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Publications

Mgp expression and accumulation in heart and kidney of turbot (Scophthalmus maximus)

Publication . Roberto, Vania Palma; Cavaco, S.; Simes, D; Gavaia, Paulo J.; Cancela, Leonor

Matrix γ-carboxyglutamic acid (Gla) protein (Mgp) is a vitamin K-dependent protein normally found associated with the organic matrix of cartilage and bone in vivo. After the discovery of Mgp in various soft tissues, this protein was proposed to act as a local inhibitor of mineralization although its molecular mechanisms of action remain incompletely understood.

2009Conference object

Open access

Skeletal evaluation and technical improvements to decrease the incidence of skeletal deformities in Solea senegalensis, Kaup

Publication . Gavaia, Paulo J.; Richard, Nadège; Dâmaso, L.; Dinis, Maria Teresa; Pousão-Ferreira, P.; Engrola, S.; Conceição, L. E. C.; Cancela, Leonor

The appearance of skeletal deformities is a major problem associated to intensive, large-scale culture of fish species, affecting growth, development and ultimately, survival of produced fish. Although the mechanisms working behind it are still unclear, it is known that environmental, genetic and nutritional factors play fundamental roles. Given its importance as a vertebrate model to study skeleton-related diseases, the selection of an appropriate dietary protocol is a critical step in order to diminish the nutritional effect on bone and cartilage development. To better understand the effect of diet on skeletal development and deformities, as well as on larvae and juvenile global performance, we have tested four distinct dietary regimes, composed of rotifers Brachionus sp., Artemia nauplii and dry, formulated food.

2009Conference object

Open access

Matrix Gla protein expression: a complex process involving the use of alternative promoters, multiple splicing events and microRNAs

Publication . Cancela, Leonor; Laizé, Vincent; Conceição, N.; Tiago, Daniel; Maia, Ana-Teresa; Bensimon-Brito, A.; Gavaia, Paulo J.

Matrix Gla protein (MGP) is a secreted vitamin K-dependent protein (VKD) located in the extracellular matrix and capable of binding calcium through its -carboxyglutamate residues. Although identified in 1983, transcriptional and post-transcriptional mechanisms regulating its expression remain unclear.

2012Conference object

Open access

O efeito da dieta na sobrevivência e no desenvolvimento esquelético e digestivo de larvas e juvenis de peixe-zebra Danio rerio (Hamilton, 1822)

Publication . Silva, João Pedro Gonçalves Cardeira da; Cancela, Leonor; Gavaia, Paulo J.

Zebrafish is a freshwater teleost which, due to several biological and genetic characters, has been widely used as a vertebrate model in a variety of research fields, with great potential in molecular biology. As a consequence of the increasing interest in zebrafish, the optimization of its rearing conditions becomes essential, such as the determination of a standardized feeding regime appropriate to this species’. Four different dietary regimes, composed of rotifers Brachionus sp., Artemia nauplii and inert food (Cyclop-eezeTM e BeneluxNV), were carried out. The effect of diet in zebrafish larvae and juvenile fish was evaluated by the determination of the survival and growth parameters as well as by the analysis of the development at the tissue, cellular and molecular levels in three distinct developmental stages. For that, histological, gene expression and immunohistochemical tools applied to molecular markers of the skeletal development (matrix Gla protein – mgp – and osteocalcin – oc) and digestive tract development (amylase and trypsin) were used. The assessment of bone remodeling regions and a histological analysis of the digestive system were also carried out. The obtained data suggest that rotifers are not appropriate for the larval requirements of this species, presenting the lowest survival and growth values. These data were also supported at the molecular level. Artemia nauplii and a weaning to inert food at 15 days post fertilization does not seem to be, also, an appropriate feeding regime. Comparatively, a diet composed exclusively by Artemia nauplii presented higher development-related parameters. These data suggest that this is a suitable food regime, as it has been argued by several authors. A daily mixture of foods also seems to be suitable to zebrafish healthy development. This work showed that, in zebrafish early development Artemia nauplii should used as food and could be, possibly, supplemented with other foods to obtain better results.

2009Master thesis

Open access