Browsing by Author "Gavaia, Paulo J."
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- Characterization of osteocalcin (BGP) and matrix gla protein (MGP) fish specific antibodies: validation for immunodetection studies in lower vertebratesPublication . Simes, D; Williamson, M. K.; Schaff, Brian J.; Gavaia, Paulo J.; Ingleton, P. M.; Price, P. A.; Cancela, LeonorIn fish species the basic mechanisms of bone development and bone remodeling are not fully understood. The classification of bone tissue in teleosts as cellular or acellular and the presence of transitional states between bone and cartilage and the finding of different types of cartilage in teleosts not previously recognized in higher vertebrates emphasizes the need for a study on the accumulation of the Gla-containing proteins MGP and BGP at the cellular level. In the present study, polyclonal antibodies developed against BGP and MGP from A. regius (a local marine teleost fish) and against MGP from G. galeus (a Pacific Ocean shark), were tested by Western blot for their specificity against BGP and MGP from several other species of teleost fish and shark. For this purpose we extracted and purified both proteins from various marine and freshwater teleosts, identified them by N-terminal amino acid sequence analysis and confirmed the presence of gamma- carboxylation in the proteins with the use of a stain specific for Gla residues. Each antibody recognized either BGP or MGP with no cross-reaction between proteins detected. All purified fish BGPs and MGPs tested were shown to be specifically recognized, thus validating the use of these antibodies for further studies.
- Characterization of specific antibodies for fish osteocalcin and its usefulness to investigate osteocalcin tissue distribution in lower vertebrates.Publication . Simes, D; Gavaia, Paulo J.; Ortiz-Delgado, J. B.; Pinto, Jorge; Cancela, LeonorOsteocalcin (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
- Cloning and ontogenetic expression of the oligopeptide transporter PepT1 (Solute carrier family 15, member 1), in fed and starved larval Atlantic cod, Gadus morhua LPublication . Rønnestad, I.; Gavaia, Paulo J.; S B Viegas, Carla; Cancela, LeonorFunctional characteristics of marine fish larvae digestive system at the onset of exogenous feeding have long been a subject for discussion. Absorption of digested proteins in vertebrates has been shown to include transporter systems for single amino acids and small peptides.
- Co-feeding in Senegalese sole larvae with inert diet from mouth opening promotes growth at weaningPublication . Engrola, S.; Figueira, L.; Conceição, L. E. C.; Gavaia, Paulo J.; Ribeiro, Laura; Dinis, Maria TeresaThe aim of this study was to determine if sole larvae co-fed with inert diet at mouth opening would perform better than larvae fed with live prey and if such a feeding regime would produce better quality juveniles. The experiment was separated in to two phases: pelagic and benthic. In the pelagic phase, treatments consisted of the standard feeding regime (rotifer and Artemia feeding), the standard feeding regime and inert diet, and rotifer for a longer period than the standard feeding regime until larvae reached 9 days after hatching (DAH). By the end of the pelagic phase, when the postlarvae were 20 DAH, sole that were co-fed with inert diet from mouth opening, were significantly smaller in weight than postlarvae fed exclusively with live prey. Sole digestive maturation was improved by co-feeding the inert diet. Survival rates, skeletal deformities and quality evaluation were not affected by the feeding regimes. In the benthic phase, the postlarvae from standard feeding regime (pelagic phase) were separated in to two treatments: standard live Artemia metanauplii until weaning and standard frozen Artemia metanauplii until weaning. Remaining treatments were the follow up of treatments from the pelagic phase. At the end of the experiment i.e. 68 DAH, the postlarvae co-fed with inert diet from mouth opening were significantly larger than all the postlarvae from remaining feeding regimes. The results of the present study demonstrate that it is possible to offer inert diet to sole at mouth opening in a co-feeding regime and to produce better quality postlarvae. Co-fed sole were larger and had a better tail condition at the end of the weaning.
