Estudo biométrico do caranguejo-de-profundidade de Angola (Chaceon maritae) e determinação do tamanho de primeira maturação sexual

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

11-ketotestosterone inhibits the alternative mating tactic in sneaker males of the peacock blenny, Salaria pavo

In the peacock blenny, Salaria pavo, a species with courtship sex-role reversal, smaller, younger males mimic the courtship behavior and the nuptial coloration of females in order to get access to nests during spawning and to parasitize egg fertilization from nest-holder males. Later in their life, sneakers transform both morphologically and behaviorally into nest-holder males. In the present paper we investigate the activational role of 11-ketotestosterone (KT), the most potent androgen in most teleost species, to promote the switch between tactics in sneaker males of S. pavo. Sneakers were implanted either with KT or with control (i.e. castor oil) silastic implants. A week after implantation they were subjected to a set of behavioral tests and morphometric measurements. KT treatment promoted the differentiation of secondary sex characters, such as the anal glands, and inhibited the expression of female courtship behavior. KT-treated sneakers also showed a trend toward less frequent display of female nuptial coloration. There was no effect of KT treatment on the expression of typical nest-holder male behavior. Finally, there was no effect of KT treatment on the number or soma size of arginine vasotocin neurons in the preoptic area, which are often associated with the expression of vertebrate sexual behavior. Thus, KT seems to play a key role in mating tactic switching by inhibiting the expression of female courtship behavior and by promoting the development of male displaying traits (e.g. anal glands). The lack of a KT effect on behavior typical of nest-holding males and vasotocinergic preoptic neurons suggests that a longer time frame or other endocrine/social signals are needed for the initiation of these traits in males that are switching tactics.

Ligand binding and signalling pathways of PTH receptors in sea bream (Sparus auratus) enterocytes

Whole animal studies have indicated that Ca2+ uptake by the gastrointestinal tract is regulated by the action of parathyroid hormone-related peptide (PTHrP) in teleost fish. We have characterised PTH receptors (PTHR) in piscine enterocytes and established, by using aminoterminal PTHrP peptides, the amino acid residues important for receptor activation and for stabilising the ligand/receptor complex. Ligand binding of 125I-(1–35tyr) PTHrP to the membrane fraction of isolated sea bream enterocytes revealed the existence of a single saturable high-affinity receptor (KD=2.59 nM; Bmax=71 fmol/mg protein). Reverse transcription/polymerase chain reaction with specific primers for sea bream PTH1R and PTH3R confirmed the mRNA expression of only the later receptor. Fugu (1–34) PTHrP increased cAMP levels in enterocytes but had no effect on total inositol phosphate accumulation. The aminoterminal peptides (2–34)PTHrP, (3–34)PTHrP and (7–34) PTHrP bound efficiently to the receptor but were severely defective in stimulating cAMP in enterocyte cells indicating that the first six residues of piscine (1–34)PTHrP, although not important for receptor binding, are essential for activation of the adenylate cyclase/phosphokinase A (AC-PKA)-receptor-coupled intracellular signalling pathway. Therefore, PTHrP in teleosts acts on the gastrointestinal tract through PTH3R and the AC-PKA intracellular signalling pathway and might regulate Ca2+ uptake at this site. Ligand-receptor binding and activity throughout the vertebrates appears to be allocated to the same amino acid residues of the amino-terminal domain of the PTHrP molecule.

Identification and molecular characterization of bone-related micrornas: functional implications

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

Controle hormonal da diferenciação e inversão sexual na dourata Sparus aurata (L.)

Tese de Doutoramento, Biologia Marinha, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Universidade do Algarve, 2001

Papéis de género, homofobia internalizada e autoestima sexual numa amostra de lésbicas e gays

Dissertação de mestrado, Psicologia (Psicologia Clínica e da Saúde), Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, 2015

Seleção sexual e estimativa populacional em Syngnathus typhle na Ria Formosa (Portugal)

Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Investigating the role of Annexin A2 in Epidermal Growth Factor (EGF) induced signalling in cancer

Dissertação de mestrado, Qualidade em Análises, Faculdade de Ciências e Tecnologia, Universidade do Algarve; Universitat de Barcelona; Gdansk University of Technology, Universidad de Cádiz, Universitas Bergensis; 2015