Involvement of Gla proteins MGP and Osteocalcin in the processes of mineralization occurring in marine versus fresh water teleosts.

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Publications

Characterization of osteocalcin (BGP) and matrix gla protein (MGP) fish specific antibodies: validation for immunodetection studies in lower vertebrates

Publication . Simes, D; Williamson, M. K.; Schaff, Brian J.; Gavaia, Paulo J.; Ingleton, P. M.; Price, P. A.; Cancela, Leonor

In 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.

2004Journal article

Unknown

Osteocalcin and Matrix Gla Protein in zebrafish (Danio rerio) and Senegal sole (Solea senegalensis): comparative gene and protein expression during larval development through adulthood

Publication . Gavaia, Paulo J.; Simes, D; Ortiz-Delgado, J. B.; S B Viegas, Carla; Pinto, Jorge; Kelsh, R. N.; Sarasquete, C.; Cancela, Leonor

Bone Gla protein (Bgp or osteocalcin) and matrix Gla protein (Mgp) are important in calcium metabolism and skeletal development, but their precise roles at the molecular level remain poorly understood. Here, we compare the tissue distribution and accumulation of Bgp and Mgp during larval development and in adult tissues of zebrafish (Danio rerio) and throughout metamorphosis in Senegal sole (Solea senegalensis), two fish species with contrasting environmental calcium levels and degrees of skeletal reorganization at metamorphosis. Mineral deposition was investigated in parallel using a modified Alizarin red/Alcian blue protocol allowing sensitive simultaneous detection of bone and cartilage. In zebrafish, bgp and mgp mRNAs were localized in all mineralized tissues during and after calcification including bone and calcified cartilage of branchial arches. Through immunohistochemistry we demonstrated that these proteins accumulate mainly in the matrix of skeletal structures already calcified or under calcification, confirming in situ hybridization results. Interestingly, some accumulation of Bgp was also observed in kidney, possibly due to the presence of a related protein, nephrocalcin. Chromosomal localization of bgp and mgp using a zebrafish radiation hybrid panel indicated that both genes are located on the same chromosome, in contrast to mammals where they map to different chromosomes, albeit in regions showing synteny with the zebrafish location. Results in Senegal sole further indicate that, during metamorphosis, there is an increase in expression of both bgp and mgp, paralleling calcification of axial skeleton structures. In contrast with results obtained for previously studied marine fishes, in zebrafish and Senegal sole Mgp accumulates in both calcified tissues and non-mineralized vessel walls of the vascular system. These results suggest different patterns of Mgp accumulation between fish and mammals.

2006Journal article

Unknown

Regeneration in Zebrafish (Danio rerio) fins: pattern of expression of mineralization–related Gla proteins

Publication . Brito, A. B.; Gavaia, Paulo J.; Cancela, Leonor

Teleost fishes have the exceptional ability to largely regenerate severed appendages comprising several different tissues. Fin regeneration starts through the formation of heterogeneous mesenchyma-like cells, named blastema, and 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. Matrix Gla Protein (Mgp) and Bone Gla Protein (Bgp, osteocalcin) are small extracellular matrix Gla proteins, members of the vitamin K-dependent (VKD) family.

2006Conference 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

Molecular insights indicate that Pachycara thermophilum (Geistdoerfer, 1994) and P. saldanhai (Biscoito and Almeida, 2004) (Perciformes: Zoarcidae) from the Mid-Atlantic Ridge are synonyms species

Publication . Stefanni, S.; Porteiro, F. M.; Bettencourt, R.; Gavaia, Paulo J.; Santos, Ricardo Serrão

The 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.

2007Journal article

Unknown