Nutrition and farming practices as modulators of quality in gilthead seabream (Sparus aurata)

Gilthead seabream is the most important farmed species in the Mediterranean, and knowledge on how common farming practices impact its quality is limited. As such, this Thesis aimed to evaluate how gilthead seabream flesh quality is affected by some of these practices. In Chapter 2, the influence of nutritional factors was evaluated, specifically the high replacement of traditional marine-derived ingredients, both fishmeal and fish oil, with vegetable sources. We have seen that the vegetable-based diets tested did not greatly impact seabream flesh quality, although some alterations were seen in the fatty acid profile of the muscle. However, and despite having caused no alterations in flesh texture, vegetable ingredients reduced the amount of sulphated glycosaminoglycans in the extracellular matrix, affected muscle pH and reduced the activity of proteolytic enzymes. Throughout this Thesis, we measured for the first time the activity of proteolytic enzymes in seabream muscle, and cathepsin B was found to play a pivotal role in post-mortem muscle degradation. In Chapter 3, we evaluated the effect of harvesting and slaughter stress on seabream quality, and contrary to what is seen in most farmed species, our results show that gilthead seabream muscle structure is highly resistant to changes caused by stressful events. Nonetheless, considering that welfare is an increasingly important quality criterion, the use of a zero-withdrawal anaesthetic as a rested harvest technique or even slaughter method could prove valuable to the industry. In Chapter 4, we used maslinic acid as a dietary supplement, to modulate the muscle’s energetic status pre-mortem. As a finishing strategy, maslinic acid failed to increase levels of glycogen and ATP in the muscle. However, supplementation resulted in higher muscle fibre diameter and lower cathepsin B activity, and maslinic acid is likely to be useful to promote growth in this species. In general our Thesis has generated new knowledge to a major challenge facing the aquaculture industry, which is to find a compromise between the trends towards intensive rearing and consumer demand for healthy, high quality seafood being ethically acceptable and having a low impact on the environment.

Development of chitosan packaging films with carvacrol and grape seed extract as antimicrobial and antioxidant agents

In order to produce packaging films with a broad spectrum of action on microorganisms, the effect of two antimicrobial (AM) to be included in the films, carvacrol and GSE were studied separately on different microorganisms. Carvacrol was more effective against the grampositive bacteria than against the gram-negative bacterium. GSE was not effective against yeast. Subsequently, a search for optimal combinations of carvacrol, GSE and the addition of chitosan (as a third component with film forming properties) was carried out. Response surface analysis showed several synergetic effects and three optimal AM combinations (OAMC) were obtained for each microorganism. The experimental validation confirmed that the optimal solutions found can successfully predict the response for each microorganism. The optimization of mixtures of the three components, but this time, using the same concentration for all microorganisms, was also studied to obtain an OAMC with wide spectrum of activity. The results of the response surface analysis showed several synergistic effects for all microorganisms. Three OAMC, OAMC-1, OAMC-2, OAMC-3, were found to be the optimal mixtures for all microorganisms. The radical scavenging activity (RSA) of the different agents was then compared with a standard antioxidant (AOX) BHT, at different concentrations; as also at the OAMC. The RSA increased in the following order: chitosan-2-1-3. The best AOX solution, OAMC-3 was applied as a coating in food. P. aeruginosa was the more sensitive and S. aureus was the most resistant to the action of OAMC-3. The physico-mechanical properties of 3 films, film-1 with OAMC-1, film-2 with OAMC-2 and film-3 with OAMC-3 were studied. Film-3 presented the lowest WVP, CO2P and TS values and the highest O2P whereas film-1 presented the highest WVP and the lowest crystallinity, CO2P, TS and luminosity. Being one of the components of GSE, gallic acid (GA) release in water from film-1, film-2 and film-3 was next studied over a 30 day period. The mathematical model for the release of GA based on Fick’s law successfully fitted the experimental data and GA diffusion coefficients, assumed to be Arrhenius temperature dependent were obtained for each film. This work will contribute to the development of environmentally friendly packaging films, resulting in improved food preservation and shelf-life extension.

