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TraceAncestor: a Tool to Infer Unphased Phylogenomic Karyotypes of Admixed Plant Genomes
No full textThe evolution of climate tolerance in conifer-feeding aphids in relation to their host's climatic niche
No full textClimate adaptation has major consequences in the evolution and ecology of all living organisms. Though phytophagous insects are an important component of Earth's biodiversity, there are few studies investigating the evolution of their climatic preferences. This lack of research is probably because their evolutionary ecology is thought to be primarily driven by their interactions with their host plants. Here, we use a robust phylogenetic framework and species-level distribution data for the conifer-feeding aphid genus Cinara to investigate the role of climatic adaptation in the diversity and distribution patterns of these host-specialized insects. Insect climate niches were reconstructed at a macroevolutionary scale, highlighting that climate niche tolerance is evolutionarily labile, with closely related species exhibiting strong climatic disparities. This result may suggest repeated climate niche differentiation during the evolutionary diversification of Cinara. Alternatively, it may merely reflect the use of host plants that occur in disparate climatic zones, and thus, in reality the aphid species' fundamental climate niches may actually be similar but broad. Comparisons of the aphids' current climate niches with those of their hosts show that most Cinara species occupy the full range of the climatic tolerance exhibited by their set of host plants, corroborating the hypothesis that the observed disparity in Cinara species' climate niches can simply mirror that of their hosts. However, 29% of the studied species only occupy a subset of their hosts' climatic zone, suggesting that some aphid species do indeed have their own climatic limitations. Our results suggest that in host-specialized phytophagous insects, host associations cannot always adequately describe insect niches and abiotic factors must be taken into account
Cytochrome P450 1A1/2, 2B6 and 3A4 HepaRG cell-based biosensors to monitor hepatocyte differentiation, drug metabolism and toxicity
No full textHuman hepatoma HepaRG cells express most drug metabolizing enzymes and constitute a pertinent in vitro alternative cell system to primary cultures of human hepatocytes in order to determine drug metabolism and evaluate the toxicity of xenobiotics. In this work, we established novel transgenic HepaRG cells transduced with lentiviruses encoding the reporter green fluorescent protein (GFP) transcriptionally regulated by promoter sequences of cytochromes P450 (CYP) 1A1/2, 2B6 and 3A4 genes. Here, we demonstrated that GFP-biosensor transgenes shared similar expression patterns with the corresponding endogenous CYP genes during proliferation and differentiation in HepaRG cells. Interestingly, differentiated hepatocyte-like HepaRG cells expressed GFP at higher levels than cholangiocyte-like cells. Despite weaker inductions of GFP expression compared to the strong increases in mRNA levels of endogenous genes, we also demonstrated that the biosensor transgenes were induced by prototypical drug inducers benzo(a)pyrene and phenobarbital. In addition, we used the differentiated biosensor HepaRG cells to evidence that pesticide mancozeb triggered selective cytotoxicity of hepatocyte-like cells. Our data demonstrate that these new biosensor HepaRG cells have potential applications in the field of chemicals safety evaluation and the assessment of drug hepatotoxicity
Taste perception of nutrients found in nutritional supplements: A review
No full textNutritional supplements are prescribed when one's nutritional status is not conducive to good health. These foodstuffs constitute concentrated sources of nutrients such as vitamins, minerals, amino acids, and fatty acids. For nutritional supplements to be effective, patients must consume the amount that has been prescribed for the recommended period of time. Therefore, special attention must be given to the sensory attributes of these products. Indeed, the presence of active compounds can cause an off-taste or aftertaste. These negative sensations can lead to a reduction in the consumption of nutritional supplements and reduce the effectiveness of the treatment. In this manuscript, we provide an overview of the sensory characteristics and the sensing receptor mechanism of the main compounds present in oral nutritional supplements, such as amino acids, minerals, fatty acids, and vitamins. Part of this article is devoted to the development of new masking strategies and the corresponding potential influence at the industrial level
AFM-Nano manipulation of plasmonic molecules used as "Nano-lens" to enhance raman of individual Nano-objects
