Project description:Engineered nanoparticles (ENPs) are increasingly used to generate innovative industrial and medical goods. Because of their broad applications, they form a new class of pollutants with potential eco-toxicological impacts on marine ecosystems. Attempting to evaluate the risk, we investigated the toxicity of Iron and Zinc oxide ENPs on three picophytoplanktonic strains of algae: Micromonas commoda, Ostreococcus tauri and Nannochloris sp. Microalgae responses are highly species-dependent, Micromonas commoda growth being severely impaired by both ENP types whereas Ostreococcus tauri or Nannochloris sp. are resistant. ZnO ENPs have higher toxicity than iron ENPs though growth of M. commoda was severely inhibited by Fe2O3 ENPs. Transcriptome-wide analysis after exposure of M. commoda to ENPs shows that the altered biological processes mainly take place in the cytoplasm and that the response to ENPs is largely metabolic in nature: stimulation of carbohydrate metabolism, light harvesting processes and alteration of the nitrogen pathway. In addition, a severe disruption of ribosome structure and translation processes is observed.
Project description:Puccinia graminis f. sp. tritici is the cause of wheat stem rust. A microarray was designed from genes predicted from the P. graminis f. sp. tritici genome assembly, and gene expression measured for four conditions which include wheat or barley infecting growth stages initiated by urediniospores. mRNA was prepared from fresh urediniospores, uredinospores germinated for 24 hr, wheat seedlings infected with urediniospores for 8 days, and barley seedlings infected with urediniospores for 8 days. The asexual uredinial infection cycle on wheat produces additional urediniospores, which can start new cycles of wheat infection and are readily spread by aerial transport. This expression data is further described in Duplessis et al, Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici
Project description:Puccinia graminis f. sp. tritici is the cause of wheat stem rust. A microarray was designed from genes predicted from the P. graminis f. sp. tritici genome assembly, and gene expression measured for four conditions which include wheat or barley infecting growth stages initiated by urediniospores. mRNA was prepared from fresh urediniospores, uredinospores germinated for 24 hr, wheat seedlings infected with urediniospores for 8 days, and barley seedlings infected with urediniospores for 8 days. The asexual uredinial infection cycle on wheat produces additional urediniospores, which can start new cycles of wheat infection and are readily spread by aerial transport. This expression data is further described in Duplessis et al, Obligate Biotrophy Features Unraveled by the Genomic Analysis of the Rust Fungi, Melampsora larici-populina and Puccinia graminis f. sp. tritici A total of 12 samples were analyzed, including three biological replicates of the four conditions.
Project description:Macrophages play fundamental roles in regulation of inflammatory responses to pathogens, resolution of inflammation and tissue repair, and maintenance of tissue homeostasis. The long (L) and short (S) isoforms of SP-R210/MYO18A, a macrophage receptor for surfactant protein A (SP-A) and C1q, regulate basal and inflammatory macrophage phenotype at multiple gene expression, translational, and subcellular levels in addition to their SP-A and C1q-mediated functions; disruption of L renders macrophages hyper-inflammatory, although the underlying mechanism had previously been unexplored. We questioned whether disruption of the L isoform would alter the global genomic responses. RNA sequencing analysis of SP-R210L(DN) macrophages revealed basal and influenza induced upregulation of genes associated with inflammatory pathways, including TLR, RIG-I, NOD, and cytoplasmic DNA signaling, whereas knockdown of both SP-R210 isoforms (L and S) only resulted in increased RIG-I and NOD signaling. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis showed increased genome-wide deposition of the pioneer transcription factor PU.1 in SP-R210L(DN) compared to WT cells. ChIP-seq analysis of histone H3 methylation showed alterations in both repressive (H3K9me3 and H3K27me3) and transcriptionally active (H3K9me3) histone marks. Influenza A virus (IAV) infection, which stimulates an array of cytosolic and TLR-mediated antiviral mechanisms, resulted in differential redistribution between proximal promoter and distal sites and decoupling of PU.1 binding from Toll-like receptor regulated gene promoters in SP-R210L(DN) cells. Our findings suggest that SP-R210L-deficient macrophages are poised with an open PU.1-primed chromatin conformation to rapidly respond to inflammatory and metabolic stimuli.
Project description:Micromonas implements a sustained non-photochemical quenching response to phosphate limitation, driven by light harvesting family protein LHCSR. This protein, allows stable growth under P-limitation and increased growth without major LCH adjustment as phosphate becomes more available. Proteomics results show this alga integrates unique strategies to optimize growth under dynamic ocean nutrient conditions.
Project description:Np63+ve cells are multipotent and maintain all epithelial cell lineages of the embryonic and adult salivary gland (SG). However, the molecular mechanisms by which Np63 regulates stem/progenitor (SP) cell populations in the SG remains elusive. To better understand Np63 s role in directing cell fate choices, here we have utilized Np63-null adult mice and primary salivary cell cultures to probe alterations in SP cell differentiation and function. Specifically, we have generated bulk RNA-seq and scRNA-seq data from Np63-null adult mice and p63 and H3K27Ac ChIP-seq data from primary salivary cell cultures. These genomic and epigenomic data sets were leveraged to interrogate altered SG cellular identities and differentiation states resulting from the loss of Np63. Our studies reveal that ablation of Np63 results in a loss of the SP cell population and skewed SG differentiation that is modulated by dysregulated TGF- /Activin signaling. Our findings offer new molecular revelations into the SP cell gene regulatory networks that are likely to be relevant for normal or diseased SG states.
Project description:We integrated genomic and transcriptomic analysis of a newly isolated obligate Methylomonas sp. DH-1 grown on methane and methanol. Comparative transcriptomic analysis between methane and methanol as a sole carbon source revealed different transcriptional responses of Methylomonas sp. DH-1, especially in C1 assimilation, the secondary metabolites pathways and the oxidative stress related genes