Mostrando recursos 21 - 40 de 506

  1. Expression of Gla proteins during fish skeletal development

    Gavaia, Paulo J.
    Senegal sole skeletal development; Skeletal malformations; Skeletal malformation in mediterranean species; Senegal sole skeletal deformities; Zebra fish as model system: skeletal development; Identification of bone cells / skeletal development; Spatial - temporal pattern of bgp expression; Single cell resolution: localization of bgp mRNA; Single cell resolution: Immunolocalization of Bgp; Single cell resolution: localization of mgp mRNA; Single cell resolution: Immunolocalization of Mgp; An in vivo system to uncover MGP and BGP function; Effects of warfarin on toadfish;

  2. Whole-genome sequence analysis: evidences for new osteocalcin isoforms in fish and tetrapods

    Laizé, Vincent; Gavaia, Paulo J.; Viegas, C. S. B.; Cancela, Leonor
    The evolution of calcified tissues is a defining feature in vertebrate evolution. Investigating evolution of proteins involved in tissue calcification should help elucidate how calcified tissues have evolved. Osteocalcin (OC) is a small calcium-binding protein accumulated exclusively in bone and teeth, whose function, although essential for tissue calcification, remains unclear. Until recently, only a single osteocalcin isoform had been described (OC I).

  3. Evaluation of the skeletal quality in Senegalese sole (Solea Senegalensis, Kaup) reared under intensive vs extensive conditions

    Gavaia, Paulo J.; Richard, N.; Dâmaso, L.; Dinis, Maria Teresa; Pousão-Ferreira, P.; Engrola, S.; Conceição, L. E. C.; Cancela, Leonor
    - Senegalese sole is distributed along the Mediterranean and southwestern Europe, reaching a market price of 20-25 €/kg - Promising species for aquaculture diversification - Control and intensification of culture is reasonably achieved - The high incidence of skeletal anomalies in intensively reared fish represents a constraint to commercial production - Samples from Portugal and Greece were analyzed towards identifying skeletal differences due to rearing conditions

  4. Effect of variable levels of dietary cholesterol and plant sterols on the growth performance and bone metabolism in gilthead seabream (Sparus aurata) juveniles

    Dias, J.; Colen, Rita; Rodrigues, V.; Aragão, C.; Engrola, S.; Viegas, Michel; Laizé, Vincent; Gavaia, Paulo J.; Cancela, Leonor
    Cholesterol is found in all animal tissues and is an important component of biological cell membranes with functions such as precursor to bile acids, hormones and vitamins. Fish meal and fish oil are cholesterol-rich ingredients. Replacement of these marine-derived ingredients by plant proteins and vegetable oils tends to reduce dietary cholesterol levels.

  5. Effects of pre-weaning feeding regime on weaning performance of Senegalese sole, Solea senegalensis (Kaup, 1858)

    Engrola, S.; Conceição, L. E. C.; Gavaia, Paulo J.; Cancela, Leonor; Dinis, Maria Teresa
    Despite much interest in the production of Senegalese sole (Solea senegalensis) in southern Europe, weaning of this species onto artificial diets is problematic and varying results are obtained. The aim of this study was to test two feeding frequencies during a 13-day pre-weaning period and assess their impact on the growth and survival of Senegalese sole. Postlarvae were fed Artemia metanauplii with a peristaltic pump every hour for 12 hours per day or twice daily (morning and late afternoon). Both groups were suddenly weaned onto a commercial diet for an additional 30 days. At the end of the experiment, the relative growth rate and final dry weight...

  6. Effects of phylloquinone on Solea senegalensis skeletogenesis

    Gavaia, Paulo J.; Dionísio, G.; Conceição, L. E. C.; Hamre, K.; Cancela, Leonor
    Skeletogenesis is a continuous process occurring during fish larval development that is influenced by vitamin K VK, an essential factor for the correct formation of coagulation factors and skeletal matrix proteins. High levels of skeletal deformities are recorded in most commonly cultured species like the sparids, sea bass and flatfish like the Senegalese sole. The appearance of malformations takes place during the larval stages, when skeletal structures are forming.

  7. Diets affect skeletal development in zebrafish (Danio rerio)

    Dionísio, G.; Brito, A. B.; Cancela, Leonor; Gavaia, Paulo J.
    The zebrafish Danio rerio has recently emerged as an eminent vertebrate model for studyign genetics and development. Given the considerable importance of zebrafish as an experimental model, along with the significant economic costs associated with their large-scale use and maintenance of culturing facilities, it is to some extent surprising that their husbandry is poorly developed.

