Project description:This SuperSeries is composed of the following subset Series: GSE22171: Pacific salmon gill samples: fate tracking in river, sampled in ocean GSE22177: Pacific salmon gill samples: fate tracking in river GSE22347: Pacific salmon gill samples: fate tracking at spawning grounds Refer to individual Series
Project description:The polysaccharide β-mannan, which is common in terrestrial plants but unknown in microalgae, was recently detected during diatom blooms. We identified a β-mannan polysaccharide utilization locus (PUL) in the genome of the marine Flavobacterium Muricauda sp. MAR_2010_75 which resembles PULs in bacteria from diverse ecosystems. Proteomics showed the β-mannan induced translation of 22 proteins encoded within the PUL.
Project description:DNA oligonucleotide microarrays were designed with 307 probes for 96 internal transcribed spacer (ITS1, located between 18S and 26S rRNA genes) sequences of known species and strains from the genus Pseudo-nitzschia (Bacillariophyceae). In addition, microarrays also carried 1893 probes targeting ITS1 aequences of marine Crenarchaeota and Alphaproteobacteria of SAR11 clade. In order to assign microarray profiles to Pseudo-nitzschia ribotypes and species and to 'train' the data analysis system, we grew cultures of Pseudo-nitzschia in the laboratory with identities confirmed through rDNA sequence analysis. In total, 9 cultures and 35 environmental water samples were hybridized to microarrays, in some cases, in duplicate or triplicate. Analysis of microarray data allowed us to identify and map Pseudo-nitzschia spp. in the coastal waters along Washington and Oregon coast of the Eastern Pacific Ocean, and to observe seasonal changes in diatom community composition. Total DNA was isolated from 9 Pseudo-nitzschia laboratory cultures and 35 environmental water samples collected during 7 field campaigns in 2007-2009. The environmental samples were collected at distances of 5 to 55 km from the coast, along the following transects in the Pacific Ocean covering over 300 km of the coastline: La Push (LP), Grays Harbor (GH), Columbia River (CR), and Newport Hydroline (NH). The DNA samples were subjected to PCR amplification with the primers specific for ITS1 sequences. The resultant biotin-labeled target samples were analyzed using microarray hybridization with the CombiMatrix ElectraSense 4X2K format. Out of 44 analyzed samples, 40, 2, and 2 were used for single, duplicate and triplicate hybridizations, respectively.
Project description:Previous studies have demonstrated that the iron content in marine heterotrophic bacteria is comparatively higher than that of phytoplankton. Therefore, they have been indicated to play a major role in the biogeochemical cycling of iron. In this study, we aimed to investigate the potential of viral lysis as a source of iron for marine heterotrophic bacteria. Viral lysates were derived from the marine heterotrophic bacterium, Vibrio natriegens PWH3a (A.K.A Vibrio alginolyticus). The bioavailability of Fe in the lysates was determined using a model heterotrophic bacterium, namely, Dokdonia sp. strain Dokd-P16, isolated from Fe-limited waters along Line P transect in the Northeastern Pacific Ocean. The bacteria were grown under Fe-deplete or Fe-replete conditions before being exposed to the viral lysate. Differential gene expression following exposure to the viral lysate was analyzed via RNA sequencing to identify differentially expressed genes under iron-replete and iron-deplete conditions. This study would provide novel insights into the role of viral lysis in heterotrophic bacteria in supplying bioavailable iron to other marine microorganisms under iron-limiting and non-limiting conditions. First, the marine heterotrophic bacterium genome, Dokdonia sp. strain Dokd-P16, was sequenced to provide a genomic context for the expression studies. Subsequently, the relative gene expression in Dokdonia sp. strain Dokd-P16 grown under Fe limiting and non-limiting conditions were analyzed. This transcriptomic approach would be utilized to elucidate genes regulated by Fe availability in Dokdonia sp. strain Dokd-P16, which indicate its Fe-related response viral lysate exposure. Taken together, in this study, the transcriptomic responses of Fe-limited and non-limited marine heterotrophic bacteria were analyzed, which provided novel insights into the biological availability of Fe from the viral lysates.
Project description:Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation Thalassiosira pseudonana and 4 open-ocean diatoms were subjected to iron limitation or short-term oxidative stress (hydrogen peroxide). mRNA profiles of T. pseudonana (CCMP1335), Thalassiosira oceanica (CCMP1005), Amphora coffeaeformis (CCMP1405), Chaetoceros sp. (CCMP199), and Cylindrotheca closterium (CCMP340).
Project description:Isolation and characterization of two recently isolated Novosphingobium oxfordensis sp. nov. and Novosphingobium mississippiensis sp. nov. strains from soil, with LCMS and genome-based investigation of their glycosphingolipid productions