Estudo ambiental da nova ligação ferroviária de alta velocidade Faro - Huelva

Com a publicação do Decreto-Lei n.º 232/2007, de 15 de Junho, a Avaliação Ambiental Estratégica (AAE) tornou-se um procedimento técnico de carácter obrigatório em Portugal. Pretende-se com este trabalho abordar esta temática com o objectivo de verificar a melhor hipótese de traçado para a ligação ferroviária de alta velocidade Faro-Huelva, através da comparação de dois métodos de avaliação. A área em estudo pertence Sotavento Algarvio, abrangendo os concelhos de Faro, Olhão, S. B. de Alportel, Tavira, Alcoutim, Castro Marim e Vila Real de Santo António. A metodologia utilizada será a sobreposição de mapas (com recurso a Sistemas de Informação Geográfica) e as matrizes de Leoplod, metodologias mais aplicadas a estudos de Avaliação Ambiental para o sector dos Transportes. A utilização destas metodologias permitirá averiguar qual a mais consistente para estes estudos de caso, facultando a informação de maior relevo aos decisores e às entidades. Verificou-se que a criação de uma linha ferroviária de Alta Velocidade no Algarve é possível, tendo em atenção os factores ambientais, de forma a minimizar o seu impacte. Pela análise matricial, os principais impactes negativos derivados deste projecto são maioritariamente decorrentes da fase de construção, e associam-se à ocupação e compactação dos solos de forma irrevogável, afectando zonas edificadas e zonas agrícolas e florestais, ocupação de solos REN e RAN, Zonas de Especial Conservação. Os positivos decorrem essencialmente da fase de exploração, associados às vantagens da utilização deste meio de transporte, como é o caso do desenvolvimento económico da região e do país, encurtando a distância e o tempo entre a Algarve e Espanha, com ligação a toda a Europa.

Relatório de atividade profissional: desenvolvimento de novos produtos em áreas de destino - o caso do birdwatching no Algarve

