This experiment contains the transcriptomic dataset that constitutes part of an integrated transcriptomic and proteomic study monitoring the response of exponential phase E. coli O157:H7 Sakai cultures upon an abrupt downshift in temperature and water activity (from 35°C aw 0.993 to 14°C aw 0.967).
Physiological Response of Escherichia coli O157:H7 Sakai to Dynamic Changes in Temperature and Water Activity as Experienced during Carcass Chilling.
Time
View SamplesFloral organ identities are specified by few transcription factors which act as master regulators. Subsequently, specification of organ axes programs the distribution of distinct tissue types within the organs that themselves develop unique identities. The C-class, AGAMOUS-clade MADS box genes are primary promoters of the gynoecium which is divided into a distal style and a subtending ovary along the apical-basal axis. We show that members of a clade of B3-domain transcription factors, NGATHA1 to NGA4 (NGA1-4), are expressed distally in all lateral organs, and all four have a redundant and essential role in style development. Loss of all four genes results in gynoecia where style is replaced by valve-like projections and a reduction in style-specific SHATTERPROOF1 (SHP1) expression. In agreement, floral misexpression of NGA1 promotes ectopic style and SHP1 expression. STYLISH1, an auxin biosynthesis inducer, conditionally activated NGA genes, which in turn, promoted distal expression of other STY genes in a putative positive feed back loop. Inhibited auxin transport or lack of YABBY1 gene activities resulted in a basally expanded style domain and broader expression of NGA genes. We speculate that early gynoecium factors delimit NGA gene response to an auxin-based signal, elicited by STY gene activity, to restrict the activation of style program to a late and distal carpel domain.
The NGATHA distal organ development genes are essential for style specification in Arabidopsis.
Age
View SamplesLeaves are flat determinate organs derived from indeterminate shoot apical meristems. The presence of a specific leaf meristem is debated, as anatomical features typical of meristems are not present in leaves. Here we demonstrate that multiple NGATHA (NGA) and CINCINNATA-class-TCP (CIN-TCP) transcription factors act redundantly to suppress activity of a leaf margin meristem in Arabidopsis thaliana, and that their absence confers persistent marginal growth of leaves, cotyledons and floral organs. The marginal meristem is activated by the juxtaposition of adaxial and abaxial domains and maintained by WOX homeobox transcription factors, but other margin elaboration genes are dispensable for its maintenance. This genetic framework parallels the morphogenetic program of shoot apical meristems and may represent a relic from an ancestral shoot system from which seed plant leaves evolved.
Active suppression of a leaf meristem orchestrates determinate leaf growth.
Specimen part
View SamplesBacteria respond to osmotic stress by a substantial increase in the intracellular osmolality, adjusting their cell turgor for altered growth conditions. Using E. coli as a model organism we demonstrate here that bacterial responses to hyperosmotic stress specifically depend on the nature of osmoticum used. We show that increasing acute hyperosmotic NaCl stress above ~1.0 Os kg-1 causes a dose-dependent K+ leak from the cell, resulting in a substantial decrease in cytosolic K+ content and a concurrent accumulation of Na+ in the cell. At the same time, isotonic sucrose or mannitol treatment (non-ionic osmotica) results in a gradual increase of the net K+ uptake. Ion flux data is consistent with growth experiments showing that bacterial growth is impaired by NaCl at the concentration resulting in a switch from net K+ uptake to efflux. Microarray experiments reveal that about 40% of up-regulated genes shared no similarity in their responses to NaCl and sucrose treatment, further suggesting specificity of osmotic adjustment in E. coli to ionic- and non-ionic osmotica The observed differences are explained by the specificity of the stress-induced changes in the membrane potential of bacterial cells highlighting the importance of voltage-gated K+ transporters for bacterial adaptation to hyperosmotic stress.
Ion transport and osmotic adjustment in Escherichia coli in response to ionic and non-ionic osmotica.