  8. Dietary lipid quality regulates bone composition and metabolism in gilthead seabream (Sparus aurata) juveniles

    Dias, J.; Rodrigues, V.; Colen, Rita; Rosa, J.; Viegas, M. N.; Cardeira, J.; Cancela, Leonor; Gavaia, Paulo J.; Laizé, Vincent
    Replacement of significant amounts of marine fish oils by vegetable oils is a major trend in the aquaculture feed industry. However, knowledge on the mechanisms underlying the nutritional regulation of bone metabolism is extremely scarce in fish. We speculate that changes in the dietary ratio of fatty acids may modulate tissue eicosanoids production and affect bone formation in fastgrowing gilthead seabream, an important fish species for aquaculture in the Mediterranean region.

  9. Developmental effects of warfin in the skeletogenesis of zebrafish (Danio rerio) larvae

    Peres dos Santos, R.; Brito, A. B.; Cancela, Leonor; Gavaia, Paulo J.
    The vitamin K-dependent gamma carboxylase (VKGC) is responsible for the post-translational modification of glutamate residues to y-carboxy glumatic acid (Gla), in the presence of the co-factor, vitamin K. This modification has important implications, such as physiological homeostasis, signal transduction and bone calcification. This mechanism ensures complete carboxylation of coagulation factors, and matrix proteins like bone Gla protein (bgp) and matrix Gla protein (mgp), being essential for their biological activity.

  10. Development of chondroid tissues in lordotic-kyphotic Senegalese sole (Solea senegalensis)

    Cardeira, J.; Mendes, A. C.; Pousão-Ferreira, P.; Cancela, Leonor; Gavaia, Paulo J.
    Vertebral deformities are frequent and constitute a major drawback for many aquaculture produced species. Lordosis and kyphosis, which are severe curvatures of the vertebral column, are particularly problematic, compromising fish marketing and profitability. Senegalese sole is a species with increasing interest in this industry and, like many others, presents high frequencies of vertebral deformities under rearing conditions.

  11. Detection of skeletal abnormalities in hatchery reared Solea senegalensis (Kaup, 1858) by a whole mount double staining technique

    Gavaia, Paulo J.; Dinis, Maria Teresa; Cancela, Leonor
    The aim of this study was to detect skeletal malformations with a bone-cartilage double staning technique in hatchery reared soles. Wild broodstock of S. senegalensis has been adapted to captivity in our facitities spawning naturally in the normal period for this species (March-July).

  12. Gene expression during regeneration of zebrafish (danio rerio) fins: relative expression levels of mineralization – related gla proteins

    Brito, A. B.; Gavaia, Paulo J.; Cancela, Leonor
    Most animals have the ability to regenerate epidermal injuries yet only a few can regenerate largely severed appendages that comprise several different tissues. Nowadays zebrafish is one of the most used metazoan models in regeneration studies in particular for investigation of molecular events during fin regeneration process. Fin regeneration starts through the formation of a blastema, a set of heterogeneous mesenchyma-like cells located between stump tissues and the wounded epidermis. This event, denominated epimorphic regeneration, comprises strict growth control and cell reprogramming leading to faithful restoration of the lost parts.

  13. Has time come for the genetic management of sea bass?

    Volckaert, F.; Alvarez, M. C.; Argenton, F.; Bonhomme, F.; Chatain, B.; Colombo, L.; Castilho, Rita; Chevassus, B.; Gorshkova, G.; Kohler, M.; Magoulas, A.; Martinez, G.; McAndrew, B. J.; Piferrer, F.; Vandeputte, M.; Zanuy, S.
    Since 1980 the industrial production of European sea bass has risen considerably up to at least 18,000 MT in 1996 ( see also Josupeit, Aquaculture Europe 20(2):-12, 1995). This growth is remarkable since few were able to culture the species in the seventies. Several "classical" stages of development can be observed; they are typical of a rapidly expanding bioindustry.

  14. Characterization of specific antibodies for fish osteocalcin and its usefulness to investigate osteocalcin tissue distribution in lower vertebrates.

    Simes, Dina; Gavaia, Paulo J.; Ortiz-Delgado, J. B.; Pinto, J. P.; Cancela, Leonor
    Osteocalcin (BGP or Bone Gla protein) is a small acidic protein with 46-50 residues (pI»4.0) that belongs to the family of the vitamin K dependent, Gla containing proteins. This protein is the most abundant non-collagenous bone protein in mammals and has been isolated only from bone and dentine suggesting that it may be expressed only in hydroxyapatite-containing bone tissue. Previous studies suggest that in mammals BGP is an ossification regulator, but its mode of action at the molecular level, in particular in non-mammalian organisms, remains unclear

  15. Proteomics as a tool to develop molecular indicators of nutritional condition in farmed gilthead seabream

    Rodrigues, Pedro; Richard, N.; De Vareilles, M.; Silva, Tomé S.; Conceição, L. E. C.
    Gilthead seabream is the main aquaculture species produced in Portugal, as well as in the Mediterranean. However, the winter disease syndrome, a series of metabolic and immune system disorders caused by low temperatures, affects seabream culture, leading to important industrial losses, either as mortalities or growth decreases during spring. These effects can be minimized through dietary optimisation, either improving diets for the end of summer season, or feeding seabream with a fortified diet during autumn/winter. However, the development of a fortified diet for autumn/winter is hindered by the lack of tools to evaluate fish metabolic and physiological condition. Nevertheless, the recent development of...