O desenvolvimento de novos produtos tem sido apontado como sendo, mais do que um caminho, a forma dos destinos turísticos se rejuvenescerem e fazerem face à crescente competitividade que parece, cada vez mais, caracterizar esta atividade. A região algarvia, com alto grau de especialização no turismo, parece não querer alhear-se desta realidade e tem vindo, paulatinamente, a desenvolver um novo olhar sobre o seu território, os seus recursos, bem como sobre a procura turística (atual e potencial). Sendo tradicionalmente identificado e conotado com o produto sol e mar, o Algarve tem tentado, ao longo dos anos, alargar a base da sua oferta, numa tentativa de atenuar os efeitos da elevada sazonalidade que afeta a região, bem como para serem criadas complementaridades com a oferta principal, valorizando-a. Nesse contexto se justificam as apostas nos restantes produtos consignados como estratégicos para a região no Plano Estratégico Nacional de Turismo (PENT): golfe, meeting industry (congressos e incentivos), turismo náutico, saúde e bem-estar, turismo residencial. Não obstante este esforço, parece ser consensual entre os diversos intervenientes do setor que há ainda trabalho a desenvolver neste campo. De facto a região continua a estar sujeita a uma procura concentrada sobretudo no período de verão, algo facilmente confirmado pela análise dos principais indicadores da atividade turística. Tal parece indiciar uma necessidade de se reforçar a aposta em produtos que contribuam para a diversificação da oferta, sobretudo nos que permitam captar fluxos no período compreendido entre outubro e abril. Atenta a esta necessidade, a Entidade Regional de Turismo do Algarve (ERTA), organismo que chama a si a responsabilidade da gestão do marketing do destino, fez uma aposta fundamentada no desenvolvimento do produto birdwatching na região, processo aqui relatado. Apoiada numa parceria com a associação ambientalista algarvia Almargem, e com a Sociedade Portuguesa para o Estudo das Aves (SPEA), a ERTA começou por identificar as áreas geográficas do Algarve com maior potencialidade para esta prática (hotspots), fazendo um levantamento das necessidades de intervenção para a valorização dos espaços e apontando caminhos para promoção do produto. Os resultados foram refletidos num relatório denominado “Birdwatching no Algarve – propostas de estruturação e organização” (ERTA, 2009b). Ainda no âmbito do desenvolvimento do produto e conscientes da necessidade de recolher alguma informação sobre o birdwatching no Algarve, situação que foi identificada como sendo deficitária, foi ainda apoiado o desenvolvimento de uma dissertação de mestrado (Machado, 2011). Tal veio a possibilitar suprir esta lacuna, bem como ajudar na orientação de algumas das ações a desenvolver, em função dos perfis traçados. Toda a informação apurada, coligida e transposta quer no relatório “Birdwatching no Algarve – propostas de estruturação e organização” (ERTA, 2009b), quer na dissertação desenvolvida pela mestranda veio a demonstrar-se ser extremamente valiosa na fundamentação das opções tomadas, bem como na abordagem a outros parceiros, nomeadamente as câmaras municipais e Instituto de Conservação da Natureza e da Floresta (ICNF), ambos com capacidade de intervenção ao nível da gestão territorial. Conscientes de que o papel da ERTA neste processo deveria ser de dinamizador e de coordenador do processo (até por força da sua definição de competências), tentando que haja coerência e consistência regional, levou a que esta entidade desenvolvesse ainda um conjunto de ações de suporte à boa implementação do projeto por parte dos parceiros, nomeadamente: Identidade visual do subproduto birdwatching – contemplando não só o logótipo criado para o efeito, como o respetivo manual de normas de aplicação do mesmo; Projeto de estruturas-tipo para observação de aves – de forma a tentar evitar que o conjunto de infraestruturas de suporte a esta atividade, aquando do seu desenvolvimento pelas câmaras municipais e ICNF, fossem muito heterogéneos ao longo do território, foi facultado aos parceiros um conjunto de projetos de arquitetura para as estruturas tipo que haviam já sido identificadas no relatório “Birdwatching no Algarve – propostas de estruturação e organização” (ERTA, 2009b): plataformas de observação; observatórios; abrigos; painéis informativos; passadiços; bancos; caixotes de lixo; outros. Não obstante a materialização do projeto em si ter caído num certo impasse, fruto da conjuntura atual, que tem condicionado a possibilidade dos municípios e ICNF intervirem nos seus territórios, edificando infraestruturas, ou fazendo arranjos nas zonas identificadas como prioritárias, várias outras ações têm sido concretizadas: Criação de desdobrável informativo/promocional com a principal informação sobre birdwatching na região; Participação em diversos certames internacionais alusivos a esta prática, promovendo desta forma a região; Criação de guia de birdwatching no Algarve; Organização de diversas fam trips e press trips internacionais, para mostrar o trabalho que tem vindo a ser desenvolvido, bem como as potencialidades da região. Ainda que o projeto de desenvolvimento do birdwatching no Algarve esteja longe da sua conclusão, estamos em crer tratar-se de uma boa aposta na tentativa de alargar a base de produtos turísticos disponíveis na região. De facto, a recetividade evidenciada por todos os intervenientes do setor tem vindo a demonstrar a pertinência da aposta, bem como do acerto na atuação da ERTA no seu papel de gestora do marketing do destino, nomeadamente na vertente de desenvolvimento de novos produtos.

