Le Conte Y.,French National Institute for Agricultural Research | Dussaubat C.,French National Institute for Agricultural Research | Erler S.,Martin Luther University of Halle Wittenberg | And 7 more authors.
PLoS ONE | Year: 2015

Apoptosis is not only pivotal for development, but also for pathogen defence in multicellular organisms. Although numerous intracellular pathogens are known to interfere with the host's apoptotic machinery to overcome this defence, its importance for host-parasite coevolution has been neglected. We conducted three inoculation experiments to investigate in the apoptotic respond during infection with the intracellular gut pathogen Nosema ceranae, which is considered as potential global threat to the honeybee (Apis mellifera) and other bee pollinators, in sensitive and tolerant honeybees. To explore apoptotic processes in the gut epithelium, we visualised apoptotic cells using TUNEL assays and measured the relative expression levels of subset of candidate genes involved in the apoptotic machinery using qPCR. Our results suggest that N. ceranae reduces apoptosis in sensitive honeybees by enhancing inhibitor of apoptosis protein-(iap)-2 gene transcription. Interestingly, this seems not be the case in Nosema tolerant honeybees. We propose that these tolerant honeybees are able to escape the manipulation of apoptosis by N. ceranae, which may have evolved a mechanism to regulate an anti-apoptotic gene as key adaptation for improved host invasion. Copyright: © 2015 Kurze et al.

Huang Q.,Martin Luther University of Halle Wittenberg | Huang Q.,Jiangxi Agricultural University | Lattorff H.M.G.,Martin Luther University of Halle Wittenberg | Lattorff H.M.G.,German Institute for Integrative Biodiversity Research IDiv | And 6 more authors.
Animal Genetics | Year: 2014

Nosema is a microsporidian parasite of the honeybee, which infects the epithelial cells of the gut. In Denmark, honeybee colonies have been selectively bred for the absence of Nosema over decades, resulting in a breeding line that is tolerant toward Nosema infections. As the tolerance toward the Nosema infection is a result of artificial selection, we screened chromosome 14 for a selective sweep with microsatellite markers, where a major quantitative trait locus (QTL) had been identified to be involved in the reduction in Nosema spores in the honeybees. By comparing the genetic variability of 10 colonies of the selected honeybee strain with a population sample from 22 unselected colonies, a selective sweep was revealed within the previously identified QTL region. The genetic variability of the swept loci was not only reduced in relation to the flanking markers on chromosome 14 within the selected strain but also significantly reduced compared with the same region in the unselected honeybees. This confirmed the results of the previous QTL mapping for reduced Nosema infections. The success of the selective breeding may have driven the selective sweep found in our study. © 2013 Stichting International Foundation for Animal Genetics.

Kurze C.,Martin Luther University of Halle Wittenberg | Mayack C.,Martin Luther University of Halle Wittenberg | Hirche F.,Martin Luther University of Halle Wittenberg | Stangl G.I.,Martin Luther University of Halle Wittenberg | And 5 more authors.
Parasitology Research | Year: 2016

Host-pathogen coevolution leads to reciprocal adaptations, allowing pathogens to increase host exploitation or hosts to minimise costs of infection. As pathogen resistance is often associated with considerable costs, tolerance may be an evolutionary alternative. Here, we examined the effect of two closely related and highly host dependent intracellular gut pathogens, Nosema apis and Nosema ceranae, on the energetic state in Nosema tolerant and sensitive honeybees facing the infection. We quantified the three major haemolymph carbohydrates fructose, glucose, and trehalose using high-performance liquid chromatography (HPLC) as a measure for host energetic state. Trehalose levels in the haemolymph were negatively associated with N. apis infection intensity and with N. ceranae infection regardless of the infection intensity in sensitive honeybees. Nevertheless, there was no such association in Nosema spp. infected tolerant honeybees. These findings suggest that energy availability in tolerant honeybees was not compromised by the infection. This result obtained at the individual level may also have implications at the colony level where workers in spite of a Nosema infection can still perform as well as healthy bees, maintaining colony efficiency and productivity. © 2016, Springer-Verlag Berlin Heidelberg.

