Browsing by Author "Castro, L. Filipe C."
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- Dietary creatine supplementation in gilthead seabream (Sparus aurata) increases dorsal muscle area and the expression of myod1 and capn1 genesPublication . Ramos-Pinto, Lourenço; Lopes, Graciliana; Sousa, Vera; Castro, L. Filipe C.; Schrama, Denise; Rodrigues, Pedro; Valente, Luísa M. P.Creatine (Cr) is an amino acid derivative with an important role in the cell as energy buffer that has been largely used as dietary supplement to increase muscle strength and lean body mass in healthy individuals and athletes. However, studies in fish are scarce. The aim of this work is to determine whether dietary Cr supplementation affects muscle growth in gilthead seabream (Sparus aurata) juveniles. Fish were fed ad libitum for 69 days with diets containing three increasing levels of creatine monohydrate (2, 5, and 8%) that were compared with a non-supplemented control (CTRL) diet. At the end of the trial, the fast-twist skeletal muscle growth dynamics (muscle cellularity) and the expression of muscle-related genes were evaluated. There was a general trend for Cr-fed fish to be larger and longer than those fed the CTRL, but no significant differences in daily growth index (DGI) were registered among dietary treatments. The dorsal cross-sectional muscle area (DMA) of fish fed Cr 5 and Cr 8% was significantly larger than that of fish fed CTRL. The groups supplemented with Cr systematically had a higher relative number of both small-sized (<= 20m mu) and large-sized fibers (>= 20)mu m). Dorsal total fibers number was highest in fish fed 5% Cr. In fish supplemented with 5% Cr, the relative expression of myogenic differentiation 1 (myod1) increased almost four times compared to those fed the CTRL diet. The relative expression of calpain 3 (capn3) was highest in fish fed diets with 2% Cr supplementation, but did not differ significantly from those fed the CTRL or Cr 5%. The myod1 gene expression had a positive and significant correlation with that of capn1, capnsla, and capn3 expression. These results suggest that the observed modulation of gene expression was not enough to produce a significant alteration in muscle phenotype under the tested conditions, as a non-significant increase in muscle fiber diameter and higher total number of fiber was observed, but still resulted in increased DMA. Additional studies may be required in order to better clarify the effect of dietary Cr supplementation in fish, possibly in conjunction with induced resistance training.
- Extensive gene loss parallels kidney aglomerulism in SyngnathidaePublication . Pinto, Bernardo; Machado, André M.; Cordeiro, J. Miguel; Kolbadinezhad, Salman Malakpour; Fonseca, Elza; Andrade, Jose; Palma, Jorge; Ruivo, Raquel; Monteiro, Nuno; Wilson, Jonathan M.; Castro, L. Filipe C.The eccentric seahorses, seadragons, pipehorses and pipefishes (Syngnathidae) have an aglomerular kidney1. Here, we show that nephron genes2 conserved in Bilateria are secondarily eroded/deleted in Syngnathidae genomes. A transcriptome enrichment analysis suggests the predominance of excretion processes in the Syngnathidae kidney. In a lineage where crypsis and idleness are tightly associated, we propose that aglomerulism evolved as an energy-saving strategy.
