Search results for "RMS"
showing 10 items of 3815 documents
Rapid dissemination of Mycobacterium bovis from cattle dung to soil by the earthworm Lumbricus terrestris
2016
International audience; Indirect transmission of Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), between wildlife and livestock is thought to occur by inhalation or ingestion of environmental substrates contaminated through animal shedding. The role of the soil fauna, such as earthworms, in the circulation of M. bovis from contaminated animal feces is of interest in the epidemiology of bTB. The objective of this study was to assess the impact of earthworm activity on M. bovis transfer from animal dung to castings and the surrounding soil. For this purpose, microcosms of soil containing the anecic eathworms Lumbricus terrestris were prepared and covered with cattle fec…
Reaction norms of host immunity, host fitness and parasite performance in a mouse - intestinal nematode interaction.
2016
8 pages; International audience; The outcome of the encounter between a host and a parasite depends on the synergistic effects of the genetics of the two partners and the environment (sensulato) where the interaction takes place. Reaction norms can depict how host and parasite traits vary across environmental ranges for different genotypes. Here, we performed a large scale experiment where three strains of laboratory mice (SJL, BALB/c and CBA) were infected with four doses of the intestinal nematode Heligmosomoides polygyrus. An increasing infective dose can be considered as a proxy for the environment-dependent risk incontracting the infection. We looked at the fitness traits of hosts and …
Variation in gene expression within clones of the earthworm Dendrobaena octaedra
2017
Gene expression is highly plastic, which can help organisms to both acclimate and adapt to changing environments. Possible variation in gene expression among individuals with the same genotype (among clones) is not widely considered, even though it could impact the results of studies that focus on gene expression phenotypes, for example studies using clonal lines. We examined the extent of within and between clone variation in gene expression in the earthworm Dendrobaena octaedra, which reproduces through apomictic parthenogenesis. Five microsatellite markers were developed and used to confirm that offspring are genetic clones of their parent. After that, expression of 12 genes was measured…
Kindness to the final host and vice versa: A trend for parasites providing easy prey?
2019
Traditionally the “extended phenotype” concept refers to parasites that manipulate host phenotype to increase parasite fitness. This includes parasites that render intermediate hosts more susceptible to predation by final hosts. We explore here the proposition that an evolutionary driver in such cases is the energetic benefit to the final host, in addition to increased parasite fitness. We will review some well-established host-manipulation models, where such a scenario seems likely. One example is provided by the protozoan Toxoplasma gondii, which conspicuously impairs predator avoidance in rodents. Pathologies in humans that acquire T. gondii are known, but infection in adult feline defin…
Hemocyanin genes as indicators of habitat shifts in Panpulmonata?
2018
Hemocyanin is the primary respiratory protein for the majority of the Mollusca and therefore directly interfaces with the physiological requirements of each species and the environments to which they are adapted. Hemocyanin is therefore likely to have been evolutionarily imprinted by significant habitat shifts. In the gastropod clade Panpulmonata (>30,000 species) major realm transitions have occurred multiple times independently and may have contributed to the diversification of this group. Yet, little is known about the adaptive changes linked to these habitat shifts. In order to gain deeper insight into the evolution of panpulmonate hemocyanins and to infer possible impacts associated wi…
Reproductive strategy as a piece of the biogeographic puzzle: a case study using Antarctic sea stars (Echinodermata, Asteroidea)
2017
13 pages; International audience; AimTo describe and analyse asteroid biogeographic patterns in the Southern Ocean (SO) and test whether reproductive strategy (brooder versus broadcaster) can explain distribution patterns at the scale of the entire class. We hypothesize that brooding and broadcasting species display different biogeographic patterns.LocationSouthern Ocean, south of 45 °S.MethodsOver 14,000 asteroid occurrences are analysed using bootstrapped spanning network (BSN), non-metrical multidimensional scaling (nMDS) and clustering to uncover the spatial structure of faunal similarities among 25 bioregions.ResultsMain biogeographic patterns are congruent with previous works based on…
Differential Effect of Plant Lipids on Membrane Organization
2015
SPE IPM; International audience; The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger…
The soursop genome and comparative genomics of basal angiosperms provide new insights on evolutionary incongruence
2019
AbstractDeep relationships and the sequence of divergence among major lineages of angiosperms (magnoliids, monocots and eudicots) remain ambiguous and differ depending on analytical approaches and datasets used. Complete genomes potentially provide opportunities to resolve these uncertainties, but two recently published magnoliid genomes instead deliver further conflicting signals. To disentangle key angiosperm relationships, we report a high-quality draft genome for the soursop (Annona muricata, Annonaceae). We reconstructed phylogenomic trees and show that the soursop represents a genomic mosaic supporting different histories, with scaffolds almost exclusively supporting single topologies…
Dimensions of invasiveness: Links between local abundance, geographic range size, and habitat breadth in Europe's alien and native floras.
2021
Understanding drivers of success for alien species can inform on potential future invasions. Recent conceptual advances highlight that species may achieve invasiveness via performance along at least three distinct dimensions: 1) local abundance, 2) geographic range size, and 3) habitat breadth in naturalized distributions. Associations among these dimensions and the factors that determine success in each have yet to be assessed at large geographic scales. Here, we combine data from over one million vegetation plots covering the extent of Europe and its habitat diversity with databases on species' distributions, traits, and historical origins to provide a comprehensive assessment of invasive…
Social immunity and the evolution of group living in insects
2015
The evolution of group living requires that individuals limit the inherent risks of parasite infection. To this end, group living insects have developed a unique capability of mounting collective anti-parasite defences, such as allogrooming and corpse removal from the nest. Over the last 20 years, this phenomenon (called social immunity) was mostly studied in eusocial insects, with results emphasizing its importance in derived social systems. However, the role of social immunity in the early evolution of group living remains unclear. Here, I investigate this topic by first presenting the definitions of social immunity and discussing their applications across social systems. I then provide a…