Functional genomics in fish : towards understanding stress and immune responses at a molecular level /

Consultable des del TDXTítol obtingut de la portada digitalitzadaAquesta tesis doctoral està basada en estudiar la resposta immunològica dels peixos en models d'estrès i d'activació del sistema immune des la genòmica funcional. L'aplicació de tecnologies moleculars com el Differential Display van permetre identificar y clonar por primera vegada en orades (Sparus aurata) y en altres especies de peix, el gen enolasa. Aquest enzim glucolític s'ha plantejat per primera vegada com un bon marcador molecular per estudiar el benestar dels peixos. Per mitjà de l'ús d'una plataforma de microarrays dissenyada específicament per a salmònids, i altres metodologies biomoleculars, es va comprovar que els nivells d'enolasa eren regulats en diferents teixits y en diferents especies de peix, com també en adverses situacions per l'animal. D'altra banda, s'han estudiat diferents gens immunològics candidats a ser possibles gens per l'estudi del sistema immunològic dels peixos. Aquests gens s'han estudiat a nivell d'expressió en teixits de truites (Oncorhynchus mykiss) mitjançant PCR convencional i PCR quantitativa, i l'ús de metodologies biomoleculars i bioinformàtiques. Entre ells, destaca el factor de transcripció PU.1, un gen indispensable per el desenvolupament de l'hematopoesi. Aquest gen, s'ha clonat i caracteritzat per primera vegada en salmònids. L'expressió de PU.1 s'ha estudiat mitjançant l'ús d'hibridacions in situ en ronyó anterior y en cervell de truita. A més, l'ús de microarray en aquest dos teixits han permès fer un estudi exhaustiu i pioner a nivell de transcriptòmica en peixos. Les anàlisis del xip de microarray, ha revelat que grups de gens s'activen o s'inhibeixen com a conseqüència d'un estrès immunològic. En resum, aquesta tesis doctoral ha aplicat el desenvolupament de noves tecnologies moleculars pioneres en peixos, com el microarray, la clonació de noves seqüències gèniques i la bioinformàtica, per estudiar la genòmica funcional dels peixos en situacions d'activació dels mecanismes d'estrès i del sistema immune.The main results of the present thesis can be integrated to a better understanding the stress and the immune responses in fish at a transcriptional level. The application of functional genomic tools, which encloses from using simple PCR analysis to more modern, sophisticate and fashionable microarray technique, allowed us to identified transcriptional regulations of certain set of genes which are enhanced or repressed under stress conditions. Our findings contribute to increase knowledge of molecular mechanism involved in coping the stress and immune responses in fish and provides a better understanding of fish physiology when fish health is threatened. Furthermore, thesis results may be interesting for aquaculture which looks for good biomolecular markers that may improve fish production and fish quality. The isolation, characterization and gene expression study with further microarray analysis of the enolase gene, allowed us to describe enolase as a possible biomolecular marker to determine fish welfare. The in situ hybridization study of the hematopoietic transcription factor PU.1, contributed to amplify the knowledge of the development of the fish immune system. Throughout this thesis, DNA sequences and mRNA expression levels of several genes studied, have contributed to enlarged genomic fish database. In summary, this thesis described from a transcriptional level, gene expression and molecular mechanisms activated or repressed when fish welfare is threatened and contributes to a better understanding of transcriptiomic mechanisms required to cope with the stress

Towards a Transnational Civil Society : Actors and Concepts in Europe from the Late Eighteenth to the Twentieth Century

