Project description:We used a cDNA microarray previously defined for the marine sentinel organism Mytilus galloprovincialis (MytArray1.0) to evaluate the effects of nanomolar doses of combined metal salts (50, 100 and 200 nM mixtures of Cd, Cu and Hg) after 48 hours of mussel exposure. Pointing to the mussel gills, first target of toxic water contaminants and actively proliferating tissue, we found significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel pulp by atomic absorption spectrometry. Following gill RNA purification and DNA microarray analysis, individual gene expression profiles revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses with roughly similar amounts of up- and down-regulated signals. The functional annotation of transcripts with consistent expression trends and significantly altered at least in one dose point disclosed the complexity of the induced cell response.
Project description:We used a cDNA microarray previously defined for the marine sentinel organism Mytilus galloprovincialis (MytArray1.0) to evaluate the effects of nanomolar doses of combined metal salts (50, 100 and 200 nM mixtures of Cd, Cu and Hg) after 48 hours of mussel exposure. Pointing to the mussel gills, first target of toxic water contaminants and actively proliferating tissue, we found significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel pulp by atomic absorption spectrometry. Following gill RNA purification and DNA microarray analysis, individual gene expression profiles revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses with roughly similar amounts of up- and down-regulated signals. The functional annotation of transcripts with consistent expression trends and significantly altered at least in one dose point disclosed the complexity of the induced cell response. Three-condition experiment (50, 100 and 200 nM doses), individual treated mussel vs. pooled control mussels (N=5), 3 biological replicates with dye-swap competitive hybridization (array A and B, 2 technical replicates/array).
Project description:To analyze the different pattern of expression among tissues in D. polymorpha it was used acustom microarray designed in our laboratory using 4057 publicly availabe DNA sequences from Dreissena and other realted genera. Transcriptome profiles were analyszed using gills, digestive gland, gonad and half a body of adult zebra mussel and larvae 24 h pf. The samples analyzed in the microarray were not treated in order to detect the normal pattern of expression in each tissue. A total of 221 transcripts changed significantly their mRNA levels in the different tissues (ANOVA p<0.01, fc ±1.5). The results showed a clear separation on transcriptome profiles between samples with the main changes in gills, larvae and half a body.
Project description:To analyze the different pattern of expression among tissues in D. polymorpha it was used acustom microarray designed in our laboratory using 4057 publicly availabe DNA sequences from Dreissena and other realted genera. Transcriptome profiles were analyszed using gills, digestive gland, gonad and half a body of adult zebra mussel and larvae 24 h pf. The samples analyzed in the microarray were not treated in order to detect the normal pattern of expression in each tissue. A total of 221 transcripts changed significantly their mRNA levels in the different tissues (ANOVA p<0.01, fc ±1.5). The results showed a clear separation on transcriptome profiles between samples with the main changes in gills, larvae and half a body. Non treated animals were use to study different patterns of gene expression in different tissues using gills, digestive gland, gonad from both sexes, and half a body as well as larvae. It was used 2 replicate for each tissue.
Project description:The zebra mussel is present in Spain since early 2000,s, when it was discovered in the lower part of the Ebro river. To study the gene expression pattern of different populations of zebra mussel a long the Ebro River we use a custom microarray developed in our laboratory, using 4057 publicly available DNA sequences from Dreissena polymorpha and other related genera. Also it was used an external sampling site located in Sitjar Dam, about 200km form the Ebro river. Transcriptome profiles were analysed using the gills of individuals collected in the same period (20-23 March) to diminish seasonal effects. A total of 755 transcripts changed significantly their mRNA levels among the sites of the study (ANOVA p<0.01, fc M-BM-11.5). Genes encoding for xenobiotic, energetic and calcium metabolism and cell proliferation were those showing the highest differences among populations. Geographical origin appeared as the major driver of the differences among the studied populations, as the transcriptomic profiles from four populations collected within a radius of few km around the Flix factory clustered together and separated from those from other distant populations both upstream the Ebro River or in the Sitjar dam. Differences on gene expression pattern were measure in gills of Dreissena polymorpha in different populations in five populations along the Ebro river and one population in Sitjar dam. The collection of samples were done during Srping (March). For the microarray it was used 2 replicates of each sites of the study.
Project description:Bathymodiolus azoricus is a deep-sea mussel found in the hydrothermal vent fields of the Mid-Atlantic Ridge. It lives in symbiosis with sulfur- and methane-oxidizing γ-proteobacteria within its gills. In our study, we aimed to understand the metabolic and physiological interconnections between the symbiotic partners. For this purpose, symbionts and host were physically separated using density gradient centrifugation. This procedure yielded a symbiont-enriched gradient pellet fraction and a supernatant fraction enriched in host components. The cytosolic and membrane-associated proteome of both these fractions along with whole gill and foot tissue of the mussel were then investigated through 1D-PAGE LC-MS/MS. Proteins were quantified based on their spectral counts using the NSAF method. For efficient identification, sequences from evolutionarily related endosymbiotic and free-living bacteria and from bivalve host relatives were compiled into a comprehensive protein database. A total of 3178 host and symbiont proteins were identified from all samples.
Project description:Transcriptional profiling of the digestive gland tissue of female mussel Mytilus galloprovincialis exposed to copper along with a temperature gradient Background: Global warming is a major factor that may affect biological organization, especially in marine ecosystems and in coastal areas that are particularly subject to anthropogenic pollution. We evaluated the effects of simultaneous changes in temperature and copper concentrations on lysosomal membrane stability of the blue mussel Mytilus galloprovincialis (Lam.). Temperature and copper exerted additive effects on lysosomal membrane stability, exacerbating the toxic effects of metal cations present in non-physiological concentrations. Mussel lysosomal membrane stability was positively related toscope for growth, indicating possible effects of increasing temperature on mussel populations in metal-polluted areas. To clarify the molecular response to environmental stressors, we used a cDNA microarray with 1,700 sequences to measure the relative transcript abundances in the gills of mussels exposed to copper (40µg/L) and a temperature gradient (16°C, 20°C, and 24°C). In animals exposed only to heat stress, hierarchical clustering of the microarray data revealed three main clusters, which were largely dominated by down-regulation of translation-related differentially expressed genes, drastic up-regulation of folding protein-related genes, and genes involved in chitin metabolism. The response of mussels exposed to copper at 24° C was characterized by an opposite pattern of the genes involved in translation, most of which were up-regulated, as well asthe down-regulation of genes encoding heat shock proteins and microtubule-based movement proteins. Our data provide novel information on the transcriptomic modulations in mussels facing temperature increases and high copper concentrations; these data highlight the risk of marine life exposed to toxic chemicals in the presence of temperature increases due to climate change.