  16. Dietary tools to modulate glycogen storage in gilthead seabream muscle: glycerol supplementation

    Silva, Tomé S.; Matos, Elisabete; Cordeiro, O.; Colen, Rita; Wulff, Tune; Sampaio, Eduardo; Sousa, Vera; Valente, Luisa M. P.; Gonçalves, Amparo; Silva, Joana M. G.; Bandarra, N.; Nunes, Maria Leonor; Dinis, Maria Teresa; Dias, J.; Jessen, Flemming; Rodrigues, Pedro
    The quality and shelf life of fish meat products depend on the skeletal muscle’s energetic state at slaughter, as meat decomposition processes can be exacerbated by energy depletion. In this study, we tested dietary glycerol as a way of replenishing muscle glycogen reserves of farmed gilthead seabream. Two diets were tested in duplicate (n = 42/tank). Results show 5% inclusion of crude glycerol in gilthead seabream diets induces increased muscle glycogen, ATP levels and firmness, with no deleterious effects in terms of growth, proximate composition, fatty acid profile, oxidative state, and organoleptic properties (aroma and color). Proteomic analysis showed a low impact...

  17. Characterization of recombinant desulfovibrio gigas ferredoxin

    Rodrigues, Pedro; Graça, Fernando; Macedo, Anjos L.; Moura, Isabel; Moura, José J. G.
    Dg ferredoxin gene was cloned using the polymerase chain reaction (PCR), inserted into vector pT7-7, and overexpressed in Escherichia coli (E. coli) grown in aerobic media. The recombinant protein is a dimer and contains a [3Fe–4S] cluster per monomer. EPR and 1H NMR data of recombinant and wild-type protein are compared.

  18. Shikimate and folate pathways in the protozoan parasite, Perkinsus olseni

    Elandalloussi, Laurence M.; Rodrigues, Pedro; Afonso, Ricardo; Leite, Ricardo B.; Nunes, Patrícia A.; Cancela, Leonor
    We have exploited the experimental accessibility of the protozoan parasite Perkinsus olseni and its similarities to apicomplexan parasites to investigate the influence of specific drugs on its proliferation. For this purpose, shikimate and folate pathways present an attractive target for parasitic therapy given their major differences with mammalian pathways. Glyphosate, a potent inhibitor of the shikimate pathway enzyme EPSP synthase inhibited the in vitro proliferation of P. olseni in a dose-dependent manner and this effectwas reversed by addition of chorismate, indicating the presence of a shikimate pathway. However, this effect was not antagonised by p-aminobenzoate or folic acid. Furthermore, antagonism was...

  19. Desulfovibrio gigas ferredoxin II: redox structural modulation of the [3Fe–4S] cluster

    Rodrigues, Pedro; Macedo, Anjos L.; Goodfellow, B. J.; Moura, Isabel; Moura, José J. G.
    Desulfovibrio gigas ferredoxin II (DgFdII) is a small protein with a polypeptide chain composed of 58 amino acids, containing one Fe3S4 cluster per monomer. Upon studying the redox cycle of this protein, we detected a stable intermediate (FdIIint) with four 1H resonances at 24.1, 20.5, 20.8 and 13.7 ppm. The differences between FdIIox and FdIIint were attributed to conformational changes resulting from the breaking/formation of an internal disulfide bridge. The same 1H NMR methodology used to fully assign the three cysteinyl ligands of the [3Fe–4S] core in the oxidized state (DgFdIIox) was used here for the assignment of the same three ligands...

  20. Effect of the herbicide Roundup® on Perkinsus olseni in vitro proliferation and in vivo survival when infecting a permissive host, the Clam Ruditapes decussatus

    Elandalloussi, Laurence M.; Leite, Ricardo B.; Rodrigues, Pedro; Afonso, Ricardo; Cancela, Leonor
    Coastal habitats are increasingly being exposed to herbicide contamination from urban and agricultural catchments. Data on its toxicity on aquatic ecosystems, especially those based on sediment, are relatively scarce. This study aimed at investigating whether the susceptibility of an aquatic filter-feeding organism, the carpet-shell clam (Ruditapes decussatus) to the parasite Perkinsus olseni was influenced by the herbicide Roundup and its active ingredient glyphosate. The effect of Roundup and glyphosate on P. olseni in vitro proliferation was also evaluated and appeared to confirm the higher toxicity of Roundup when compared with technical grade glyphosate.

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