Impact of a heterotroph, Alteromonas MIT1002, on the transcriptome of Prochlorococcus NATL2A
Ontology highlight
ABSTRACT:
ORGANISM(S): Alteromonas macleodii Prochlorococcus marinus str. NATL2A
PROVIDER: GSE73511 | GEO | 2016/06/10
SECONDARY ACCESSION(S): PRJNA297192
REPOSITORIES: GEO
Similar Datasets
Project description:We examine how the transcriptome of Prochlorococcus strain NATL2A changes in the presence of a naturally co-occurring heterotroph, Alteromonas macleodii MIT1002. Significant changes in the Prochlorococcus transcriptome were evident within six hours of co-culture, with groups of transcripts changing in different temporal waves. Many transcriptional changes persisted throughout the 48-hour experiment, indicating that the presence of the heterotroph affected a stable shift in Prochlorococcus physiology. These initial transcriptome changes largely correspond to reduced stress conditions within Prochlorococcus, as inferred from decreases in relative abundance for transcripts encoding DNA repair enzymes and many members of the âhigh-light inducibleâ family of stress response proteins. Notable changes were also seen in transcripts encoding components of the photosynthetic apparatus (particularly an increase in PSI subunits and chlorophyll synthesis enzymes), ribosomal proteins and biosynthetic enzymes. Changes in secretion-related proteins and transporters also highlight the potential for metabolic exchange between the two strains. At each of 7 timepoints, samples from 3 biological replicate co-cultures are compared to 3 biological replicate axenic Prochlorococcus cultures that serve as a control.
2016-06-10 | E-GEOD-73511 | biostudies-arrayexpress
Project description:We examine how the transcriptome of Prochlorococcus strain NATL2A changes in response to extended light deprivation, both when grown alone and in the presence of a naturally co-occurring heterotroph, Alteromonas macleodii MIT1002.
2018-05-01 | GSE93197 | GEO
Project description:Prochlorococcus is found throughout the euphotic zone in the oligotrophic open ocean. Deep mixing and sinking in aggregates or while attached to particles can, however, transport cells below this sunlit zone, depriving them of light for extended periods of time and influencing their circulation via ocean currents. Viability of these cells over extended periods of darkness could shape the ecology and evolution of the Prochlorococcus collective. We have shown that when co-cultured with a heterotrophic microbe and subjected to repeated periods of extended darkness, Prochlorococcus cells develop a heritable dark-tolerant phenotype – through an apparent epigenetic mechanism – such that they survive longer periods of darkness. Here we examine this adaptation at the level of physiology and metabolism in co-cultures of dark-tolerant and parent strains of Prochlorococcus, each grown with the heterotroph Alteromonas under diel light:dark conditions. The relative abundance of Alteromonas is higher in dark-tolerant than parental co-cultures, while dark tolerant Prochlorococcus cells are also larger, contain less chlorophyll, and are less synchronized to the light:dark cycle. Meta-transcriptome analysis of the cultures further suggests that dark-tolerant co-cultures undergo a coupled shift in which Prochlorococcus uses more organic carbon and less photosynthesis, and Alteromonas uses more organic acids and fewer sugars. Collectively, the data suggest that dark adaptation involves a loosening of the coupling between Prochlorococcus metabolism and the light:dark cycle and a strengthening of the coupling between the carbon metabolism of Prochlorococcus and Alteromonas.
2024-04-23 | GSE264347 | GEO
Project description:Carbon fixation plays a central role in determining cellular redox poise, increasingly understood to be a key parameter in cyanobacterial physiology. In the cyanobacterium Prochlorococcus--—the most abundant phototroph in the oligotrophic oceans--—the carbon-concentrating mechanism (CCM) is reduced to the bare essentials. Given the ability of Prochlorococcus populations to grow under a wide range of oxygen concentrations in the ocean, we wondered how carbon and oxygen physiology intersect in this minimal phototroph. We monitored genome-wide transcription in cells shocked with acute limitation of CO2, O2, or both. O2 limitation produced much smaller transcriptional changes than the broad suppression seen under CO2 limitation and CO2/O2 co-limitation. Strikingly, the transcriptional responses evoked by both CO2 limitation conditions were initially similar to that previously seen in high light stress, but at later timepoints we observed O2-dependent recovery of photosynthesis-related transcripts. These results suggest that oxygen plays a protective role in Prochlorococcus when carbon fixation is not a sufficient sink for light energy.
