Evolução da produção de leite em pequenos ruminantes: polimorfismos do gene da hormona de crescimento

Os efetivos autóctones de pequenos ruminantes têm vindo a diminuir,em parte devido ao seu baixo potencial produtivo. A necessidade de encontrar formas mais expeditas de aumentar o potencial produtivo das nossas raças, e assim promover a sua manutenção bem como a sustentabilidade dos sistemas extensivos onde são explorados, levou à procura de marcadores moleculares, nomeadamente no gene da hormona de crescimento (GH), associados com a produção e qualidade do leite em pequenos ruminantes. Nas raças ovinas Churra da Terra Quente, Merino da Beira Baixa, Saloia e Serra da Estrela e caprinas Algarvia e Serrana verificou -se que o gene da GH é muito polimórfico, tendo sido encontrados polimorfismos específicos em algumas das raças. Os resultados sugerem que os polimorfismos do gene da GH, entre outros (e.g., nas caseínas), poderão vir a ser utilizados na seleção assistida por marcadores genéticos, de modo a melhorar da produção de leite sem afetar a sua qualidade. Contudo, a resposta à seleção será sempre condicionada pela prática de um correto maneio alimentar dos animais.

An integrated and comparative approach to genetic selection of the aquaculture species Dicentrarchus labrax

The European sea bass, Dicentrarchus labrax, is one of the most important marine species cultivated in Southern Europe and has not benefited from selective breeding. One of the major goals in the sea bass (D. labrax) aquaculture industry is to understand and control the complexity of growth associated traits. The aim of the methodology developed for the studies reported in the thesis was not only to establish genetic and genomic resources for sea bass, but to also develop a conceptual strategy to efficiently create knowledge in a research environment that can easily be transferred to the aquaculture industry. The strategy involved; i) establishing an annotated sea bass transcriptome and then using it to, ii) identify new genetic markers for target QTL regions so that, iii) new QTL analysis could be performed and marker based resolution of the DNA regions of interest increased, and then iv) to merge the linkage map and the physical map in order to map the QTL confidence intervals to the sea bass genome and identify genes underlying the targeted traits. Finally to test if genes in the QTL regions that are candidates for divergent growth phenotypes have modified patterns of transcription that reflects the modified whole organism physiology SuperSAGE-SOLiD4 gene expression was used with sea bass with high growth heterogeneity. The SuperSAGE contributed to significantly increase the transcriptome information for sea bass muscle, brain and liver and also led to the identification of putative candidate genes lying in the genomic region of growth related QTL. Lastly all differentially expressed transcripts in brain, liver and muscle of the European sea bass with divergent specific growth rates were mapped to gene pathways and networks and the regulatory pathways most affected identified and established the tissue specific changes underlying the divergent SGR. Owing to the importance of European sea bass to Mediterranean aquaculture and the developed genomics resources from the present thesis and from other studies it should be possible to implement genetic selection programs using marker assisted selection.

Role of Ccbe1 during cardiac differentiation of mouse ESCs

Tese de Doutoramento, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2016

Identificação de marcadores moleculares ligados a um gene mutado de resistência ao oídio (Erysiphe pisi Syd.) em ervilha (Pisum sativum L.)

Tese dout., Ciências Agrárias, Universidade do Algarve, 2006

Aplicação de algoritmos genéticos na optimização de secções de vigas de betão armado

A generalidade dos problemas de ordem prática no domínio do dimensionamento das estruturas incluem variáveis discretas. Os métodos matemáticos tradicionais apresentam dificuldades na procura dos óptimos globais em problemas não lineares discretos. Os algoritmos genéticos constituem uma heurística eficaz na optimização de sistemas estruturais que envolvem variáveis discretas e contínuas. No presente trabalho, descreve-se uma metodologia que visa a optimização da forma geométrica da secção, do dimensionamento e colocação das armaduras em vigas de betão armado, com recurso a algoritmos genéticos. Apresenta-se um exemplo de aplicação da metodologia proposta.

Estudo da variabilidade genética de marcadores moleculares ligados ao gene da MGP e sua aplicação para paternidades em Sparus aurata

Dissertação de Mestrado, Biologia Marinha, Especialização em Biotecnologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2008

Protecção e avaliação de marcadores do stress foto-oxidativo em Ceratonia siliqua L. e Tuberaria major (Willk) P. Silva & Rozeira sob altas temperaturas e défice hídrico

Dissertação mest., Engenharia Biológica, Universidade do Algarve, 2009

Identification of novel molecular determinants of tissue mineralization in fish

The identification of genes involved in signaling and regulatory pathways, and matrix formation is paramount to the better understanding of the complex mechanisms of bone formation and mineralization, and critical to the successful development of therapies for human skeletal disorders. To achieve this objective, in vitro cell systems derived from skeletal tissues and able to mineralize their extracellular matrix have been used to identify genes differentially expressed during mineralization and possibly new markers of bone and cartilage homeostasis. Using cell systems of fish origin and techniques such as suppression subtractive hybridization and microarray hybridization, three genes never associated with mechanisms of calcification were identified: the calcium binding protein S100-like, the short-chain dehydrogenase/reductase sdr-like and the betaine homocysteine S-methyltransferase bhmt3. Analysis of the spatial-temporal expression of these 3 genes by qPCR and in situ hybridization revealed: (1) the up-regulation of sdr-like transcript during in vitro mineralization of gilthead seabream cell lines and its specificity for calcified tissues and differentiating osteoblasts; (2) the up-regulation of S100-like and the down-regulation of bhmt3 during in vitro mineralization and the central role of both genes in cartilaginous tissues undergoing endo/perichondral mineralization in juvenile fish. While expression of S100-like and bhmt3 was restricted to calcified tissues, sdr-like transcript was also detected in soft tissues, in particular in tissues of the gastrointestinal tract. Functional analysis of gene promoters revealed the transcriptional regulation of the 3 genes by known regulators of osteoblast and chondrocyte differentiation/mineralization: RUNX2 and RAR (sdr-like), ETS1 (s100-like; bhmt3), SP1 and MEF2c (bhmt3). The evolutionary relationship of the different orthologs and paralogs identified within the scope of this work was also inferred from taxonomic and phylogenetic analyses and revealed novel protein subfamilies (S100-like and Sdr-like) and the explosive diversity of Bhmt family in particular fish groups (Neoteleostei). Altogether our results contribute with new data on SDR, S100 and BHMT proteins, evidencing for the first time the role for these three proteins in mechanisms of mineralization in fish and emphasized their potential as markers of mineralizing cartilage and bone in developing fish.

Identification of regulatory polymorphisms associated with breast cancer risk

Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2014

Estudo de polimorfismos genéticos e da sua associaçäo com capacidades de produçäo leiteira em caprinos de raça Algarvia e ovinos de raça Serra da Estrela

Dissertação de mest. em Química Celular, Unidade de Ciências Exactas e Humanas, Univ. do Algarve, 1996