Crescimento e condição nutricional de larvas de sardinha em condições controladas

Com o objectivo de determinar o crescimento de larvas de sardinha foram realizadas experiências em condições controladas. Um cardume de sardinhas adultas foi mantido em cativeiro e a desova induzida por meios naturais (aumento da disponibilidade alimentar, regulação da temperatura para cerca de 15º C e salinidade para ~35‰). Quando ocorreram desovas com mais do que 500 ovos num determinado dia, estes foram colocados a eclodir em condições controladas. As larvas de sardinha apresentaram um desenvolvimento morfológico normal (p.e. pigmentação dos olhos e desenvolvimento da boca entre o 3º e 4º dia). Diferentes tipos e combinações de alimentos foram experimentados (nauplios de Acartia grani, rotíferos e Gymnodinium sp.) e analisou-se a condição nutricional das larvas amostradas. Foram efectuadas experiências de inanição para se poder calibrar os resultados obtidos. As taxas de crescimento variaram entre 0.12 e 0.36 mm.dia-1, sendo a mais elevada correspondente a uma experiência de inanição. Observou-se, através da histologia, que dietas ricas em Acartia grani são mais favoráveis para um melhor desenvolvimento larvar. As análises da razão RNA/DNA sugerem que há uma forte possibilidade de os efeitos parentais terem bastante influência no desenvolvimento e crescimento das larvas de sardinha nas duas primeiras semanas de vida, mas não na sua sobrevivência, que dependeu da quantidade e qualidade de alimento fornecida.

Cartografia da densidade bentónica do Algarve central e previsões de cenários

Os fundos marinhos do Algarve central são cada vez mais sujeitos a pressões antropológicas. A pesca, a extração de inertes para reabastecimento de praias, os recifes artificais e aquacultura costeiras são exemplos de actividades que se desenvolvem nesse espaço. O conhecimento da variação espacial da densidade bentónica é um desafio que se coloca cada vez mais à comunidade científica. Para além do interesse para o conhecimento científico é também valioso intrumento de gestão ambiental. Numa altura em que existe cada vez pressão sobre o ambiente marinho, a gestão sustentada dos espaços, compatibilizando a conservação e as actividades, assente num conhecimento científico, é cada vez mais necessária. Este estudo, teve como objectivo, a criação de modelos que descrevam espacialmente as densidades de peixes (bentónicos e demersais) e de macroinvertebrados obtidas na área de estudo, os substratos móveis até aos 30 m de profundidade no Algarve Central. E ainda, a elaboração de cenários, nomeadamente na identificação de zonas com densidades mais elevadas, impacte de dragagens e um aumento da temperatura superficial do mar. Os modelos obtidos são representativos das realidades amostradas. Os resultados indicam a existência de variação sazonal nos locais de amostragem com as maiores densidades a ocorrerem na zona central da área de estudo e também em maiores profundidades. A simulação de uma área de dragagem indica, após o período de impacto inicial que não foi contabilizado, um provável aumento de densidade como consequência do aumento de profundidade na área impactada. A simulação do aumento da temperatura superficial do mar, indica a existência de uma diminuição das densidades bentónicas.

A value chain analysis of tuna industry in Ghana

Every can of tuna purchased by the consumer has taken a long journey before reaching the supermarket shelves. For each can bought there is a lengthy process from sea to shelf. A large proportion of the tuna cans purchased in the European Union come all the way from West Africa; a developing region with a high dependency on fisheries. Amidst an ever-increasing demand for tuna products the global tuna fisheries are set to continue expanding, apparently one of the last natural resource based industries fit to do so in West Africa. Tuna is the biggest fisheries export and dominates the fisheries sector in Ghana, a country situated in West Africa. This thesis aims to understand how this globally important industrial fisheries functions in terms of procedures, practices, Governance and finance. Socioeconomic influences, in the setting of a developing country, were also examined. For these purposes a Value Chain Analysis was employed. A Value Chain Analysis is a tool commonly used to understand how different companies and organizations participate in a domestic policy environment, which directs conclusion in the global economy. This analysis has the potential to allow researchers to fully understand a commodity chain and hence identify realistic opportunities for consequential improvements. Interviews and questionnaires were employed in-field Ghana along with secondary data collection techniques. It was found that the fisheries functions at the production level under influences from large multinational companies and tends to operate with a certain degree of lawlessness. Governance over the value chain is well defined, however implementation is poor or non-existent. The processors, whom are also dominated by multinationals, exert some control over the producers and their sales, however the high value links which are highlighted occur at the retail stage. Socioeconomic dynamics acting in the chain included the lack of communication between the public and private sector, power imbalances amongst players at production, the role of local businesswomen as actors in the chain and the general characteristics of the workers in the industry. Value addition and upgrading are needed the most in Governance over the chain, especially within Monitoring, Control and Surveillance. The results of the study provide a wealth of material about the components of a cost-heavy fishing industry in a developing country; an industry on which many eyes have recently turned due to illegal fishing activities. It highlights clearly where funding and future focus are needed. This value chain can be used as a guide for those that need to comprehend the financial complexities and real life dynamics of the Ghanaian tuna fishing industry today.