Kurze C.,Martin Luther University of Halle Wittenberg | Routtu J.,Martin Luther University of Halle Wittenberg | Moritz R.F.A.,Martin Luther University of Halle Wittenberg | Moritz R.F.A.,German Institute for Integrative Biodiversity Research iDiv | Moritz R.F.A.,University of Pretoria
Zoology | Year: 2016

Organisms living in large groups, such as social insects, are particularly vulnerable to parasite transmission. However, they have evolved diverse defence mechanisms which are not only restricted to the individual's immune response, but also include social defences. Here, we review cases of adaptations at the individual and social level in the honeybee Apis mellifera against the ectoparasitic mite Varroa destructor and the endoparasitic microsporidians Nosema ceranae and Nosema apis. They are considered important threats to honeybee health worldwide. We highlight how individual resistance may result in tolerance at the colony level and vice versa. © 2016 Elsevier GmbH.

Erfmeier A.,Martin Luther University of Halle Wittenberg | Erfmeier A.,German Institute for Integrative Biodiversity Research iDiv
Basic and Applied Ecology | Year: 2013

Attempts to find a consensus on traits promoting the invasiveness of exotic species have agreed on the idiosyncrasy of successful invasions. Despite considerable efforts to integrate aspects of context-dependency into theories of invasions, none of them has provided an evolutionary perspective taking consistently into account the direction of environmental changes in terms of 'constraint' vs. 'release'. Applying the filter theory of species sorting, I consider different filters at different scales explaining evolutionary changes during invasions. Within this hierarchical approach, the focus is on the factorial filters climate, abiotic environment and biotic environment, distinguishing trophic interactions and plant-plant interactions. This review summarizes the evidence of adaptive shifts from native to exotic ranges, thereby differentiating the direction of shifts with regard to either constrained or released situations. Following this systematic approach, the present paper identifies further trade-offs within hierarchical levels complementing already existing hypotheses such as those for biotic interactions. In particular, the role of climatic changes should more explicitly be linked with evolutionary responses during invasions. Studying exotic species successfully invading several regions with different environmental conditions will be a promising starting point to enlarge the understanding of context-dependency of invasions. © 2013 Gesellschaft für Ökologie.

Erfmeier A.,Martin Luther University of Halle Wittenberg | Erfmeier A.,German Institute for Integrative Biodiversity Research iDiv | Hantsch L.,Martin Luther University of Halle Wittenberg | Bruelheide H.,Martin Luther University of Halle Wittenberg | Bruelheide H.,German Institute for Integrative Biodiversity Research iDiv
PLoS ONE | Year: 2013

Genetic diversity is supposed to support the colonization success of expanding species, in particular in situations where microsite availability is constrained. Addressing the role of genetic diversity in plant invasion experimentally requires its manipulation independent of propagule pressure. To assess the relative importance of these components for the invasion of Senecio vernalis, we created propagule mixtures of four levels of genotype diversity by combining seeds across remote populations, across proximate populations, within single populations and within seed families. In a first container experiment with constant Festuca rupicola density as matrix, genotype diversity was crossed with three levels of seed density. In a second experiment, we tested for effects of establishment limitation and genotype diversity by manipulating Festuca densities. Increasing genetic diversity had no effects on abundance and biomass of S. vernalis but positively affected the proportion of large individuals to small individuals. Mixtures composed from proximate populations had a significantly higher proportion of large individuals than mixtures composed from within seed families only. High propagule pressure increased emergence and establishment of S. vernalis but had no effect on individual growth performance. Establishment was favoured in containers with Festuca, but performance of surviving seedlings was higher in open soil treatments. For S. vernalis invasion, we found a shift in driving factors from density dependence to effects of genetic diversity across life stages. While initial abundance was mostly linked to the amount of seed input, genetic diversity, in contrast, affected later stages of colonization probably via sampling effects and seemed to contribute to filtering the genotypes that finally grew up. In consequence, when disentangling the mechanistic relationships of genetic diversity, seed density and microsite limitation in colonization of invasive plants, a clear differentiation between initial emergence and subsequent survival to juvenile and adult stages is required. © 2013 Erfmeier et al.

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