Mostrando recursos 1 - 20 de 1.154

  1. Organellar phylogenomics of an emerging model system: Sphagnum (peatmoss)

    Shaw, A. Jonathan; Devos, Nicolas; Liu, Yang; Cox, Cymon J.; Goffinet, Bernard; Flatberg, Kjell Ivar; Shaw, Blanka
    Background and Aims Sphagnum-dominated peatlands contain approx. 30 % of the terrestrial carbon pool in the form of partially decomposed plant material (peat), and, as a consequence, Sphagnum is currently a focus of studies on biogeochemistry and control of global climate. Sphagnum species differ in ecologically important traits that scale up to impact ecosystem function, and sequencing of the genome from selected Sphagnum species is currently under-way. As an emerging model system, these resources for Sphagnum will facilitate linking nucleotide variation to plant functional traits, and through those traits to ecosystem processes. A solid phylogenetic framework for Sphagnum is crucial...

  2. Profiling of antioxidant potential and phytoconstituents of Plantago coronopus

    Pereira, C. G.; Custódio, L.; Rodrigues, M. J.; Neng, N. R.; Nogueira, J. M. F.; Carlier, J.; Costa, Maria Clara; Varela, J.; Barreira, Luísa
    The halophyte species Plantago coronopus has several described ethnomedicinal uses, but few reported biological activities. This work carried out for the first time a comparative analysis of P. coronopus organs in terms of phenolic composition and antioxidant activity of organic and water extracts from roots, leaves and flowers. The leaves contents in selected nutrients, namely amino acids and minerals, are also described. Roots (ethyl acetate and methanol extracts) had the highest radical scavenging activity (RSA) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, while leaves (hexane extract) had higher RSA on nitric oxide radical and iron chelating ability. High performance...

  3. Matrix Gla protein repression by miR-155 promotes oncogenic signals in breast cancer MCF-7 cells

    Tiago, Daniel M.; Conceição, Natércia; Caiado, Helena; Laize, Vincent; Cancela, Leonor
    MGP is a protein that was initially associated with the inhibition of calcification in skeleton, soft tissues, and arteries, but more recently also implicated in cancer. In breast cancer, higher levels of MGP mRNA were associated with poor prognosis, but since this deregulation was never demonstrated at the protein level, we postulated the involvement of a post-transcriptional regulatory mechanism. In this work we show that MGP is significantly repressed by miR-155 in breast cancer MCF-7 cells, and concomitantly there is a stimulation of cell proliferation and cell invasiveness. This study brings new insights into the putative involvement of MGP and...

  4. Increased diversification rates follow shifts to bisexuality in liverworts

    Laenen, Benjamin; Machac, Antonin; Gradstein, S. Robbert; Shaw, Blanka; Patino, Jairo; Desamore, Aurelie; Goffinet, Bernard; Cox, Cymon J.; Shaw, A. Jonathan; Vanderpoorten, Alain
    Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts. We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best-fitting latent variable, yielding robust and conservative tests. We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification....

  5. 'Smelling' the cerebrospinal fluid: olfactory signaling molecules are expressed in and mediate chemosensory signaling from the choroid plexus

    Gonçalves, Isabel; Hubbard, Peter; Tomás, Joana; Quintela, Telma; Tavares, Gabriela; Caria, Sandra; Barreiros, Daniela; Santos, Cecília R. A.
    The olfactory-type signaling machinery has been known to be involved not only in odorant detection but also in other tissues with unsuspected sensory roles. As a barrier, the choroid plexus (CP) is an active participant in the monitoring of the cerebrospinal fluid (CSF), promptly responding to alterations in its composition. We hypothesized that olfactory signaling could be active in CP, contributing to the surveillance of the CSF composition. We determined the mRNA and protein expression of the major components of the olfactory transduction pathway in the rat CP, including odorant receptors, the olfactory G-protein (Gaolf), adenylate cyclase 3 and cyclic...

