Project description:description Blastocystis sp. is a highly prevalent anaerobic eukaryotic parasite of humans and animals. The genome of several representatives has been sequenced revealing specific traits such as an intriguing 3’-end processing of primary transcripts. We have acquired a first high-throughput proteomics dataset on the difficult to cultivate ST4 isolate WR1 and detected 2,761 proteins. We evidenced for the first time by proteogenomics a functional termination codon derived from transcript polyadenylation for seven different key cellular components.
Project description:The unicellular cyanobacterium Synechocystis sp. PCC 6803 is a model system for studying biochemistry, genetics and molecular biology of photobiological processes. Despite its importance in basic and applied research, the genome-wide picture of transcriptional regulation in this bacterium is limited. Characteristic transcriptional responses to changes in the growth environment are expected to provide a scaffold for describing the Synechocystis transcriptional regulatory network as well as efficient means for functional annotation of genes in the genome. We designed, validated and used Synechocystis genome-wide oligonucleotide (70-mer) microarray (representing 96.7% of all chromosomal ORFs) to study transcriptional activity of the cyanobacterial genome in response to S deprivation. The microarray data were verified by quantitative RT-PCR. We made five main observations: 1) Transcriptional changes upon sulfate withdrawal were relatively moderate, but significant and consistent with growth kinetics; 2) S acquisition genes encoding for a high-affinity sulfate transporter were significantly induced, while decreased transcription of genes for phycobilisome, photosystems I and II, cytochrome b6/f, and ATP synthase indicated reduced light-harvesting and photosynthetic activity; 3) S deprivation elicited transcriptional responses associated with general growth arrest and stress; 4) A large number of genes regulated by S availability encode hypothetical proteins or proteins of unknown function; 5) Hydrogenase structural and maturation accessory genes were not identified as differentially expressed, even though increased hydrogen evolution was observed. The expression profiles recorded by using this oligonucleotide-based microarray platform revealed that during transition from the condition of plentiful sulfur to no sulfur, Synechocystis undergoes coordinated transcriptional changes, including genes whose products are involved in sensing nutrient limitations and tuning bacterial metabolism. The transcriptional profile of the nutrient limitation was dominated by decrease in abundances of many transcripts. However, these changes were unlikely due to the across-the-board, non-specific shut down of transcription in a condition of growth arrest. Down-regulation of transcripts encoding proteins whose function depends on a cellular sulfur status indicated that the observed repression has a specific regulatory component. The repression of certain sulfur-related genes was paralleled by activation of genes involved in internal and external S scavenging. Keywords: stress response, time course
Project description:The unicellular cyanobacterium Synechocystis sp. PCC 6803 is a model system for studying biochemistry, genetics and molecular biology of photobiological processes. Despite its importance in basic and applied research, the genome-wide picture of transcriptional regulation in this bacterium is limited. Characteristic transcriptional responses to changes in the growth environment are expected to provide a scaffold for describing the Synechocystis transcriptional regulatory network as well as efficient means for functional annotation of genes in the genome. We designed, validated and used Synechocystis genome-wide oligonucleotide (70-mer) microarray (representing 96.7% of all chromosomal ORFs) to study transcriptional activity of the cyanobacterial genome in response to S deprivation. The microarray data were verified by quantitative RT-PCR. We made five main observations: 1) Transcriptional changes upon sulfate withdrawal were relatively moderate, but significant and consistent with growth kinetics; 2) S acquisition genes encoding for a high-affinity sulfate transporter were significantly induced, while decreased transcription of genes for phycobilisome, photosystems I and II, cytochrome b6/f, and ATP synthase indicated reduced light-harvesting and photosynthetic activity; 3) S deprivation elicited transcriptional responses associated with general growth arrest and stress; 4) A large number of genes regulated by S availability encode hypothetical proteins or proteins of unknown function; 5) Hydrogenase structural and maturation accessory genes were not identified as differentially expressed, even though increased hydrogen evolution was observed. The expression profiles recorded by using this oligonucleotide-based microarray platform revealed that during transition from the condition of plentiful sulfur to no sulfur, Synechocystis undergoes coordinated transcriptional changes, including genes whose products are involved in sensing nutrient limitations and tuning bacterial metabolism. The transcriptional profile of the nutrient limitation was dominated by decrease in abundances of many transcripts. However, these changes were unlikely due to the