Transcriptomics Responses in Marine Diatom Thalassiosira pseudonana Exposed to the Polycyclic Aromatic Hydrocarbon Benzo[a]pyrene

Diatoms are unicellular, photosynthetic, eukaryotic algae with a ubiquitous distribution in water environments and they play an important role in the carbon cycle. Molecular or morphological changes in these species under ecological stress conditions are expected to serve as early indicators of toxicity and can point to a global impact on the entire ecosystem. Thalassiosira pseudonana, a marine diatom and the first with a fully sequenced genome has been selected as an aquatic model organism for ecotoxicological studies using molecular tools. A customized DNA microarray containing probes for the available gene sequences has been developed and tested to analyze the effects of a common pollutant, benzo(a)pyrene (BaP), at a sub-lethal concentration. This approach in diatoms has helped to elucidate pathway/metabolic processes involved in the mode of action of this pollutant, including lipid metabolism, silicon metabolism and stress response. A doseresponse of BaP on diatoms has been made and the effect of this compound on the expression of selected genes was assessed by quantitative real time-PCR. Up-regulation of the long-chain acyl-CoA synthetase and the anti-apoptotic transmembrane Bax inhibitor, as well as down-regulation of silicon transporter 1 and a heat shock factor was confirmed at lower concentrations of BaP, but not the heat-shock protein 20. The study has allowed the identification of molecular biomarkers to BaP to be later on integrated into environmental monitoring for water quality assessment.JRC.H.1-Water Resource

Development of the First Watch List under the Environmental Quality Standards Directive

According to Directive 2008/105/EC (the Environmental Quality Standards Directive, EQSD), a new mechanism is needed to provide high-quality monitoring information on the concentrations of polluting substances in the aquatic environment across the EU. The aim of this mechanism is to support the identification of priority substances for regulation under the Water Framework Directive. A restricted number of substances (up to 10) are to be included in a dynamic Watch List, remaining there for limited time. Three compounds, i.e. diclofenac, 17-beta-estradiol (E2), and 17-alpha-ethinylestradiol (EE2) have already been identified for inclusion in the first Watch List, for the specific purpose of better informing the determination of suitable risk reduction measures. Therefore, up to seven additional substances should be identified for inclusion. This report describes the procedure to identify a short-list of substances, based on the suspected risk to or via the aquatic environment, as well as on the unavailability of sufficient monitoring data or data of sufficient quality to identify the risk posed by those substances, and to prioritise them at EU level. From the short-list, seven additional substances are proposed for inclusion in the first Watch List.JRC.H.1-Water Resource

EU Wide Monitoring Survey on Waste Water Treatment Plant Effluents

In the year 2010, effluents from 90 European waste water treatment plants (WWTPs) were collected and analysed in total for 160 organic chemicals and 20 inorganic trace elements. The analyses were complemented by applying also effect-based monitoring approaches aiming at estrogenicity and dioxin-like toxicity analysed by in vitro reporter gene bioassays, and yeast and diatom culture acute toxicity optical bioassays. The analytical work was performed in six European expert laboratories. This European-wide monitoring study on the occurrence of micropollutants in WWTP effluents represents the largest EU wide monitoring survey on WWTP effluents ever performed. It produced a comprehensive data set on many so far only locally investigated “emerging” compound classes including pharmaceuticals and personal care products (PPCPs), veterinary (antibiotic) drugs, perfluoroalkyl substances (PFASs), organophosphate ester flame retardants, pesticides (and some metabolites) or industrial chemicals such as benzotriazoles (corrosion inhibitors), polycyclic musk fragrances, x-ray contrast agents, Gadolinium compounds, and siloxanes. The obtained results show the presence of 131 target organic compounds in European wastewater effluents, in concentrations ranging from low nanograms to milligrams per liter. These results obtained from 90 different European WWTPs allow the calculation of a European median level for the chemicals investigated. The most relevant compounds identified in the effluent water samples in terms of frecquency of detection, maximum, average and median concentration levels were Sucralose, Acesulfame K (artificial sweeteners), PFOA, PFHxA, PFHpA, PFOS (perfluoroalkyl substances), N,N’-Diethyltoluamide (DEET; insect repellent), Benzotriazoles (corrosion inhibitors), the pharmaceuticals Bisoprolol, Carbamazepine, Ciprofloxacine, Citaprolam, Clindamycine, Codeine, Diltiazem, Diphenhydramin, Eprosartan, Fexofenadine, Flecainide, Gemfibrozil, Fluconazole, Haloperidol, Ibersartan, Ibuprofen, Ketoprofen, Oxazepam, Risperidone, Sulfamethoxazole, Telmisartan, Tramadol, Trimethoprim, Venlafaxin, the organo-phosphate ester flame retardants Tri-iso-butylphosphate (TIBP), Tributylphosphate (TBP), Tris(2-chloroethyl)phosphate (TCEP), Tris(2-chloroisopropyl)phosphate (TCPP), Tris(2-butoxyethyl)phosphate (TDCP), Tris(2-butoxyethyl)phosphate (TBEP), Triphenyl-phosphate (TPP), 2-Ethylhexyldiphenyl-phosphate (EHDPP), the x-ray contrast media Amidotrizoic acid, Iohexol, Iopromid, Iomeprol, Iopamidol, the pesticides Terbutylazine, Terbutylazine-desethyl (metabolite), MCPA, Mecoprop, Diuron, Triclosan (antibacterial), and Gadolinium (from magnetic resonance imaging contrast media used in hospitals).JRC.H.1-Water Resource

