Project description:Marine cyanobacteria are thought to be the most sensitive of the phytoplankton groups to copper toxicity, yet little is known of the transcriptional response of marine Synechococcus to copper shock. Global transcriptional response to two levels of copper shock was assayed in both a coastal and an open ocean strain of marine Synechococcus using whole genome expression microarrays. Both strains showed an osmoregulatory-like response, perhaps as a result of increasing membrane permeability. This could have implications for marine carbon cycling if copper shock leads to dissolved organic carbon leakage in Synechococcus. The two strains additionally showed a reduction in photosynthetic gene transcripts. Contrastingly, the open ocean strain showed a typical stress response whereas the coastal strain exhibited a more specific oxidative or heavy metal type response. In addition, the coastal strain activated more regulatory elements and transporters, many of which are not conserved in other marine Synechococcus strains and may have been acquired by horizontal gene transfer. Thus, tolerance to copper shock in some marine Synechococcus may in part be a result of an increased ability to sense and respond in a more specialized manner.
Project description:In this study we characterize microbial community features on the surface of Indian Ocean. 11 samples were collected from Indian Ocean and subjected for quantitative metaproteomics analysis for taxonomic and functional analysis. Our results suggested that metabolic tuning at metaproteomics levels enabled microbial community to sustain stable when subjected to environmental perturbations in the oligotrophic ocean.
Project description:Marine cyanobacteria are thought to be the most sensitive of the phytoplankton groups to copper toxicity, yet little is known of the transcriptional response of marine Synechococcus to copper shock. Global transcriptional response to two levels of copper shock was assayed in both a coastal and an open ocean strain of marine Synechococcus using whole genome expression microarrays. Both strains showed an osmoregulatory-like response, perhaps as a result of increasing membrane permeability. This could have implications for marine carbon cycling if copper shock leads to dissolved organic carbon leakage in Synechococcus. The two strains additionally showed a reduction in photosynthetic gene transcripts. Contrastingly, the open ocean strain showed a typical stress response whereas the coastal strain exhibited a more specific oxidative or heavy metal type response. In addition, the coastal strain activated more regulatory elements and transporters, many of which are not conserved in other marine Synechococcus strains and may have been acquired by horizontal gene transfer. Thus, tolerance to copper shock in some marine Synechococcus may in part be a result of an increased ability to sense and respond in a more specialized manner. In this series four conditions have been analyzed. These are moderate copper shock for Synechococcus sp. WH8102 and CC9311 (pCu 11.1 and pCu 10.1, respectively), and high copper shock for WH8102 and CC9311 (pCu 10.1 and pCu 9.1, respectively). For each slide, an experimental RNA sample was labeled with Cy3 or Cy5 and was hybridized with a reference RNA from a non-copper-shocked sample labeled with the other Cy dye. There are six or eight slides per condition, each with two biological replicates. There are three or four technical replicates for each biological replicate including at least one flip-dye comparison. Each slide contains six replicate spots per gene.