across-the-board, non-specific shut down of transcription in a condition of growth arrest. Down-regulation of transcripts encoding proteins whose function depends on a cellular sulfur status indicated that the observed repression has a specific regulatory component. The repression of certain sulfur-related genes was paralleled by activation of genes involved in internal and external S scavenging. Keywords: stress response, time course Synechocystis sp. PCC 6803 was grown photoautotrophically in BG-11 medium supplemented with 8mM NaHCO3 and buffered with 10mM HEPES (pH 7.4). The cells were grown in 250ml flasks at 32oC under a light intensity of 25µmol photons m-2 s-1. Cultures were bubbled with sterile air containing 1% (v/v) CO2. Log phase cells (OD730nm=0.6) were harvested by centrifugation (2000×g for 12 min) washed once and then re-suspended in sulfate-free media (MgSO4 replaced by the same molarity of MgCl2). In addition, all S-containing trace metals in BG-11 were replaced by non-S containing metals. Cells were harvested and fixed for microarray analysis by adding 10% (v/v) ice-cold 5% phenol in ethanol stop solution at the following time points: before S-depravation (time 0, control), 1, 3, 6, 12, 24, 48 and 72 hr after S-depravation. S-deprivation with HEPES buffering control experiment was performed as described above, except that HEPES buffer was used upon sulfate removal. Bacterial samples for a time course were taken at time 0, 1, 12 and 24 hrs after sulfate withdrawal. Growth stage control experiment was done in parallel with S deprivation experiments. Samples were taken at 0, 1, 2.5, 4, 7, 11 and 48 hr after OD730nm reached 0.60. All the experiments were done in biological replicates.
Project description:Although some mechanisms are known how plant growth beneficial bacteria help plants to grow under stressful conditions, we still know little how the metabolism of host plants and bacteria is coordinated during the establishment of functional interaction. In the present work, using single and dual transcriptomics, we studied the reprograming of metabolic and signaling pathways of Enterobacter sp. SA187 with Arabidopsis thaliana during the change from free-living to endophytic host-microbe interaction. We could identify major changes in primary and secondary metabolic pathways in both the host and bacteria upon interaction, with an important role of the sulfur metabolism and retrograde signaling in mediating plant resistance to salt stress. Also, we studied the effect of SA187 endogenous compounds and its role on sulfur metabolism and consequently salt tolerance. These data should help future research in the field of beneficial plant-microbe interactions for developing sophisticated strategies to improve agriculture of crops under adverse environmental conditions. transcriptome of Arabidopsis thaliana organs with beneficial microbe, beneficial microbe endogenous compound, and ethylene precursor
Project description:In rainbow trout, type A spermatogonia can be split into SP cells and non-SP cells by the ability to exclude Hoechst 33342 dye (H33342). The H33342 fluorescence of SP cells are lower than that of non-SP cells, after H33342 staining. To investigate whether SP cells were transcriptomically distinct from non-SP cells, we compared the transcriptome of these cells. We used fluorescence-activated cell sorting (FACS) to isolate SP cells and non-SP cells from the type A spermatogonia in rainbow trout.
Project description:Caves are populated with a diverse fauna of highly adapted species that tend to exhibit a consistent suite of both regressive and constructive trait modifications. Because molecular studies of cave adaptation have largely concentrated on vertebrate models, our ability to recognize universalities in the genetic trajectories underlying cave adaptation remains limited. We have initiated efforts to elucidate the molecular evolution of the flightless small carrion beetle Ptomaphagus hirtus (Ptomaphagus hirtus), which represents one of the highly endemic signature inhabitants of the Mammoth Cave system of Kentucky. Ptomaphagus hirtus has been considered blind despite the presence of lateral eye rudiments. However, analysis of the Ptomaphagus hirtus adult head transcriptome by deep RNA sequencing reveals the conservation and expression of all essential insect phototransduction genes including a single long wavelength-sensitive opsin. Consistent with the preservation of visual ability, Ptomaphagus hirtus expresses all core members of the clock gene network and exhibits a similar degree of negative phototaxis as does a closely related flight-active species in light-dark choice assays. The structural reduction of the peripheral Ptomaphagus hirtus visual system is reflected by the lack of five eye pigmentation specific genes in the head transcriptome. Taken together our data suggest that wavelength contingent and probably also spatial vision have been lost in Ptomaphagus hirtus, while irradiance vision and contingent behavioral modules have remained preserved. We predict that the adaptive state of Ptomaphagus hirtus is representative for a large number of microphthalmic species adapted to the twilight zone of caves and other subterranean habitats Poly(A)+ transcripts were isolated from a pooled sample of 25 adult Ptomaphagus hirtus heads, reverse transcribed and sequenced on the Illumina GAII