Since late eighteenth-century Enlightenment, the concept of civil society has increasingly assumed a transnational dimension that has given rise to political debates and attracted scholarly interest. This paper provides a research report and a historical overview of the emergence and transformation of civil society organizations that have transcended national borders and cultural boundaries, especially International Non-Governmental Organizations. Based on deliberations about the definition and conceptualization of ‘transnational civil society’, the investigation concentrates on the abolitionists, the workers’ organizations as well as on peace and on women’s movements. The authors suggest that further historical studies of transnational civil society should relate its groups and activists to specific contexts and conditions. They also argue that further research should pay particular attention to the actors of transnational civil society, their performance and representations. Overall, static conceptions of transnational civil society have ignored its flexibility and changeability over the course of the last two centuries.Seit der Aufklärung im späten 18. Jahrhundert hat der Begriff Zivilgesellschaft eine zunehmend transnationale Dimension erreicht, die insbesondere politische Diskussionen und wissenschaftliches Interesse auslöste. Das vorliegende Diskussionspapier lässt sich als Forschungsbericht verstehen, der einen historischen Überblick über Auftreten und Transformation zivilgesellschaftlicher Organisationen gibt, die insbesondere national und kulturell grenzüberschreitend institutionalisiert sind, wie beispielsweise internationale Nichtregierungsorganisationen. Auf der Grundlage einer sorgfältigen Analyse von Definition und Konzeption ‚transnationaler Zivilgesellschaft’, konzentriert sich die Untersuchung vor allem auf die Gegner der Todesstrafe, aber auch Gewerkschaften sowie Friedens- und Frauenbewegungen. Beide Autoren plädieren für eine Auseinandersetzung mit der Thematik aus historischer Perspektive, um insbesondere bestimmte Gruppen und Aktivisten in direkten Bezug zu ihrem historischen Kontext und Vorbedingungen zu stellen. Darüber hinaus heben sie hervor, dass daran anknüpfende Studien gerade den Akteuren, ihrem Auftreten und ihrer Präsentation gewidmet werden sollen. Im Gesamtzusammenhang lässt sich festhalten, dass die bisher eher statisch geprägten Untersuchungen zum Forschungsschwerpunkt ‚transnationale Zivilgesellschaft’ insbesondere die Flexibilität und Unbeständigkeit derselbigen in den letzten beiden Jahrhunderten nicht berücksichtigten

Response of sea bream to handling

Understanding how gilthead sea bream, Sparus aurata L., an important Mediterranean Sea species for aquaculture, respond physiologically to stressors commonly encountered in intensive rearing is important for eiective production, as managing for stress is a major factor in maintaining healthy ¢sh stocks. Our objective was to determine whether holding juvenile gilthead sea bream at a high density (HD), as a chronic stressor, would aiect their physiological responses to a subsequent acute handling stressor. After acclimation at a low density (LD) of 6k g m 3 in 200-L circular tanks containing 33^ 36 g L 1 recirculating seawater at 191C under a normal photoperiod, juvenile 37-g gilthead sea bream were con¢ned for 14 days at a HD of 26 kg m 3 an

DNA Methylation of the Gonadal Aromatase (cyp19a) Promoter Is Involved in Temperature-Dependent Sex Ratio Shifts in the European Sea Bass

15 pages, 9 figures, 1 tableTemperature changes during early embryonic and/or larval stages are able to modify sex ratios in fish and reptiles. However, the underlying mechanism by which temperature is able to modify the molecular pathways that developing gonads follow to become ovaries or testes is still unknown. One of the most interesting questions raised from previous studies with our model species, the European sea bass, was how temperature could affect the developmental fate of the gonads at a time when they were not even formed in the most rudimentary manner. This was the telltale sign of an epigenetic mechanism. In this study, DNA methylation levels of the aromatase promoter were analyzed in European sea bass exposed to different temperatures during early developmental stages. Aromatase is the enzyme that converts androgens (male hormones) into estrogens (female hormones), which are essential for ovarian development in all non-mammalian vertebrates. We show that increased temperature during a critical period in early development is able to increase DNA methylation of the aromatase promoter, preventing aromatase gene expression. We conclude that gonadal aromatase promoter methylation is most likely part of the long-sought-after mechanism connecting temperature and environmental sex determination in vertebratesLN-M and ND were supported by predoctoral scholarships and JV and LR by postdoctoral grants from the Spanish Ministry of Science and Innovation (MCINN). Research was funded by MCINN projects “Sexgene” (AGL2006-01359), “Aquagenomics” (CDS2007-0002), and “Epigen-Aqua” (AGL2010-15939) to FP and by MICINN project BFU2010-18692 and AGAUR grant to LDC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewe

L'Ús dels esclerocis de Claviceps purpurea dins la medicina popular andorrana

Es reporta l'ús del Claviceps purpurea (Fr.) Tul. en la medicina tradicional d'Andorra i l'Alt Urgell, segons les dades de diversos informants, que esmenten que era emprat per les llevadores. Aquest ús sembla estar lligat a un coneixement expert per part de les persones especialitzades en obstetríciaThe use of the Claviceps purpurea (Fr) Tulle. is reported from the traditional medicine of Andorra and the Alt Urgell according to information of some interviewed people during our study of the ethnobotany of Andorra. This fungi was used by midwifes and seems to be restricted to the people specialized in obstetrics of the traditional society

Analysis of some economic-financial ratios to analyse the financial crisis in five-star hotels in Barcelona and Madrid

Purpose: Analyse some of the financial ratios to see the impact of the economic crisis on 5-star hotels in Spain. Design/methodology: The information needed to write this article was taken from the Iberian Balance Sheet Analysis System (SABI), the Hotel Occupancy Survey published periodically by the National Statistics Institute, the IDESCAT and the official websites of the hotels analysed. Findings: The results obtained show how the financial crisis did not have a direct impact on luxury hotels, but on the contrary, they continue to increase their success thanks to the best continuous strategies. One test is the luxury hotels that were created in Barcelona and Madrid between 2008 and 2011. The work shows that it does not take into account for a hotel chain to have more than one luxury hotel in the same city, since one both of them may end up showing financial losses. It is also found that it is important to determine the number of rooms that the hotel must have in order to avoid construction costs and to have the maximum efficiency. Research limitations/implications: The study has the problem of not updating the SABI database. In some cases, the information has not been updated since 1990. Practical implications: The result that luxury hotels can cover the fixed assets coefficient with their equity. At the same time, it supports the importance of making a better forecast of the number of rooms in order to help them have a better financing. Social implications: It supports the importance of a single luxury hotel in the same hotel chain in the same city and of making good strategic planning in order to improve the results of financial ratios. Originality/value: The article helps explain how the tourist model in Spain has changed since the beginning of the financial crisis.Peer Reviewe

Heat-induced masculinization in domesticated zebrafish is family-specific and yields a set of different gonadal transcriptomes

Understanding environmental influences on sex ratios is important for the study of the evolution of sex-determining mechanisms and for evaluating the effects of global warming and chemical pollution. Fishes exhibit sexual plasticity, but the underlying mechanisms of environmental effects on their reproduction are unclear even in the well-established teleost research model, the zebrafish. Here we established the conditions to study the effects of elevated temperature on zebrafish sex. We showed that sex ratio response to elevated temperature is family-specific and typically leads to masculinization (female-to-male sex reversal), resulting in neomales. These results uncovered genotype-by-environment interactions that support a polygenic sex determination system in domesticated (laboratory) zebrafish. We found that some heat-treated fish had gene expression profiles similar to untreated controls of the same sex, indicating that they were resistant to thermal effects. Further, most neomales had gonadal transcriptomes similar to that of regular males. Strikingly, we discovered heat-treated females that displayed a normal ovarian phenotype but with a “male-like” gonadal transcriptome. Such major transcriptomic reprogramming with preserved organ structure has never been reported. Juveniles were also found to have a male-like transcriptome shortly after exposure to heat. These findings were validated by analyzing the expression of genes and signaling pathways associated with sex differentiation. Our results revealed a lasting thermal effect on zebrafish gonads, suggesting new avenues for detection of functional consequences of elevated temperature in natural fish populations in a global warming scenario

Hypergravity induces changes in physiology, gene expression and epigenetics in zebrafish