- Comparative analysis of gene expression profiles among distantly related fish species. Insight into skeletal and immunological systemsPublication . Mariani, Valentina; Viegas, C. A.; Gavaia, Paulo J.; Cancela, Leonor; Giuffra, ElisabettaThe aim of this project is to identify and characterize the polymorphism of genes relevant for the physiology of skeletal and immunological tissues, and highly conserved across fish species. To achieve this goal, the expression profiles of an ancient species relevant for caviar and fillet production(A. transmontanus) are compared to available and in progress information (Marine Genomics network of Excellence, UE) of modern Teleosts.
- Comparing skeletal development of wild and hatchery-reared Senegalese sole (Solea senegalensis, Kaup 1858): Evaluation in larval and postlarval stagesPublication . Gavaia, Paulo J.; Domingues, S.; Engrola, S.; Drake, P.; Sarasquete, C.; Dinis, Maria Teresa; Cancela, LeonorThe Senegalese sole is a marine pleuronectiform that naturally occurs in Southern Europe and Mediterranean region where it is being produced in aquaculture, in particular in Portugal and Spain. The aim of this study was to assess the quality of hatchery-reared larvae in comparison with those reared in the wild, and determine to which extension wild growing larvae are also affected by skeletal deformities. The main structures affected included those forming the axial skeleton, the caudal fin complex and both anal and dorsal fins, with the most prevalent anomalies affecting caudal vertebrae and arches. Hatchery-reared fish presented a higher incidence of deformities (79%) compared with the 19% observed in wild specimens. In wild postlarvae collected in Autumn no deformities were observed. This work clearly shows that wild Senegalese sole present less skeletal deformities than those hatchery-reared during larval stages, indicating a selective mortality of wild deformed fish and/or an effect of aquaculture-related rearing conditions in the development of skeletal deformities in sole.
- Detection and localization of osteocalcin (BGP or Bone Gla Protein) in teleosts by in situ hybridization and immunohistochemistryPublication . Gavaia, Paulo J.; Viegas, C. A.; Pinto, Jorge; Sarasquete, C.; Cancela, LeonorAlthough the presence of osteocalcin (BGP) has been known for a number years, little knowledge on the regulation of expression and tissue localization of this protein in lower vertebrate organisms. In this site we have investigated the site of BGP mRNA expression by in situ hybridization using radiolabeled riboprobes and the tissue localization of the mature protein by immunohistochemistry in the Senegal sole (Solea senegalensis), zebrafish (Danio rerio), and gilthead sea bream (Sparus aurata) using fish BGP polyclonal antibodies.
- Detection of mineralized structures in very early stages of development of Marine Teleostei using a modified Alcian blue-Alizarin red double staining technique for bone and cartilagePublication . Gavaia, Paulo J.; Sarasquete, C.; Cancela, LeonorWe have developed a procedure for staining cartilage and bone in fish larvae as small as 2 mm (notochord length), for which standard alcian blue/alizarin red procedures did not give positive and/or consistent results. Small calcified structures only 100-200 pm in length can be clearly visualized. The method is suitable for both ontogenic studies during early stages of skeletal development in most marine fishes (e.g., Sparus aurata L., Solea senegalensis Kaup), whose larvae at hatching are often only a few millimeters long and for detecting skeletal abnormalities in small larvae. This procedure can also be used for specimens that have been preserved in 1000/0 ethanol for up to two years.
- Detection of skeletal abnormalities in hatchery reared Solea senegalensis (Kaup, 1858) by a whole mount double staining techniquePublication . Gavaia, Paulo J.; Dinis, Maria Teresa; Cancela, LeonorThe 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).
- Determinism and causative factors for morphological anomalies in reared European fishesPublication . Boglione, C.; Fontagné, Stéphanie; Gavaia, Paulo J.; Gisbert, Enric; Kjorsvik, E.; Koumoundouros, Giorgos; Moren, M.; Moutou, K. A.; Witten, PaulThe presence of sublethal morphological deformities represents one of the main bottleneck of the industrial finfish hatchery production, resulting in major economic loss due to reduced growth and marketing ability of the final product, that has to be transformed (filets) or sold for fish flour. Furthermore, the elimination of deformed fishes from the productive cycle needs for periodic selections at present carried out by manual sorting. This represents an additional economic cost, and a stress for fishes.