2015-04-15 | GSE65684 | GEO
Project description:RNA decay was measured in Prochlorococcus after inhibition of transcription by rifampicin using customized Affymetrix gene expression arrays. RNA turnover plays an important role in the gene regulation of microorganisms and influences their speed of acclimation to environmental changes. We investigated whole-genome RNA stability of Prochlorococcus, a relatively slow-growing marine cyanobacterium doubling approximately once a day, which is extremely abundant in the oceans. Using a combination of microarrays, quantitative RT-PCR and a new algorithm for determining RNA decay rates, we found a median half-life of 2.4 min and a median decay rate of 2.6 min for expressed genes â two-fold faster than that reported for any organism. The shortest transcript half-life (33 seconds) was for a gene of unknown function, while some of the longest (ca. 18 min) were for highly expressed genes. Genes organized in operons displayed intriguing mRNA decay patterns, such as increased stability, and delayed onset of decay with greater distance from the transcriptional start site. The same phenomenon was observed on a single probe resolution for genes greater than 2 kb. We hypothesize that the fast turnover relative to generation time in Prochlorococcus may enable a swift response to environmental changes through rapid recycling of nucleotides, which could be advantageous in nutrient poor oceans. Our growing understanding of RNA half-lives will inform on the modelling of cell processes and help interpret the growing bank of metatranscriptomic studies of wild populations of Prochlorococcus. The surprisingly complex decay patterns of large transcripts reported here, and the method developed to describe them, will open new avenues for the investigation and understanding of RNA decay for all organisms. Prochlorococcus cells were treated with rifampicin, which prevents initiation of new transcripts. Cells were harvested at 0 min (before rifampicin addition), 2.5 min, 5 min, 10 min, 20 min, 40 min and 60 min after rifampicin addition.
2010-05-16 | E-GEOD-17075 | biostudies-arrayexpress
Project description:We report the full transcriptome of T4-like cyanophage P-HM2 infecting Prochlorococcus in light and dark
2016-03-18 | GSE79359 | GEO
Project description:Carbon fixation plays a central role in determining cellular redox poise, increasingly understood to be a key parameter in cyanobacterial physiology. In the cyanobacterium Prochlorococcus--—the most abundant phototroph in the oligotrophic oceans--—the carbon-concentrating mechanism (CCM) is reduced to the bare essentials. Given the ability of Prochlorococcus populations to grow under a wide range of oxygen concentrations in the ocean, we wondered how carbon and oxygen physiology intersect in this minimal phototroph. We monitored genome-wide transcription in cells shocked with acute limitation of CO2, O2, or both. O2 limitation produced much smaller transcriptional changes than the broad suppression seen under CO2 limitation and CO2/O2 co-limitation. Strikingly, the transcriptional responses evoked by both CO2 limitation conditions were initially similar to that previously seen in high light stress, but at later timepoints we observed O2-dependent recovery of photosynthesis-related transcripts. These results suggest that oxygen plays a protective role in Prochlorococcus when carbon fixation is not a sufficient sink for light energy. Two biological replicates of timecourses under four conditions: medium bubbled with air (control) or three experimental gases (low CO2; low O2; or low CO2 and low O2)
2015-04-15 | E-GEOD-65684 | biostudies-arrayexpress
Project description:Prochlorococcus is an obligate marine microorganism which are dominant autotroph in tropical and subtropical central oceans. However, what is the low salinity boundary and how Prochlorococcus would response to low salinity exposure is still unknown. In this study, we first tested the growing salinity range of two Prochlorococcus strains, NATL1A and MED4, and then compared the global transcriptome of their low salinity acclimated cells and cells growing in normal seawater salinity. We found that MED4 could be acclimated in the lowest salinity of 25% and NATL1A could be acclimated in the lowest salinity of 28%. Measurement of the effective quantum yield of PSII photochemistry (Fv/Fm) indicated that both strains were stressed when growing in salinity lower than 34%. The transcriptomic response of NATL1A and MED4 were approximately different, with much more genes having changed transcript abundance in NATL1A than in MED4. To cope with low salinity, NATL1A downregulated the transcript of most genes involved in translation, ribosomal structure and biogenesis, while MED4 upregulated those genes. Moreover, low salinity acclimated NATL1A cells suppressed ATP-producing genes and induced the expression of photosynthesis related genes, while low salinity acclimated MED4 upregulated ATP-producing genes and downregulated photosynthesis related genes. These results indicate that the response to low salinity stress of different Prochlorococcus strains could be distinct. The study provided the first glimpse into the growing salinity range of Prochlorococcus cells and their global gene expression changes due to low salinity stress.