  6. Unlocking the in vitro anti-Trypanosoma cruzi activity of halophyte plants from the southern Portugal

    Oliveira, Marta; Sales Junior, Policarpo Ademar; Rodrigues, Maria João; DellaGreca, Marina; Barreira, Luísa; Fonseca Murta, Silvane Maria; Romanha, Álvaro José; Custódio, Luísa
    Objective: To evaluate the in vitro anti-Trypanosoma cruzi (T. cruzi) activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal (Algarve), and chemically characterize the most active samples.Methods: Acetone, dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T. cruzi. The most active extract was fractionated by preparative HPLC-DAD, affording 11 fractions. The most selective fraction was fully characterized by H-1 NMR.Results: From 94 samples tested, one was active, namely the root dichloromethane extract of Juncus acutus (IC50 < 20...

  7. Isolation of a euryhaline microalgal strain, Tetraselmis sp CTP4, as a robust feedstock for biodiesel production

    Pereira, Hugo; Gangadhar, Katkam N.; Schulze, Peter S. C.; Santos, Tamara; de Sousa, Carolina Bruno; Schueler, Lisa M.; Custódio, Luísa; Malcata, F. Xavier; Gouveia, Luísa; Varela, J.; Barreira, Luísa
    Bioprospecting for novel microalgal strains is key to improving the feasibility of microalgae-derived biodiesel production. Tetraselmis sp. CTP4 (Chlorophyta, Chlorodendrophyceae) was isolated using fluorescence activated cell sorting (FACS) in order to screen novel lipid-rich microalgae. CTP4 is a robust, euryhaline strain able to grow in seawater growth medium as well as in non-sterile urban wastewater. Because of its large cell size (9-22 mu m), CTP4 settles down after a six-hour sedimentation step. This leads to a medium removal efficiency of 80%, allowing a significant decrease of biomass dewatering costs. Using a two-stage system, a 3-fold increase in lipid content (up...

  8. Quantitative assessment of the regenerative and mineralogenic performances of the zebrafish caudal fin

    Cardeira, João; Gavaia, Paulo J.; Fernandez, Ignacio; Cengiz, Ibrahim Fatih; Moreira-Silva, Joana; Oliveira, Joaquim Miguel; Reis, Rui L.; Cancela, Leonor; Laizé, Vincent
    The ability of zebrafish to fully regenerate its caudal fin has been explored to better understand the mechanisms underlying de novo bone formation and to develop screening methods towards the discovery of compounds with therapeutic potential. Quantifying caudal fin regeneration largely depends on successfully measuring new tissue formation through methods that require optimization and standardization. Here, we present an improved methodology to characterize and analyse overall caudal fin and bone regeneration in adult zebrafish. First, regenerated and mineralized areas are evaluated through broad, rapid and specific chronological and morphometric analysis in alizarin red stained fins. Then, following a more refined...

  9. Can macroalgae provide promising anti-tumoral compounds? A closer look at Cystoseira tamariscifolia as a source for antioxidant and anti-hepatocarcinoma compounds

    Vizetto-Duarte, Catarina; Custódio, Luísa; Acosta, Gerardo; Lago, João H. G.; Morais, Thiago R.; de Sousa, Carolina Bruno; Gangadhar, Katkam N.; Rodrigues, Maria João; Pereira, Hugo; Lima, Raquel T.; Helena Vasconcelos, M.; Barreiro, Luísa; Rauter, Amélia P.; Albericioi, Fernando; Varela, J.
    Marine organisms are a prolific source of drug leads in a variety of therapeutic areas. In the last few years, biomedical, pharmaceutical and nutraceutical industries have shown growing interest in novel compounds from marine organisms, including macroalgae. Cystoseira is a genus of Phaeophyceae (Fucales) macroalgae known to contain bioactive compounds. Organic extracts (hexane, diethyl ether, ethyl acetate and methanol extracts) from three Cystoseira species (C. humilis, C. tamariscifolia and C. usneoides) were evaluated for their total phenolic content, radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, and antiproliferative activity against a human hepatocarcinoma cell line...

