Project description:Mytilus galloprovincialis (Lmk, 1819) is economically relevant bivalve specie. In Adriatic Sea, periodical temperatures increases define optimal growth conditions for Dinoflagellate spp which can reach high concentrations also in filter-feeding mussels, thus causing potential human health problems. The most commonly used methods for the detection of Diarrhoeic Shellfish Poisoning biotoxins have either a low sensitivity or are too expensive to be used for routine tests. Genomic tools, such as microarray platforms, provide a reliable and alternative solution to overcome these problems. In this study we used a mussel cDNA microarray for studying gene expression changes in mussels exposed to Okadaic acid. Mussels collected in the Gulf of Trieste, located in Northern Adriatic Sea, were fed with Okadaic acid-spiked invertebrates for five weeks. In a time course experiment we were able to describe an early acute response just from the first 4th day time point. Among the differentially expressed genes we found a general up-regulation of stress proteins and proteins involved in cellular synthesis. Overall, we identified 34 transcripts candidate as useful markers to monitor OA-induced stress in mussels. This study contributes to the characterization of many potential genetic markers that could be used in future environmental monitoring, and could lead to explore new mechanisms of stress tolerance in marine mollusc species. Keywords: Time course, stress response
Project description:Mytilus galloprovincialis (Lmk, 1819) is economically relevant bivalve specie. In Adriatic Sea, periodical temperatures increases define optimal growth conditions for Dinoflagellate spp which can reach high concentrations also in filter-feeding mussels, thus causing potential human health problems. The most commonly used methods for the detection of Diarrhoeic Shellfish Poisoning biotoxins have either a low sensitivity or are too expensive to be used for routine tests. Genomic tools, such as microarray platforms, provide a reliable and alternative solution to overcome these problems. In this study we used a mussel cDNA microarray for studying gene expression changes in mussels exposed to Okadaic acid. Mussels collected in the Gulf of Trieste, located in Northern Adriatic Sea, were fed with Okadaic acid-spiked invertebrates for five weeks. In a time course experiment we were able to describe an early acute response just from the first 4th day time point. Among the differentially expressed genes we found a general up-regulation of stress proteins and proteins involved in cellular synthesis. Overall, we identified 34 transcripts candidate as useful markers to monitor OA-induced stress in mussels. This study contributes to the characterization of many potential genetic markers that could be used in future environmental monitoring, and could lead to explore new mechanisms of stress tolerance in marine mollusc species. Keywords: Time course, stress response Loop Design experiment including 5 time points (T0 = control samples, T1 = 3 days post treatment, T2 = 1 week post treatment, T4 = 3 weeks post treatment, T6 = 5 weeks post treatment). 3 biological replicates were done for a total number of 15 samples
Project description:Gas hydrates, also known as clathrates, are cages of ice-like water crystals encasing gas molecules such as methane (CH4). Despite the global importance of gas hydrates, their microbiomes remain mysterious. Microbial cells are physically associated with hydrates, and the taxonomy of these hydrate-associated microbiomes is distinct from non-hydrate-bearing sites. Global 16S rRNA gene surveys show that members of sub-clade JS-1 of the uncultivated bacterial candidate phylum Atribacteria are the dominant taxa in gas hydrates. The Atribacteria phylogeny is highly diverse, suggesting the potential for wide functional variation and niche specialization. Here, we examined the distribution, phylogeny, and metabolic potential of uncultivated Atribacteria in cold, salty, and high-pressure sediments beneath Hydrate Ridge, off the coast of Oregon, USA, using a combination of 16S rRNA gene amplicon, metagenomic, and metaproteomic analysis. Methods were developed to extract bacterial cellular protein from these sediments, as outlined below. Sample Description Three sediments samples were collected from beneath Hydrate Ridge, off the coast of Oregon, USA. Sediments were cored at ODP site 1244 (44°35.1784´N; 125°7.1902´W; 895 m water depth) on the eastern flank of Hydrate Ridge ~3 km northeast of the southern summit on ODP Leg 204 in 2002 and stored at -80°C at the IODP Gulf Coast Repository. E10H5 sediment is from 68.5 meters below sediment surface interface C1H2 sediment is from 2 meters below sediment surface interface. C3H4 sediment is from 21 meters below sediment surface interface.