Background and common lesions in the female reproductive organs of giant anteaters (Myrmecophaga tridactyla)

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species in South America and is considered endangered or near extinction in Central America. Therefore, studies describing the reproductive characteristics of this species are pivotal for its conservation. Thus, this study aimed to provide a morphological description of the female reproductive tissues of this species. We collected tissue samples from six female giant anteaters and performed gross, morphological, and histochemical analyses. Five adult subjects and one juvenile were included in the study. In the ovary, classifications were made according to the follicle and oocyte sizes: primordial, primary, secondary, early antral, or antral. Typical follicles with a single oocyte surrounded by a simple or stratified layer of cubic epithelium, atretic follicles, corpora lutea, corpora albicans, and ovarian cysts were also observed. No ovarian lesions were observed. By contrast, endometritis, metritis, mucometra, and endometrial cysts were identified in the uterus. Uterine alterations in these subjects were frequent and could affect reproduction

Biochemical and biophysical studies on human phaenylalanine hydroxylase : structure-function analysis of selected mutant forms

Tese de doutoramento em Bioquímica (Biologia Molecular) apresentada à Fac. de Ciências e Tecnologia de Coimbr

Diatoms for omics applications in water monitoring

Diatoms are driving forces in marine and freshwater ecosystems by sustaining aquatic food webs and by having leading roles in the fixation of carbon and silica. The morphological diversity of the silicified cell walls from different diatom species has for long been used for the biotic characterization of environmental samples. This has been accomplished by the development of microscopic-based diatom biological indices that provided information on the diversity and abundance of the different species. Recent developments in omics technologies, coupled with bioinformatic tools for complex omics data analysis is opening the doors for the use of diatoms as target organisms in the assessment of water quality using molecular studies. Specific universal genes of interest are being used to characterize the diatom populations in environmental samples. In addition, fully sequenced diatom species are currently being applied for toxicological studies aiming at the unveiling of the mode of action of pollutants. It is envisioned that molecular studies on diatoms will become major tools in the ecological assessment of environmental samples, matching their key roles in the ecosystem.JRC.H.5-Rural, water and ecosystem resource

Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments

Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean Sea (Genoa, Italy), due to intense industrial and harbor activities. The gene expression data for exposure to the sediment-derived PAH mixture was compared with gene expression data for in vitro exposure to specific polycyclic aromatic hydrocarbons. The data shows that genes involved in stress response, silica uptake, and metabolism were regulated both upon exposure to the sediment-derived PAH mixture and to the single component. Complementary monitoring of silica in the diatom cultures provide further evidence of a reduced cellular uptake of silica as an end-point for benzo[a]pyrene exposure that could be linked with the reduced gene and protein expression of the silicon transporter protein. However some genes showed differences in regulation indicating that mixtures of structurally related chemical compounds can elicit a slightly different gene expression response compared to that of a single component. The paper provides indications on the specific pathways affected by PAH exposure and shows that selected genes (silicon transporter, and silaffin 3) involved in silica uptake and metabolism could be suitable molecular biomarkers of exposure to PAHs.JRC.H.1-Water Resource

Effects of Silver nanoparticles in diatom Thalassiosira pseudonana and cyanobacterium Synechococcus sp.