  10. The genome of the seagrass Zostera marina reveals angiosperm adaptation to the sea

    Olsen, Jeanine L.; Rouze, Pierre; Verhelst, Brain; Lin, Yao-Cheng; Bayer, Till; Collen, Jonas; Dattolo, Emanuela; De Paoli, Emanuele; Dittami, Simon; Maumus, Florian; Michel, Gurvan; Kersting, Anna; Lauritano, Chiara; Lohaus, Rolf; Topel, Mats; Tonon, Thierry; Vanneste, Kevin; Amirebrahimi, Mojgan; Brakel, Janina; Bostrom, Christoffer; Chovatia, Mansi; Grimwood, Jane; Jenkins, Jerry W.; Jueterbock, Alexander; Mraz, Amy; Stam, Wytze T.; Tice, Hope; Bornberg-Bauer, Erich; Green, Pamela J.; Pearson, Gareth A.; Procaccini, Gabriele; Duarte, Carlos M.; Schmutz, Jeremy; Reusch, Thorsten B. H.; Van de Peer, Yves
    Seagrasses colonized the sea(1) on at least three independent occasions to form the basis of one of the most productive and widespread coastal ecosystems on the planet(2). Here we report the genome of Zostera marina (L.), the first, to our knowledge, marine angiosperm to be fully sequenced. This reveals unique insights into the genomic losses and gains involved in achieving the structural and physiological adaptations required for its marine lifestyle, arguably the most severe habitat shift ever accomplished by flowering plants. Key angiosperm innovations that were lost include the entire repertoire of stomatal genes(3), genes involved in the synthesis of...

  11. Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress

    Camacho, A.; Simão, M.; Ea, H. -K.; Cohen-Solal, M.; Richette, P.; Branco, J.; Cancela, Leonor
    Objective: Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress.Design: OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery.Results:...

  12. Geographical range in liverworts: does sex really matter?

    Laenen, Benjamin; Machac, Antonin; Gradstein, S. Robbert; Shaw, Blanka; Patino, Jairo; Desamore, Aurelie; Goffinet, Bernard; Cox, Cymon J.; Shaw, Jonathan; Vanderpoorten, Alain
    AimWhy some species exhibit larger geographical ranges than others remains a fundamental, but largely unanswered, question in ecology and biogeography. In plants, a relationship between range size and mating system was proposed over a century ago and subsequently formalized in Baker's Law. Here, we take advantage of the extensive variation in sexual systems of liverworts to test the hypothesis that dioecious species compensate for limited fertilization by producing vegetative propagules more commonly than monoecious species. As spores are assumed to contribute to random long-distance dispersal, whereas vegetative propagules contribute to colony maintenance and frequent short-distance dispersal, we further test the...

  13. Species specificity of bacteria associated to the brown seaweeds lobophora (dictyotales, phaeophyceae) and their potential for induction of rapid coral bleaching in acropora muricata

    Vieira, Christophe; Engelen, Aschwin H.; Guentas, Linda; Aires, Tania; Houlbreque, Fanny; Gaubert, Julie; Serrão, Ester; De Clerck, Olivier; Payri, Claude E.
    While reef degradation is occurring worldwide, it is not uncommon to see phase shifts from coral to macroalgal dominated reefs. Numerous studies have addressed the mechanisms by which macroalgae may outcompete corals and a few recent studies highlighted the putative role of bacteria at the interface between macroalgae and corals. Some studies suggest that macroalgae may act as vectors and/or foster proliferation of microorganisms pathogenic for corals. Using a combination of high throughput sequencing, bacterial culturing, and in situ bioassays we question if the adversity of macroalgal associated bacteria to corals is mediated by specific bacterial taxa. Using Illumina sequencing,...

  14. Cheating the locals: invasive mussels steal and benefit from the cooling effect of indigenous mussels

    Lathlean, Justin A.; Seuront, Laurent; McQuaid, Christopher D.; Ng, Terence P. T.; Zardi, Gerardo I.; Nicastro, Katy R.
    The indigenous South African mussel Perna perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. perna for collective thermoregulation. We investigated whether varying densities of P. perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. perna within mixed artificial beds...

  15. Draft genome sequence of vibrio sp. strain Evh12, a bacterium retrieved from the gorgonian coral eunicella verrucosa.

    Franco, Telma; Califano, Gianmaria; Gonçalves, Ana C. S.; Cucio, Catarina; Costa, Rodrigo
    To shed light on the associations established between Vibrio species and soft corals in coastal ecosystems, we report here the draft genome sequence of Vibrio sp. strain Evh12, a bacterium that has been isolated from the gorgonian coral Eunicella verrucosa and that shows antagonistic activity against Escherichia coli.

