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- Programming the metabolic gene expression in zebrafish juveniles (Danio rerio) by supra-physiological glucose level during embryogenesisPublication . Rocha, F.; Dias, J.; Engrola, S.; Gavaia, Paulo J.; Geurden, Inge; Dinis, Maria Teresa; Panserat, S.Using zebrafish as a model organism, assess the effect of high glucose levels during early embryonic stages as a lifelong moderator of metabolic pathways.
- Identificação de Malformações Esqueléticas em PeixesPublication . Gavaia, Paulo J.- Monitorizar e identificar as principais malformações que ocorrem em peixes produzidos em aquacultura intensiva. Desenvolver estudos em conjunto com empresas da região para relacionar (1) condições de cultivo (em particular factores nutricionais) e desenvolvimento esquelético, (2) relações genéticas entre reprodutores e progenia e tentar identificar possíveis causas genéticas para presença de larvas com deformações esqueléticas.
- Molecular insights indicate that Pachycara thermophilum (Geistdoerfer, 1994) and P. saldanhai (Biscoito and Almeida, 2004) (Perciformes: Zoarcidae) from the Mid-Atlantic Ridge are synonyms speciesPublication . Stefanni, S.; Porteiro, F. M.; Bettencourt, R.; Gavaia, Paulo J.; Santos, Ricardo SerrãoThe genus Pachycara comprises of 20 species distributed across the globe. Due to difficulties in collecting these fish, most of the species were described from single or few individuals. Until now, the systematics for these species has been based on traditional taxonomy and the only studies with molecular interest were performed on the Circum Antarctic Pachycara brachycephalum.
- Functional analysis of bone related Gla proteins from bony fish during skeletal developmentPublication . Gavaia, Paulo J.; Cancela, LeonorAs proteinas dependentes da vitamina K, proteína Gla do osso (BGP ou osteocalcina) e proteína Gla da matriz (MGP) são pequenas proteinas que ligam o cálcio, tendo sido recentemente descobertas em peixe.
- Nutrition, quality and performance in marine fish larvaePublication . Conceição, L. E. C.; Alves-Martins, D.; Engrola, S.; Gavaia, Paulo J.; Richard, Nadège; Aragão, C.O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de qualidade, nomeadamente malformações esqueléticas. A solução de parte destes problemas passa por uma melhor compreensão dos requisitos nutricionais. Este trabalho pretende fazer uma revisão de trabalhos recentes que demonstram como os aminoácidos, os ácidos gordos e a vitamina K, mas também o regime alimentar, podem influenciar a qualidade e a performance das larvas de peixes marinhos.
- Tolerance of zebrafish embryos to supra-physiologic yolk levels of glucosePublication . Rocha, F.; Dias, J.; Engrola, S.; Gavaia, Paulo J.; Dinis, Maria Teresa; Panserat, S.Once spawned and fertilized the oviparous fish eggs operate as closed systems; only respiratory gases, heat and negligible amounts of solutes and water are exchanged freely, as a result of an extremely low permeability of the egg surface membranes. Currently, the opportunities to exert a nutritional stimulus during a stage of high metabolic plasticity, such as fish embryogenesis, are restricted to maternal transfer and the onset of exogenous feeding.
- 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.
- Osteological development and abnormalities of the vertebral column and caudal skeleton in larval and juvenile stages of hatchery reared solea senegalensis (kaup)Publication . Gavaia, Paulo J.; Dinis, Maria Teresa; Cancela, LeonorThe Senegal sole is a species recently adapted to aquaculture for which little information on larval development is available. This study was designed to describe normal skeletal development and the occurrence of skeletal malformations in Senegal sole reared in captivity. Eggs were collected from natural spawning, incubated until hatching and larvae reared to the juvenile stage in a closed recirculating system. Samples were collected throughout development at regular intervals from hatching to fully formed juveniles. Specimens were stained with alcian blue and alizarin red and observed for skeletal development and detection of anomalies. A high number of malformations were detected, both in the caudal complex and the vertebral column. About 44% of the individuals observed showed at least one malformation and the highest occurrence of deformities was observed in the caudal region and in the vertebral column. Accordingly, 28% of the total deformities identified in this study were detected at those sites and in adjacent arches and spines. The causes were not identified in this study, but the high incidence of malformations may reflect culture problems due to rearing and/or feeding conditions that affect skeletal development.
- 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.
- Novel methodologies in marine fish larval nutritionPublication . Conceição, L. E. C.; Aragão, C.; Richard, Nadège; Engrola, S.; Gavaia, Paulo J.; Mira, Sara; Dias, J.Major gaps in knowledge on fish larval nutritional requirements still remain. Small larval size, and difficulties in acceptance of inert microdiets, makes progress slow and cumbersome. This lack of knowledge in fish larval nutritional requirements is one of the causes of high mortalities and quality problems commonly observed in marine larviculture. In recent years, several novel methodologies have contributed to significant progress in fish larval nutrition. Others are emerging and are likely to bring further insight into larval nutritional physiology and requirements. This paper reviews a range of new tools and some examples of their present use, as well as potential future applications in the study of fish larvae nutrition. Tube-feeding and incorporation into Artemia of 14C-amino acids and lipids allowed studying Artemia intake, digestion and absorption and utilisation of these nutrients. Diet selection by fish larvae has been studied with diets containing different natural stable isotope signatures or diets where different rare metal oxides were added. Mechanistic modelling has been used as a tool to integrate existing knowledge and reveal gaps, and also to better understand results obtained in tracer studies. Population genomics may assist in assessing genotype effects on nutritional requirements, by using progeny testing in fish reared in the same tanks, and also in identifying QTLs for larval stages. Functional genomics and proteomics enable the study of gene and protein expression under various dietary conditions, and thereby identify the metabolic pathways which are affected by a given nutrient. Promising results were obtained using the metabolic programming concept in early life to facilitate utilisation of certain nutrients at later stages. All together, these methodologies have made decisive contributions, and are expected to do even more in the near future, to build a knowledge basis for development of optimised diets and feeding regimes for different species of larval fish.