No sample metadata fields
View SamplesKrppel-like factor 9 (Klf9), a zinc-finger transcription factor, is implicated in the control of cell proliferation, cell differentiation and cell fate in brain and uterus. Using Klf9 null mutant mice, we have investigated the involvement of Klf9 in small intestine crypt-villus cell renewal and lineage determination. We report the predominant expression of Klf9 gene in small intestine smooth muscle (muscularis externa). Jejunums null for Klf9 have shorter villi, reduced crypt stem/transit cell proliferation, and altered lineage determination as indicated by decreased and increased numbers of Goblet and Paneth cells, respectively. A stimulatory role for Klf9 in villus cell migration was demonstrated by BrdU labeling. Results suggest that Klf9 controls the elaboration, from small intestine smooth muscle, of molecular mediator(s) of crypt cell proliferation and lineage determination, and of villus cell migration.
Dysregulation of intestinal crypt cell proliferation and villus cell migration in mice lacking Kruppel-like factor 9.
No sample metadata fields
View SamplesIn seed plants, leaves are born on radial shoots but unlike shoots they are determinate dorsiventral organs made of flat lamina. YABBY genes are found only in seed plants and in all cases studied, are expressed primarily in lateral organs and in a polar manner. Despite their simple expression, Arabidopsis plants lacking all YABBY gene activities have a wide range of morphological defects in all lateral organs as well as the shoot apical meristem. Here we show that leaves lacking all YABBY activities are initiated as dorsiventral appendages but fail to properly activate lamina programs. In particular, the activation of most CIN-TCPs does not commence, SAM-specific programs are reactivated, and a marginal leaf domain is not established. Altered distribution of auxin signalling and the auxin efflux carrier PIN1, highly reduced venation, initiation of multiple cotyledons, and gradual loss of the SAM accompany these defects. We suggest that YABBY functions were recruited to mould modified shoot systems into flat plant appendages by translating organ polarity into lamina specific programs that include marginal auxin flow and activation a maturation schedule directing determinate growth.
Differentiating Arabidopsis shoots from leaves by combined YABBY activities.
Specimen part
View SamplesMicroarray analysis was performed to examine potential differences in target gene expression of AE9a expressing low cells compared to AE9a expressing high cells. Potential contributing factors to AE9a induced leukemia were investigated.
Supraphysiologic levels of the AML1-ETO isoform AE9a are essential for transformation.
Specimen part
View SamplesGSM48315-GSM48332: Ten cells from C57Bl/6 male mouse bone marrow (SP or CD8 T cells) were sorted into individual wells of 96-well plates. The mRNA of these cells was amplified by the global single cell RT-PCR method and biotinylated targets were generated after optimal digestion with DNAse I.
Evidence for diversity in transcriptional profiles of single hematopoietic stem cells.
No sample metadata fields
View SamplesThe goal of this study was to investigate DNA methylation and gene expression changes in a zebrafish model of ICF Syndrome which were generated by mutation of ICF-gene zbtb24. Comparison of gene expression changes between wildtype and zbtb24 homozygous mutants revealed upregulation of interferon response genes following zbtb24 deletion. Upregulation of interferon response genes was blocked by mutation of the dsRNA helicase Mda5. Overall design: For RNA-seq, gene expression was compared in whole two-week-old zebrafish larvae that were wildtype or homozygous for the zbtb24mk22 mutant allele. We further performed RNA-Seq analysis in three-week-old zebrafish larvae that were WT, mda5mk29/mk29 , zbtb24mk22/mk22 and mda5mk29/mk29 ;zbtb24mk22/mk22. Three samples consisting of pools of 10 larvae were examined for each genotype. For ERRBS, DNA was separately isolated from the fins of three wildtype and three zbtb24mk22 homozygous mutant adults.
Pericentromeric hypomethylation elicits an interferon response in an animal model of ICF syndrome.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNA-34c is associated with emphysema severity and modulates SERPINE1 expression.
Sex, Age, Cell line
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