O Arquivo Histórico Municipal de Vila Real de Santo António na base da aquisição de conhecimentos e experiência profissional na área de arquivo

Neste relatório descreve-se a atividade profissional de um Assistente Técnico de Arquivo desenvolvida ao longo de seis anos no Arquivo Histórico Municipal de Vila Real de Santo António, no âmbito do plano curricular do Mestrado em Ciências Documentais - Área Arquivo, ministrado pela Faculdade de Ciências Humanas e Sociais da Universidade do Algarve. Tentarei trazer à memória de todos quantos lerem este relatório o enquadramento histórico e a evolução administrativa local da Câmara Municipal de Vila Real de Santo António que tutela o Arquivo Histórico Municipal. Darei a conhecer o surgimento e a razão de ser do Arquivo Histórico Municipal, assim como, as suas funções e atribuições. Caracterizarei o arquivo corrente, intermédio e histórico existente na Câmara Municipal de Vila Real de Santo António. Exemplificarei como são integrados os documentos neste Arquivo, qual o procedimento quando um documento é requisitado à instituição, e qual a sua tramitação até a documentação ser encaminhada para a eliminação ou para a conservação definitiva, fazendo uma reflexão crítica de alguns dos procedimentos adotados e tendo em conta os princípios arquivísticos aceites universalmente. Salientarei qual, o impacto dos agentes biológicos na conservação de um acervo documental, e a importância de manter periodicamente um controle e monitorização de pragas. Destacarei, finalmente, a importância da preservação digital na instituição arquivística e da relevância da função cultural de um arquivo municipal.

The effect of conservation measures on the spatial and temporal variation of rocky fish assemblages in the Arrábida Marine Park

Marine protected areas (MPAs) have been widely proposed for conservation purposes and as a tool for fisheries management. The Arrábida Marine Park is the first MPA in continental Portugal having a management plan, fully implemented since 2009. The main objective of this study was to evaluate the effect of protection measures on rocky reef fish assemblages and target invertebrates through before-after and control-effect (no-take vs. fished areas) underwater visual surveys and analysis of landings trends. Second, we used surveys before, during and after implementation of the management plan to understand fishers‟ preferences for fishing grounds and adaptation to the new rules, and evaluated the reserve effect through analysis of both ecological responses and fishing effort density. Third, we identified the main oceanographic drivers influencing the structure of reef fish assemblages and predicted the community structure for the last 50 years, in light of climatic change. Overall results suggest positive responses in biomass but not yet in numbers of some commercial species, with no effects on non-target species. The reserve effect is reinforced by the increase in landings of commercial species, despite increased fishing effort density in some areas, especially with octopus traps. Fishing grounds are mainly chosen based on the distribution of target species and associated habitats, but distance to port, weather conditions and safety also influence fishers‟ choices. Moreover, different fisheries respond differently to the protection measures, and within each fishery, individual fishers show distinct strategies, with some operating in a broader area whereas others keep preferred territories. Our results also show that wind stress and temperature are the main oceanographic drivers for rocky reef fish assemblages, with tropicalization of assemblages and polewards movements of species over the last 50 years consistent with temperature trends. We believe this study provides significant lessons for marine conservation and management of coastal systems.