  16. Genomic insights into aquimarina sp. strain EL33, a bacterial symbiont of the gorgonian coral eunicella labiata.

    Keller-Costa, Tina; Silva, Rúben; Lago-Leston, Asunción; Costa, Rodrigo
    To address the metabolic potential of symbiotic Aquimarina spp., we report here the genome sequence of Aquimarina sp. strain EL33, a bacterium isolated from the gorgonian coral Eunicella labiata This first-described (to our knowledge) animal-associated Aquimarina genome possesses a sophisticated repertoire of genes involved in drug/antibiotic resistance and biosynthesis.

  17. Macroalgal morphogenesis induced by waterborne compounds and bacteria in coastal seawater

    Grueneberg, Jan; Engelen, Aschwin H.; Costa, Rodrigo; Wichard, Thomas
    Axenic gametes of the marine green macroalga Ulva mutabilis Foyn (Ria Formosa, locus typicus) exhibit abnormal development into slow-growing callus-like colonies with aberrant cell walls. Under laboratory conditions, it was previously demonstrated that all defects in growth and thallus development can be completely abolished when axenic gametes are inoculated with a combination of two specific bacterial strains originally identified as Roseo-bacter sp. strain MS2 and Cytophaga sp. strain MS6. These bacteria release diffusible morphogenetic compounds (= morphogens), which act similar to cytokinin and auxin. To investigate the ecological relevance of the waterborne bacterial morphogens, seawater samples were collected in the...

  18. Transcriptional regulation of gilthead seabream bone morphogenetic protein (BMP) 2 gene by bone- and cartilage-related transcription factors

    Marques, Cátia L.; Cancela, Leonor; Laizé, Vincent
    Bone morphogenetic protein (BMP) 2 belongs to the transforming growth factor (3 (TGF(3) superfamily of cytokines and growth factors. While it plays important roles in embryo morphogenesis and organogenesis, BMP2 is also critical to bone and cartilage formation. Protein structure and function have been remarkably conserved throughout evolution and BMP2 transcription has been proposed to be tightly regulated, although few data is available. In this work we report the cloning and functional analysis of gilthead seabream BMP2 promoter. As in other vertebrates, seabream BMP2 gene has a 5' non-coding exon, a feature already present in DPP gene, the fruit fly...

  19. ZNF687 Mutations in Severe Paget Disease of Bone Associated with Giant Cell Tumor

    Divisato, Giuseppina; Formicola, Daniela; Esposito, Teresa; Merlotti, Daniela; Pazzaglia, Laura; Del Fattore, Andrea; Siris, Ethel; Orcel, Philippe; Brown, Jacques P.; Nuti, Ranuccio; Strazzullo, Pasquale; Benassi, Maria Serena; Cancela, Leonor; Michou, Laetitia; Rendina, Domenico; Gennari, Luigi; Gianfrancesco, Fernando
    Paget disease of bone (PDB) is a skeletal disorder characterized by focal abnormalities of bone remodeling, which result in enlarged and deformed bones in one or more regions of the skeleton. In some cases, the pagetic tissue undergoes neoplastic transformation, resulting in osteosarcoma and, less frequently, in giant cell tumor of bone (GCT). We performed whole-exome sequencing in a large family with 14 PDB-affected members, four of whom developed GCT at multiple pagetic skeletal sites, and we identified the c.2810C>G (p.Pro937Arg) missense mutation in the zinc finger protein 687 gene (ZNF687). The mutation precisely co-segregated with the clinical phenotype in...

  20. Genetic diversity and local connectivity in the mediterranean red gorgonian coral after mass mortality events

    Pilczynska, Joanna; Cocito, Silvia; Boavida, Joana; Serrão, Ester; Queiroga, Henrique
    Estimating the patterns of connectivity in marine taxa with planktonic dispersive stages is a challenging but crucial task because of its conservation implications. The red gorgonian Paramuricea clavata is a habitat forming species, characterized by short larval dispersal and high reproductive output, but low recruitment. In the recent past, the species was impacted by mass mortality events caused by increased water temperatures in summer. In the present study, we used 9 microsatellites to investigate the genetic structure and connectivity in the highly threatened populations from the Ligurian Sea (NW Mediterranean). No evidence for a recent bottleneck neither decreased genetic diversity...

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