2022-02-02 | GSE195946 | GEO
Project description:Extracellular vesicles are small (50-200 nm diameter) membrane-bound structures released by cells from all domains of life. Vesicles have been implicated in numerous microbial processes, including gene transfer, signaling, pathogenesis, and defense. While vesicles are abundant in the oceans, little is known about their contents or whether they interact with cells in this dilute environment. Here we show that extracellular vesicles contain a remarkable diversity of organic carbon compounds and likely mediate a complex network of export, transport and exchange within marine microbial communities. We report that vesicles from selected strains of Prochlorococcus, the most abundant cyanobacterium in the sea, and other bacteria can interact with cells of various marine microbes, including the numerically abundant heterotroph Pelagibacter. Through a combination of lipidomic, metabolomic and proteomic analyses, we show that two strains of Prochlorococcus export an enormous array of organic and inorganic compounds – including active, biogeochemically relevant enzymes – within vesicles. Vesicles from both strains contained some materials in common as well as numerous strain-specific differences, reflecting an even greater degree of functional complexity within natural vesicle populations. These data suggest additional roles for vesicles in carrying out extracellular biogeochemical reactions, mitigating toxicity from reactive oxygen species, and mediating energy and nutrient transfers in the oceans.
2021-11-23 | PXD013602 | Pride
Project description:RNA decay was measured in Prochlorococcus after inhibition of transcription by rifampicin using customized Affymetrix gene expression arrays. RNA turnover plays an important role in the gene regulation of microorganisms and influences their speed of acclimation to environmental changes. We investigated whole-genome RNA stability of Prochlorococcus, a relatively slow-growing marine cyanobacterium doubling approximately once a day, which is extremely abundant in the oceans. Using a combination of microarrays, quantitative RT-PCR and a new algorithm for determining RNA decay rates, we found a median half-life of 2.4 min and a median decay rate of 2.6 min for expressed genes – two-fold faster than that reported for any organism. The shortest transcript half-life (33 seconds) was for a gene of unknown function, while some of the longest (ca. 18 min) were for highly expressed genes. Genes organized in operons displayed intriguing mRNA decay patterns, such as increased stability, and delayed onset of decay with greater distance from the transcriptional start site. The same phenomenon was observed on a single probe resolution for genes greater than 2 kb. We hypothesize that the fast turnover relative to generation time in Prochlorococcus may enable a swift response to environmental changes through rapid recycling of nucleotides, which could be advantageous in nutrient poor oceans. Our growing understanding of RNA half-lives will inform on the modelling of cell processes and help interpret the growing bank of metatranscriptomic studies of wild populations of Prochlorococcus. The surprisingly complex decay patterns of large transcripts reported here, and the method developed to describe them, will open new avenues for the investigation and understanding of RNA decay for all organisms.
2009-12-31 | GSE17075 | GEO