All living organisms that inhabit Earth have evolved under a common value of gravity, which amounts to an acceleration of 9.81 m/s2 at mean sea level. Changes on it could cause important alterations that affect vital biological functions. The crescent interest in spatial exploration has opened the question of how exactly these changes in gravity would affect Earth life forms on space environments. This work is the result of a collaborative co-supervision of a master thesis between experts in the area of space sciences and biology, and it can serve as a case study for training experts in such interdisciplinary environments. In particular, we focus on the effect of gravity as a pressure factor in the development of zebrafish (Danio rerio) in the larval stage as a model organism using up-to-date (genomic and epigenetic) techniques. Given the high cost of any experiment in true low gravity (which would require a space launch), we performed an initial experiment in hypergravity to develop the methodologies and identify good (epi)genetic markers of the effect of gravity in our model organism. Previous studies in zebrafish have shown how alteration in gravity effects the development and the gene expression of important regulatory genes. For this study, we firstly customized a small laboratory scale centrifuge to study changes in fish physiology together with changes at molecular levels. We exposed zebrafish larvae from 0 to 6 days post fertilization to the simulated hypergravity (SHG) (100 rpm 3g). After 6 days of hypergravity exposition the larvae showed changes in their swimming and flotation patterns, and presented corporal alterations. Then, we assessed gene expression of genes implicated in important biological processes, (e.g., epigenetics), and an upregulation were observed when compared to the control. Taken together, these preliminary findings show how gravity alterations could affect some basic biological responses, and illustrate the potential of developing new science cases to be developed by students at postgraduate level (MSc and beyond) in a multidisciplinary environmen

Comparative analysis of the acute response of the trout, O. mykiss, head kidney to in vivo challenge with virulent and attenuated infectious hematopoietic necrosis virus and LPS-induced inflammation

Background: The response of the trout, O. mykiss, head kidney to bacterial lipopolysaccharide (LPS) or active and attenuated infectious hematopoietic necrosis virus (IHNV and attINHV respectively) intraperitoneal challenge, 24 and 72 hours post-injection, was investigated using a salmonid-specific cDNA microarray. Results: The head kidney response to i.p. LPS-induced inflammation in the first instance displays an initial stress reaction involving suppression of major cellular processes, including immune function, followed by a proliferative hematopoietic-type/biogenesis response 3 days after administration. The viral response at the early stage of infection highlights a suppression of hematopoietic and protein biosynthetic function and a stimulation of immune response. In fish infected with IHNV a loss of cellular function including signal transduction, cell cycle and transcriptional activity 72 hours after infection reflects the tissue-specific pathology of IHNV infection. attIHNV treatment on the other hand shows a similar pattern to native IHNV infection at 24 hours however at 72 hours a divergence from the viral response is seen and replace with a recovery response more similar to that observed for LPS is observed. Conclusion: In conclusion we have been able to identify and characterise by transcriptomic analysis two different types of responses to two distinct immune agents, a virus, IHNV and a bacterial cell wall component, LPS and a 'mixed' response to an attenuated IHNV. This type of analysis will lead to a greater understanding of the physiological response and the development of effective immune responses in salmonid fish to different pathogenic and pro-inflammatory agents

Micromechanical properties of yttria-doped zirconia ceramics manufactured by direct ink writing

Yttria-doped zirconia ceramics have many applications in a wide range of industries mainly due to their excellent mechanical properties, corrosion resistance and biocompatibility. In this study, micromechanical properties of yttria-doped zirconia produced by Direct-Ink Writing (DIW) were investigated and compared to the ones produced by Cold Isostatic Pressing (CIP). In doing so, mechanical response was assessed at different length scales, from macro- up to submicrometric-, by means of Vickers hardness, nanoindentation, and nanoscratch tests. Microstructure was also characterized by determining grain size, crystal structure and phase tetragonal to monoclinic phase transformation. Results revealed that printed samples displayed 20–25% lower hardness values compared to those exhibited by the respective CIP pairs. Differences in hardness between 3 and 8 mol% yttria content evaluated for CIP samples were slight for printed samples, due to the effect of microstructural defects like porosity, resulting from the processing parameters used. At the local level, such an effect was found to be lower. In this sense, hardness and elastic modulus achieved by nanoindentation were closer, when comparing printed and CIP samples. Scratch tests carried out from 0 to 250 mN revealed that 3 mol% Y2O3 samples developed micro-fracture events in the track length, being the printed samples the ones heavily deformed.Peer ReviewedPostprint (author's final draft