- Statins: an undesirable class of aquatic contaminants?Publication . Santos, Miguel M.; Ruivo, Raquel; Lopes-Marques, Mónica; Torres, Tiago; de los Santos, Carmen B.; Castro, L. Filipe C.; Neuparth, TeresaEmerging pollutants, such as pharmaceuticals, may pose a considerable environment risk. Hypocholesterolaemic drugs such as statins are among the most prescribed human pharmaceuticals in western European countries. In vertebrates, this therapeutic class disrupts the cholesterol synthesis by inhibiting the enzyme 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), responsible for the limiting step in the mevalonate pathway. Recently, functional studies have shown that statins competitively inhibit HMGR in vertebrates and arthropods, two taxa that have diverged over 450 million years ago. Importantly, chronic simvastatin exposure disrupts crustacean reproduction and development at environmentally relevant concentrations. Hence, a fundamental question emerges: what is the taxonomic scope of statins-induced HMGR inhibition across metazoans? Here, we address this central question in a large sampling of metazoans using comparative genomics, homology modelling and molecular docking. Sequence alignment of metazoan HMGRs allowed the annotation of highly conserved catalytic, co-factor and substrate binding sites, including residues highjacked for statin binding. Furthermore, molecular docking shows that the catalytic domains of metazoan HMGRs are highly conserved regarding interactions, not only with HMG-CoA, but also with both simvastatin and atorvastatin, the top prescribed statins in Europe and USA. Hence, the data indicates that both statins are expected to competitively inhibit metazoan’s HMGRs, and therefore all metazoan taxa might be at risk. The environmental relevance of these findings are discussed and research priorities established. We believe that the conceptual framework used in this study can be applied to other emerging pollutants and assist in the design of toxicity testing and risk assessment.
- The complete mitochondrial genome of the endemic Iberian pygmy skate Neoraja iberica Stehmann, Séret, Costa, & Baro 2008 (Elasmobranchii, Rajidae)Publication . Gomes-dos-Santos, André; Machado, André M.; Graça Aranha, Sofia; Dias, Ester; Veríssimo, Ana; Castro, L. Filipe C.; Froufe, ElsaSkates, Chondrichthyes fishes from order Rajiformes, are the most species-rich group of all Batoidea. However, their phylogenetic relationships and systematics is still a highly discussed and controversial subject. The use of complete mitogenome has shown to be a promising tool to fill this gap of knowledge. Here, the complete mitogenome of the Iberian pygmy skate Neoraja iberica (Stehmann, Séret, Costa & Baro 2008) was sequenced and assembled. The mitogenome is 16,723 bp long and its gene content (i.e. 13 protein-coding genes, 22 transfer RNA, and 2 ribosomal RNA genes) and arrangement are the expected for Batoidea. Phylogenetic reconstructions, including 89 Rajiformes and two outgroup Rhinopristiformes, recovered family Rajidae as monophyletic, and further divided in the monophyletic tribe Rajini, sister to tribes Amblyrajini and Rostrorajini. The newly sequenced N. iberica mitogenome is the first representative of the tribe Rostrorajini.
- Trophic ecology of common bottlenose dolphins in a pelagic insular environment inferred by stable isotopesPublication . Dias, Ester; Dromby, Morgane; Ferreira, Rita; Gil, Ágatha; Tejerina, Raquel; Castro, L. Filipe C.; Rosso, Massimiliano; Sousa-Pinto, Isabel; Hoffman, Joel C.; Teodosio, Maria; Dinis, Ana; Alves, FilipeThe common bottlenose dolphin (Tursiops truncatus) is a top marine predator widely dispersed in coastal and pelagic habitats and with a generalist feeding behavior. Yet, information on the trophic ecology of animals inhabiting pelagic environments is still scarce. Using carbon (& delta;C-13: C-13/C-12) and nitrogen (& delta;N-15: N-15/N-14) stable isotope ratios, we identified and quantified the main groups of prey assimilated by bottlenose dolphins inhabiting an oceanic habitat (Madeira Island, East Atlantic). Bottlenose dolphins assimilated pelagic, schooling fish (such as blue jack mackerel, Trachurus picturatus) and mesopelagic and demersal squids, which reinforces the pelagic dietary composition of insular/oceanic dolphins. Also, intra-seasonal differences were found in their stable isotope ratios, which suggest intraspecific variability in the feeding behavior among individuals living in the same area. Sex was not the main factor contributing to these differences, suggesting the lack of trophic niche segregation between adult males and females in this offshore environment. Nonetheless, further studies including different life stages and information on the ecophysiological requirements are necessary to disclose the factors responsible for the observed variability. This study showed that insular dolphins fed primarily on economically important pelagic prey, highlighting the need of developing management strategies that integrate conservation in fisheries plans.