Project description:To identify the molecular components involved in diatom cell division, global transcript level changes were monitored over the silicon-synchronized cell cycle the model diatom Thalassiosira pseudonana.
Project description:Phytoplankton and bacteria form the base of marine ecosystems and their interactions drive global biogeochemical cycles. The effect of bacteria and bacteria-produced compounds on diatoms range from synergistic to pathogenic and can affect the physiology and transcriptional patterns of the interacting diatom. Here, we investigate physiological and transcriptional changes in the marine diatom Thalassiosira pseudonana induced by extracellular metabolites of a known antagonistic bacterium Croceibacter atlanticus. Mono-cultures of C. atlanticus released compounds that inhibited diatom cell division and elicited a distinctive phenotype of enlarged cells with multiple plastids and nuclei, similar to what was observed when the diatom was co-cultured with the live bacteria. The extracellular C. atlanticus metabolites induced transcriptional changes in diatom pathways that include recognition and signaling pathways, cell cycle regulation, carbohydrate and amino acid production, as well as cell wall stability. Phenotypic analysis showed a disruption in the diatom cell cycle progression and an increase in both intra- and extracellular carbohydrates in diatom cultures after bacterial exudate treatment. The transcriptional changes and corresponding phenotypes suggest that extracellular bacterial metabolites, produced independently of direct bacterial-diatom interaction, may modulate diatom metabolism in ways that support bacterial growth.
Project description:Purpose:To identify genes and the molecular pathways involved in the regulation of muscle satellite cells (SCs) in mice exposure to running exercise, we performed RNA-Sequence of SCs in untrained (Con) and trained mice (Exe). Methods: mRNA profiles of SCs in untrained (Con) and trained mice (Exe) (running exercise, 4 days/week, 30 min/day at 12 m/min) were generated by deep sequencing, in quadruplicate, using Illumina HiSeq 2000. Results:Using an optimized data analysis workflow, we mapped about 9 million sequence reads per sample to the mouse genome (build mm10) and identified 9031 transcripts in SCs (the control and exercise group) with BWA workflow. Conclusions: Our results represent the first detailed analysis of SCs transcriptomes in mice exposure to running exercise and found that exercise regulated multiple mRNA pathways in SCs.
Project description:To investigate the properties of Sg spent culture supernatant (SCS) on the proliferation of periodontal pathogens and the expression of proinflammatory cytokines by human macrophages, epithelial cells, and gingival fibroblasts.
Project description:Using lineage-tracing in a well-established psoriasis-like mouse model with inducible epidermal deletion of c-Jun and JunB, we found that mutant HF-SCs survive and express a broad group of pro-inflammatory cytokines, whereas mutant inter-follicular epidermal cells (IFE) disappear over time. Mutant HF-SCs initiate epidermal hyperplasia and skin inflammation by priming neighboring non-mutant epidermal cells to acquire a psoriasis-like phenotype. To explore the molecular mechanisms that govern the behavior of these distinct mutant and non-mutant HF-SCs and IFE cell populations during psoriasis-like disease, RNA sequencing analyses of sorted GFP+, Tomato+ HF-SCs and b-KCs from DKO*-mT/mG mice.
Project description:Here, we examined the ramifications of between-species diversity by documenting the transcriptional response of three marine diatoms - Thalassiosira pseudonana, Fragilariopsis cylindrus, and Pseudo-nitzschia multiseries - to the onset of nitrate limitation of growth, a common limiting nutrient in the ocean. Less than 5% of orthologous genes, shared across the three diatoms, displayed the same transcriptional responses across species when growth was limited by nitrate availability. Orthologs, such as those involved in nitrogen uptake and assimilation, as well as carbon metabolism, were differently expressed across the three species. The two pennate diatoms, F. cylindrus and P. multiseries, shared 3,839 clusters without orthologs in the genome of the centric diatom T. pseudonana. A majority of these pennate-clustered genes, as well as the non-orthologous genes in each species, had minimal annotation information, but were often significantly differentially expressed under nitrate limitation, indicating their potential importance in the response to nitrogen availability. Despite these variations in the specific transcriptional response of each diatom, overall transcriptional patterns suggested that all three diatoms displayed a common physiological response to nitrate limitation that consisted of a general reduction in carbon fixation and carbohydrate and fatty acid metabolism and an increase in nitrogen recycling. Transcriptomes were collected for diatom cultures harvested at the onset of stationary phase in low nitrate media (55 M-NM-<M NaNO3, 212 M-NM-<M Na2SiO3, 72.4 M-NM-<M NaH2PO4) or during mid-exponential growth in nutrient-replete media (882 M-NM-<M NaNO3, 106 M-NM-<M Na2SiO3, 36.2 M-NM-<M NaH2PO4) in artificial seawater, maintaining three biological replicates per condition and per diatom (N=18). The SOLiD sequencer (version 4) was used to generate the transcriptomes and the SEAStAR software package was used to process the SOLiD reads and to calculate gene counts. Pooled counts for the nitrate-limited treatment were normalized to pooled counts for the nutrient-replete M-bM-^@M-^\controlM-bM-^@M-^] treatment to generate log fold changes in gene transcription using the R software package edgeR from Bioconductor.