Search results for "Life Science"
showing 10 items of 15035 documents
Opportunity costs resulting from scramble competition within the choosy sex severely impair mate choosiness.
2016
12 pages; International audience; Studies on mate choice mainly focus on the evolution of signals that would maximize the probability of finding a good-quality partner. Most models of sexual selection rely on the implicit assumption that individuals can freely compare and spot the best mates in a heterogeneous population. Comparatively few studies have investigated the consequences of the mate-sampling process. Several sampling strategies have been studied from theoretical or experimental perspectives. They belong to two families of decision rules: best-of-n strategies (individuals sample n partners before choosing the best one within this pool) or threshold strategies (individuals sequenti…
Pearl grafting: tracking the biological origin of nuclei by straightforward immunological methods.
2018
9 pages; International audience; French Polynesia is renowned for the production of Tahitian black pearl. These gems are obtained by grafting a nucleus into the gonad of a receiving oyster together with a graft, i.e. a small section of mantle tissue of a donor oyster. This procedure initiates the formation of a pearl sack around the nucleus, and subsequently, the deposition of concentric layers of nacre. The nucleus plays a key-role in pearl formation and its characteristics influence markedly the quality of the final product. As it is manufactured from mollusc shells, it contains a small percentage of organics. In the present paper, we used a set of biochemical techniques to characterize a…
Cultivar- and Wood Area-Dependent Metabolomic Fingerprints of Grapevine Infected by Botryosphaeria Dieback
2020
International audience; Botryosphaeria dieback is one of the most significant grapevine trunk diseases that affects the sustainability of the vineyards and provokes economic losses. The causal agents, Botryosphaeriaceae species, live in and colonize the wood of the perennial organs causing wood necrosis. Diseased vines show foliar symptoms, chlorosis, or apoplexy, associated to a characteristic brown stripe under the bark. According to the susceptibility of the cultivars, specific proteins such as PR-proteins and other defense-related proteins are accumulated in the brown stripe compared with the healthy woody tissues. In this study, we enhanced the characterization of the brown stripe and …
Glomeromycotina: what is a species and why should we care?
2018
International audience; A workshop at the recent International Conference on Mycorrhiza was focused on species recognition in Glomeromycotina and parts of their basic biology that define species. The workshop was motivated by the paradigm-shifting evidence derived from genomic data for sex and for the lack of heterokaryosis, and by published exchanges in Science that were based on different species concepts and have led to differing views of dispersal and endemism in these fungi. Although a lively discussion ensued, there was general agreement that species recognition in the group is in need of more attention, and that many basic assumptions about the biology of these important fungi includ…
Extended winters entail long-term costs for insect offspring reared in an overwinter burrow
2018
International audience; Winter imposes an ecological challenge to animals living in colder climates, especially if these adverse conditions coincide with reproduction and offspring rearing. To overcome this challenge, some insects burrow in the soil to protect adults, larvae, or eggs from negative effects of winter. However, whether this protection is effective against any long-term consequences of changes in winter duration is unclear. Here, we investigated the long-term effects of winter length variation on eggs of the European earwig Forficula auricularia. In this insect, females construct and maintain a burrow between late autumn and spring, in which they provide extensive forms of care…
Tonoplast aquaporins facilitate lateral root emergence\ud
2016
Pôle SPE IPM UB; International audience; Aquaporins (AQPs) are water channels allowing fast and passive diffusion of water across cell membranes. It was hypothesized that AQPs contribute to cell elongation processes by allowing water influx across the plasma membrane and the tonoplast to maintain adequate turgor pressure. Here, we report that, in Arabidopsis (Arabidopsis thaliana), the highly abundant tonoplast AQP isoforms AtTIP1;1, AtTIP1;2, and AtTIP2;1 facilitate the emergence of new lateral root primordia (LRPs). The number of lateral roots was strongly reduced in the triple tip mutant, whereas the single, double, and triple tip mutants showed no or minor reduction in growth of the mai…
Plant growth promotion, metabolite production and metal tolerance of dark septate endophytes isolated from metal-polluted poplar phytomanagement sites
2016
Numerous studies address the distribution and the diversity of dark septate endophytes (DSEs) in the literature, but little is known about their ecological role and their effect on host plants, especially in metal-polluted soils. Seven DSE strains belonging to Cadophora, Leptodontidium, Phialophora and Phialocephala were isolated from roots of poplar trees from metal-polluted sites. All strains developed on a wide range of carbohydrates, including cell-wall-related compounds. The strains evenly colonized birch, eucalyptus and ryegrass roots in re-synthesis experiments. Root and shoot growth promotion was observed and was both plant and strain dependent. Two Phialophora and Leptodontidium st…
Highly contrasted population genetic structures in a host-parasite pair in the Caribbean Sea.
2017
Evolution and population genetic structure of marine species across the Caribbean Sea are shaped by two complex factors: the geological history and the present pattern of marine currents. Characterizing and comparing the genetic structures of codistributed species, such as host–parasite associations, allow discriminating the relative importance of environmental factors and life history traits that influenced gene flow and demographic events. Using microsatellite and Cytochrome Oxidase I markers, we investigated if a host–parasite pair (the heart urchin Meoma ventricosa and its parasitic pea crab Dissodactylus primitivus) exhibits comparable population genetic structures in the Caribbean Sea…
Functional characterization of the chaperon-like protein Cdc48 in cryptogein-induced immune response in tobacco
2017
SPEIPMUBINRASUPDATDOCT; Cdc48, a molecular chaperone conserved in different kingdoms, is a member of the AAA+ family contributing to numerous processes in mammals including proteins quality control and degradation, vesicular trafficking, autophagy and immunity. The functions of Cdc48 plant orthologues are less understood. We previously reported that Cdc48 is regulated by S-nitrosylation in tobacco cells undergoing an immune response triggered by cryptogein, an elicitin produced by the oomycete Phytophthora cryptogea. Here, we inv estigated the function of NtCdc48 in cryptogein signalling and induced hypersensitive-like cell death. NtCdc48 was found to accumulate in elicited cells at both th…
Molecular signatures of silencing suppression degeneracy from a complex RNA virus
2021
As genomic architectures become more complex, they begin to accumulate degenerate and redundant elements. However, analyses of the molecular mechanisms underlying these genetic architecture features remain scarce, especially in compact but sufficiently complex genomes. In the present study, we followed a proteomic approach together with a computational network analysis to reveal molecular signatures of protein function degeneracy from a plant virus (as virus-host protein-protein interactions). We employed affinity purification coupled to mass spectrometry to detect several host factors interacting with two proteins of Citrus tristeza virus (p20 and p25) that are known to function as RNA sil…