The aim of the present study was to investigate the effect of silver nanoparticles (AgNP) of different sizes towards two primary producer aquatic species. Thalassiosira pseudonana and Synechococcus sp. have been selected as representative models for the lower trophic organisms in marine and freshwater habitats, respectively. Time-dependent cellular growth was measured under exposure to both AgNP and silver nitrate (AgNO3). In addition, AgNP behavior in freshwater and marine waters has been followed by CPS disk centrifuge, in the time-frame of AgNP exposure studies, and the kinetic release of silver from AgNP of different sizes was measured by inductively coupled plasma mass spectrometry (ICP-MS). The combination and interpretation of all these data suggest that a shared effect of AgNP and free silver ions (Ag+ ) was responsible for the toxicity in both organisms, while the cyanobacteria were the most sensitive specie to both AgNP and Ag+. Furthermore the relative contribution of Ag+ and AgNP to the measured toxicity was dependent on the stability of the preparation.JRC.H.1-Water Resource

Pedagogía social : revista interuniversitaria

Resumen basado en el de la publicaciónTítulo, resumen y palabras clave en portugués, inglés y españolMonográfico con el título: “Educación para una cultura de la sostenibilidad : eco-ciudadanía, políticas públicas y participación social”Título del monográfico en inglés: “Education for a culture of sustainability : eco-citizenship, public policies and social participation”Partiendo de la articulación entre la pedagogía escolar y la pedagogía social, se identifican formas efectivas de garantizar el derecho a la educación de los jóvenes vulnerables y marginados que abandonaron la escuela temprano. La investigación fue parte de un proyecto europeo que investigó cómo las respuestas de los jóvenes al conflicto pueden ofrecer oportunidades para una participación social positiva. Se exploró el abandono y la reincorporación escolar desde el punto de vista de un grupo de 20 jóvenes portugueses que abandonaron la escuela y luego la reanudaron a través de proyectos educativos de segunda oportunidad. Con un enfoque cualitativo, utilizando entrevistas individuales, observación participante y grupos focales, el estudio buscó una lectura integral del abandono y la reincorporación escolar, abordando la diversidad de motivaciones, experiencias, factores y consecuencias asociadas con ellos y el rol de las políticas educativas y factores escolares en estos fenómenos. Los resultados han revelado que, para muchos jóvenes social y económicamente vulnerables, las escuelas convencionales son lugares de fracaso individual y de conflicto interpersonal donde no se sienten bienvenidos y donde ya no esperan resultados positivos. Esto favorece un distanciamiento progresivo de la educación que refuerza su marginación social. Por otro lado, los resultados revelan que, al participar en proyectos educativos de segunda oportunidad, los jóvenes muestran un mayor compromiso con la educación e identifican cambios personales positivos de desarrollo personal y de habilidades, ajuste de comportamiento y establecimiento de objetivos de vida. El enfoque socio pedagógico holístico e individualizado de la educación de segunda oportunidad ha demostrado ser particularmente apropiado para satisfacer las necesidades de estos jóvenes. Las estrategias educativas basadas en la comunidad, los entornos de aprendizaje prácticos y participativos y la inversión emocional de los maestros y el personal han demostrado ser los recursos socioeducativos más eficaces para volver a involucrar a los jóvenes vulnerables en la educación.ES

Development and application of the adverse outcome pathway framework for understanding and predicting chronic toxicity: II. A focus on growth impairment in fish

Adverse outcome pathways (AOPs) organize the knowledge on the progression of toxicity through levels of biological organization. By elucidating the linkages between toxicity events on different levels, the AOPs lay the foundation for mechanism-based alternative testing approaches to hazard assessment. We have previously suggested that development of chronic toxicity AOPs can improve understanding of chronic toxicity and facilitate development of alternative tests. Here, we illustrate this process by focusing on fish growth, which is an apical adverse outcome commonly assessed in chronic toxicity tests, for which the alternatives are actively sought-for. Based on four criteria, namely importance of a particular process for growth-related outcomes, pathway conservation across species, frequency of occurrence of a certain disruption and environmental relevance of chemical-induced effects, we selected to focus on reduction in food intake to initiate middle-out AOP development. To explore the link between reduction in food intake and growth impairment, as well as the mechanisms that cause reduction in food intake, we developed three AOP case studies for pyrethroids, selective serotonin reuptake inhibitors (SSRIs) and cadmium. Our analysis demonstrated that the reduction in food intake is strongly linked to growth impairment in case of pyrethroids and SSRIs, but not cadmium. For pyrethroids, impairment of locomotion is strongly linked to the effects on food intake and growth, but in case of SSRIs, their direct effects on appetite may play a role more important than their impacts on locomotion. For cadmium, the main cause of growth impairment is reallocation of energy resources due to increased maintenance costs. We further discuss which alternative tests can be developed and used to inform on the key events we identified to be predictive of effects on growth. In conclusion, our work demonstrated how the AOP concept can be used in practice to critically assess the knowledge available for specific chronic toxicity cases in order to identify existing knowledge gaps and potential alternative tests.JRC.H.1-Water Resource