Evolution, gene regulation and functional analysis of BMP2 in fish

Bone morphogenetic proteins (BMPs) are multifunctional growth factors belonging to the transforming growth factor β (TGFβ) superfamily with a central role in bone formation and mineralization. BMP2, a founding member of this family, has demonstrated remarkable osteogenic properties and is clinically used to promote bone repair and fracture healing. Lack of basic data on factors regulating BMP2 expression and activity have hampered a better understanding of its role in bone formation and bone-related diseases. The objective of this work was to collect new functional data and determine spatiotemporal expression patterns in a fish system aiming towards a better understanding of BMP2 function and regulation. Transcriptional and post-transcriptional regulation of gilthead seabream BMP2 gene was inferred from luciferase reporter systems. Several bone- and cartilage-related transcription factors (e.g. RUNX3, MEF2c, SOX9 and ETS1) were found to regulate BMP2 transcription, while microRNA 20a was shown to affect stability of the BMP2 transcript and thus the mineralogenic capacity of fish bone-derived host cells. The regulation of BMP2 activity through an interaction with the matrix Gla protein (MGP) was investigated in vitro using BMP responsive elements (BRE) coupled to luciferase reporter gene. Although we demonstrated the functionality of the experimental system in a fish cell line and the activation of BMP signaling pathway by seabream BMP2, no conclusive evidence could be collected on a possible interaction beween MGP and BMP2. The evolutionary relationship among the members of BMP2/4/16 subfamily was inferred from taxonomic and phylogenetic analyses. BMP16 diverged prior to BMP2 and BMP4 and should be the result of an ancient genome duplication that occurred early in vertebrate evolution. Structural and functional data suggested that all three proteins are effectors of the BMP signaling pathway, but expression data revealed different spatiotemporal patterns in teleost fish suggesting distinct mechanisms of regulation. In this work, through the collection of novel data, we provide additional insight into the regulation, the structure and the phylogenetic relationship of BMP2 and its closely related family members.

Recreational shore fishing in southern Portugal: biological and socio-economic aspects and perspectives for management

Although overfishing is a concern for many fish stocks, it was for a long time only associated with commercial fishing exploitation, with less or no attention being given to the recreational fisheries. Recent research has shown however that the impact of recreational fishing on particular species can be considerable, and that the recreational harvest needs to be taken into account if fisheries are to be accurately assessed and effectively managed. In Portugal, the first recreational fishing regulations were only recently implemented. However, mirroring other European countries, regulations lacked scientific support, and specific knowledge of the activity was limited to a few studies with limited coverage. This thesis aimed to characterize the biological and socioeconomic aspects of the recreational shore angling activity in southern Portugal, to investigate whether the regulations in place were adequate and effective, and to provide recommendations for improved management and conservation of the inshore fisheries resources. A combined aerial-roving survey was conducted to gather data on fishing effort, catch, fishing trips and socioeconomic aspects (including anglers’ perceptions of regulations) of the recreational angling activity. The analysis of anglers’ catches suggested that compliance with daily bag limits was high, with less than 0.5% of creels exceeding the 10 kg angler-1 day-1 bag limit. Overall, 11.5% of the retained fishes were undersized, but non-compliance with minimum size limits was found to be high for some species (e.g. seabass, 73% undersized). In terms of the impact of recreational shore angling, the total estimated catches corresponded to less than 1% of the commercial landings for the same period (shared species). However, shore angling catches for white sea bream (Diplodus sargus) were found to be considerable, corresponding to 65% of the commercial landings (39.4% of total catch). In terms of anglers’ perceptions about the recreational fishing regulations in Portugal, the present study has shown that the majority of anglers accepted the existence of some kind of SRF regulations, but in general there was a partial or total disagreement with the recreational fishing restrictions recently put in place. Most anglers perceived themselves as not being involved in the decision-making process and claimed that some restrictions lacked a meaningful rationale (e.g. prohibition of fishing from piers/jetties). Fishers’ awareness with regard to specific aspects of the restrictions (such as the rationale for minimum size limits) was found to be very limited. During the same period, catches from sport fishing competitions were examined to test for differences with the recreational activity in terms of catches, and evaluate long term trends in catch and mean size of fish. Catches of the sport fishing competitions were found to be different from those observed for recreational fishing, being dominated by different species (e.g. garfish, mullets), and suggesting different fishing strategies of the the two types of anglers. High percentages of undersized fish were observed to be captured (and retained) during the competitions (in particular seabass, with 100% undersized), probably as a result of a single allowable minimum size (AMS) of 15 cm for all species in use in competitions. Lastly, catch and release fishing experiments were carried out to assess post-release mortality of three recreationally important species: two banded sea bream Diplodus vulgaris; black sea bream Spondyliosoma cantharus; and gilthead sea bream Sparus aurata. Post-release mortalities were found to be low (0-12%). The main predictor of mortality for Sparus aurata was anatomical hooking location, with 63% of the fishes that died being deeply hooked. The results support the release of fish, either from mandatory (e.g. minimum landing sizes) or voluntary practices. In summary, this thesis has demonstrated that the impact of recreational fishing for particular species is significant and needs to be taken into account for more effective management and stock assessment purposes. It has also highlighted several management issues that should be addressed in order to promote more adequate regulations in the future and prevent noncompliance issues. A periodic monitoring of the recreational fishing activity including all fishing modes (i.e. spear fishing, boat, and shore angling) would also be beneficial to ensure a timely knowledge on the global recreational fishing activity and support future management actions.

