Project description:RNase III is a ribonucleases that recognizes and cleaves double-stranded RNA. RNase III has been known be involved in rRNA processing, but has many additional roles controlling both expression and RNA turnover of specific messages. Many organisms have just one RNase III while some have both a full length RNase III and a mini-III that lacks the double-stranded RNA binding domain. The cyanobacteria Synechococcus sp. PCC 7002 has three homologs of RNase III that are unessential even when deleted in combination. We were interested what coding regions these RNase III enzymes were influencing and if they had redundant or distinct specificities. To address these questions we collected samples for RNA-sequencing from WT, the single, double, and triple RNase III mutants in triplicate. Approximately 20% of genes were differentially expressed in various mutants with some operons and regulons showing complex changes in expression levels between mutants. We describe the role of two RNase III’s in 23S rRNA maturation, and show how the third is involved in copy number regulation of one of the six plasmids (pAQ3). Purified enzymes were capable of cleaving some E. coli RNase III target sequences, highlighting the remarkably conserved substrate specificity between organisms yet complex regulation of gene expression.
Project description:Protein expression in Staphylococcus sp. NIOSBK35 isolated from marine environment (mangrove sediments) to different concentrations of arsenic (III)
Project description:The genomic loci occupied by RNA polymerase (pol) III have been characterized in human culture cells by genome-wide chromatin immunoprecipitation experiments followed by deep sequencing (ChIP-Seq). These studies have in particular shown that only about 40 % of the annotated 622 human tRNA genes and pseudogenes are occupied by pol III, and that these genes are often in regions of open chromatin rich in active pol II transcription units. Here we have used ChIP-Seq to characterize pol III-occupied loci in a differentiated tissue, the mouse liver. Our studies define the mouse liver pol III-occupied loci and point to a conserved pol III-occupied mammalian interspersed repeat (MIR) as a potential regulator of a pol III subunit-encoding gene. They reveal that synteny relationships can be established between a number of human and mouse pol III genes, and that the expression levels of these genes are significantly linked. They establish that variations within the A and B promoter boxes, as well as the strength of the terminator sequence can strongly affect pol III occupancy of tRNA genes. They reveal correlations with various genomic features that together describe the pol III occupancy scores over some 50% of tRNA genes. In mouse liver, pol III-occupied loci represented in the NCBI37/mm9 genome assembly comprise fifty 5S genes, fourteen known non-tRNA genes, nine 4.5S genes, and some twenty nine SINEs. In addition, out of the 433 annotated tRNA genes, half are occupied by pol III. Transfer RNA gene expression levels reflect both an underlying genomic organization that is conserved in dividing human culture cells and resting mouse liver cells, and the particular promoter and terminator strengths of individual genes. 12 samples examinded, 4 on pol III, 2 on pol II, 2 on H3K4me3, 2 on H3k36me3, 2 input samples.
Project description:In humans there are two surfactant protein A (SP-A) functional genes SFTPA1 and SFTPA2 encoding innate immune molecules, SP-A1 and SP-A2, respectively, with numerous genetic variants each. SP-A interacts and regulates many of the functions of alveolar macrophages (AM). It is shown that SP-A variants differ in their ability to regulate the AM miRNome in response to oxidative stress (OxS). Because humans have both SP-A gene products, we were interested to determine the combined effect of co-expressed SP-A1/SP-A2 (co-ex) in response to ozone (O3) induced OxS on AM miRNome. Human transgenic (hTG) mice, carrying both SP-A1/SP-A2 (6A2/1A0, co-ex) and SP-A- KO were utilized. The hTG and KO mice were exposed to filtered air (FA) or O3 and miRNA levels were measured after AM isolation with or without normalization to KO. We found: (i) The AM miRNome of co-ex males and females in response to OxS to be largely downregulated after normalization to KO, but after Bonferroni multiple comparison analysis only in females the AM miRNome remained significantly different compared to control (FA); (ii) The targets of the significantly changed miRNAs were downregulated in females and upregulated in males; (iii) Several of the validated mRNA targets were involved in pro-inflammatory response, anti-apoptosis, cell cycle, cellular growth and proliferation; (iv) The AM of SP-A2 male, shown, previously to have major effect on the male AM miRNome in response to OxS, shared similarities with the co-ex, namely in pathways involved in the pro-inflammatory response and anti-apoptosis but also exhibited differences with the cell-cycle, growth, and proliferation pathway being involved in co-ex and ROS homeostasis in SP-A2 male. We speculate that the presence of both gene products versus single gene products differentially impact the AM responses in males and females in response to OxS.
Project description:The genomic loci occupied by RNA polymerase (pol) III have been characterized in human culture cells by genome-wide chromatin immunoprecipitation experiments followed by deep sequencing (ChIP-Seq). These studies have in particular shown that only about 40 % of the annotated 622 human tRNA genes and pseudogenes are occupied by pol III, and that these genes are often in regions of open chromatin rich in active pol II transcription units. Here we have used ChIP-Seq to characterize pol III-occupied loci in a differentiated tissue, the mouse liver. Our studies define the mouse liver pol III-occupied loci and point to a conserved pol III-occupied mammalian interspersed repeat (MIR) as a potential regulator of a pol III subunit-encoding gene. They reveal that synteny relationships can be established between a number of human and mouse pol III genes, and that the expression levels of these genes are significantly linked. They establish that variations within the A and B promoter boxes, as well as the strength of the terminator sequence can strongly affect pol III occupancy of tRNA genes. They reveal correlations with various genomic features that together describe the pol III occupancy scores over some 50% of tRNA genes. In mouse liver, pol III-occupied loci represented in the NCBI37/mm9 genome assembly comprise fifty 5S genes, fourteen known non-tRNA genes, nine 4.5S genes, and some twenty nine SINEs. In addition, out of the 433 annotated tRNA genes, half are occupied by pol III. Transfer RNA gene expression levels reflect both an underlying genomic organization that is conserved in dividing human culture cells and resting mouse liver cells, and the particular promoter and terminator strengths of individual genes.
Project description:Corneal epithelial stem cells reside in the limbus that is the transitional zone between the cornea and conjunctiva, and are essential to maintain the homeostasis of corneal epithelium. However, their characterization is poorly understood. Therefore, we constructed gene expression profiles of limbal epithelial SP and non-SP cell using RNA-sequencing. As a result, limbal epithelial SP cells have immature cell phenotypes with endothelial/mesenchymal cell markers, while limbal epithelial non-SP cells have epithelial progenitor cell markers.
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