No full textThis paper explores the enhancement of Raman signals using individual nano-plasmonic structures and demonstrates the possibility to obtain controlled gold plasmonic nanostructures by atomic force microscopy (AFM) manipulation under a confocal Raman device. By manipulating the gold nanoparticles (Nps) while monitoring them using a confocal microscope, it is possible to generate individual nano- structures, plasmonic molecules not accessible currently by lithography at these nanometer scales. This flexible approach allows us to tune plasmonic resonance of the nanostructures, to generate localized hot spots and to circumvent the effects of strong electric near field gradients intrinsic to Tip Enhanced Raman Spectroscopy (TERS) or Surface Enhanced Raman Spectroscopy (SERS) experiments. The inter Np distances and symmetry of the plasmonic molecules in interaction with other individual nano-objects control the resonance conditions of the assemblies and the enhancement of their Raman responses. This paper shows also how some plasmonic structures generate localized nanometric areas with high electric field magnitude without strong gradient. These last plasmonic molecules may be used as "nano-lenses" tunable in wavelength and able to enhance Raman signals of neighbored nano-object. The positioning of one individual probed nano-object in the spatial area defined by the nano-lens becomes then very non-restrictive, contrary to TERS experiments where the spacing distance between tip and sample is crucial. The experimental flexibility obtained in these approaches is illustrated here by the enhanced Raman scatterings of carbon nanotube
Suivi de la multi-contamination en pesticides organiques et inorganiques dans les sols viticoles : évolution des transferts sols-solution pendant une année de culture
No full textTissue-specific responses of antioxidant pathways to poor hygiene conditions in growing pigs divergently selected for feed efficiency
No full textBackground: Poor hygiene of housing induces a systemic inflammatory response. Because inflammation and oxidative stress are processes that can sustain each other, the ways pigs are able to activate their antioxidant defenses are critical for production performance and health during periods when the immune system is solicited. Selection for production performance can also influence reactive oxygen species (ROS) production and expression levels of genes involved in cellular response to oxidative stress in different tissues. To establish the extent by which poor hygiene and selection for feed efficiency affected redox status, pigs divergently selected for residual feed intake (RFI) were housed in poor or good hygiene during 6 weeks. At the end, blood was collected in all pigs, and half of them were killed for tissue sampling. The remaining pigs were reared in good hygiene conditions during a recovery period of 7-8 weeks.[br/]
Results: At week 6, poor hygiene was associated with a lower total antioxidant capacity assessed by plasma ferric reducing ability in all pigs, and with greater plasma levels of hydrogen peroxides in the high RFI pigs (less efficient). Adipose tissue of high RFI pigs exhibited higher activities of catalase and glutathione reductase, and greater thiobarbituric acid reactive substances (TBARS) concentrations when compared with the low RFI pigs (more efficient). Poor hygiene conditions activated the antioxidant enzymes activities (glutathione reductase, superoxide dismutase and catalase) in adipose tissue of both lines, but led to higher ROS production by mature adipocytes isolated from the high RFI pigs only. In liver and muscle, there were only minor changes in antioxidant molecules due to genetics and hygiene conditions. After the resilience period, adipose tissue of pigs previously challenged by poor hygiene maintained higher antioxidant enzyme activities, and for the high RFI line, displayed higher TBARS concentrations.[br/]
Conclusions: Pigs selected for improved feed efficiency showed a lower susceptibility to oxidative stress induced by poor hygiene conditions. This could led to a lower inflammatory response and less impaired growth when these pigs are facing sanitary challenges during the production period
Social intolerance is a consequence, not a cause, of dispersal in spiders.
No full textFrom invertebrates to vertebrates, a wealth of species display transient sociality during their life cycle. Investigating the causes of dispersal in temporary associations is important to better understand population dynamics. It is also essential to identify possible mechanisms involved in the evolutionary transition from transient to stable sociality, which has been documented repeatedly across taxa and typically requires the suppression of dispersal. In many animals, the onset of dispersal during ontogeny coincides with a sharp decline in social tolerance, but the causal relationship still remains poorly understood. Spiders offer relevant models to explore this question, because the adults of the vast majority of species (>48,000) are solitary and aggressive, but juveniles of most (if not all) species are gregarious and display amicable behaviors. We deployed a combination of behavioral, chemical, and modelling approaches in spiderlings of a solitary species to investigate the mechanisms controlling the developmental switch leading to the decline of social cohesion and the loss of tolerance. We show that maturation causes an increase in mobility that is sufficient to elicit dispersal without requiring any change in social behaviors. Our results further demonstrate that social isolation following dispersal triggers aggressiveness in altering the processing of conspecifics' cues. We thus provide strong evidence that aggression is a consequence, not a cause, of dispersal in spiderlings. Overall, this study highlights the need of extended social interactions to preserve tolerance, which opens new perspectives for understanding the routes to permanent sociality