Gestão do percebe (Pollicipes pollicipes (Gmelin, 1790)) no Parque Natural do Sudoeste Alentejano e Costa Vicentina

Dissertação de mestrado, Gestão e Conservação da Natureza, Faculdade de Ciências do Mar e Ambiente, Universidade do Algarve, 2004

Molecular characterization of Gla-rich protein (GRP) gene expression and function

Gla-rich protein (GRP) is a vitamin K-dependent protein related to bone and cartilage recently described. This protein is characterized by a large number of Gla (γ-carboxyglutamic acid) residues being the protein with the highest Gla content of any known protein. It was found in a widely variety of tissues but highest levels was found in skeletal and cartilaginous tissues. This small secreted protein was also expressed and accumulated in soft tissues and it was clearly associated with calcification pathologies in the same tissues. Although the biological importance of GRP remains to be elucidated, it was suggested a physiological role in cartilage development and calcification process during vertebrate skeleton formation. Using zebrafish, an accepted model to study skeletal development, we have described two grp paralog genes, grp1 and grp2, which exhibited distinct patterns of expression, suggesting different regulatory pathways for each gene. Gene synteny analysis showed that grp2 gene is more closely related to tetrapod grp, although grp1 gene was proposed to be the vertebrate ortholog by sequence comparison. In addition, we identified a functional promoter of grp2 gene and using a functional approach we confirmed the involvement of transcription factors from Sox family (Sox9b and Sox10) in the regulation of grp2 expression. In an effort to provide more information about the function of grp isoforms, we generated two zebrafish transgenic lines capable to overexpress conditionally grp genes and possible roles in the skeleton development were studied. To better understand GRP function a mammalian system was used and the analysis of knockout mice showed that GRP is involved in chondrocyte maturation and the absence of GRP is associated to proteoglycans loss in calcified articular cartilage. In addition, we detected differences in chondrogenesis markers in articular chondrocyte primary culture. Overall, our data suggest a main role for GRP on chondrocyte differentiation.

Molecular structure and functional analysis of runx3 in zebrafish

Tese de doutoramento, Ciências Biomédicas, Universidade do Algarve, Departamento de Ciências Biomédicas e Medicina, 2014

Técnicas de valorização contingencial aplicadas ao ambiente : estudo de cenários para a Ilha da Culatra

Doutoramento em Economia, Faculdade de Economia, Universidade do Algarve, 2001