Pseudomonas aeruginosa chronically colonizes the lungs of individuals with CF, where it reaches high cell densities and produces a battery of virulence factors. Upon infection, a single strain of P. aeruginosa can colonize an individuals lungs throughout his or her lifetime. To understand the evolution of P. aeruginosa during chronic lung infection, we conducted both genotypic and phenotypic analyses on clinical isogenic strains obtained from the lungs of three different individuals with CF. These strains were isolated over a period of approximately ten years and possess phenotypes that are commonly observed in isolates from the CF lung, such as the antibiotic resistant dwarf and mucoid phenotypes. Microarray analyses were carried out on isolates grown in a chemically defined medium that mimics the nutritional environment of the CF lung, synthetic CF sputum medium (SCFM).
Parallel evolution in Pseudomonas aeruginosa over 39,000 generations in vivo.
Time
View SamplesSelective serotonin reuptake inhibitors (SSRIs) are commonly prescribed antidepressant drugs in pregnant women. Given that SSRIs can cross the placental and blood-brain barriers, these drugs potentially affect serotonergic neurotransmission and neurodevelopment in the fetus. Although no gross SSRI-related teratogenic effect has been reported, infants born following prenatal exposure to SSRIs have a higher risk for various behavioral abnormalities. Therefore, we examined the effects of prenatal fluoxetine, the most commonly prescribed SSRI, on social and cognitive behavior in mice. Intriguingly, chronic in utero fluoxetine treatment impaired working memory and social novelty recognition in adult males with augmented spontaneous inhibitory synaptic transmission onto the layer 5 pyramidal neurons in the medial prefrontal cortex (mPFC). Moreover, fast-spiking interneurons in the layer 5 mPFC exhibited enhanced basal intrinsic excitability, augmented serotonin-induced neuronal excitability, and increased inhibitory synaptic transmission onto the layer 5 pyramidal neurons due to augmented 5-HT2A receptor (5-HT2AR) signaling. More importantly, the observed behavioral deficits of in utero fluoxetine-treated mice could be reversed by acute systemic application of 5-HT2AR antagonist. Taken together, our findings support the notion that alterations in serotonin-mediated inhibitory neuronal modulation result in reduced cortical network activities and cognitive impairment following prenatal exposure to SSRIs.
No associated publication
Sex, Specimen part, Treatment
View SamplesThe Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.
VASCULAR-RELATED NAC-DOMAIN7 directly regulates the expression of a broad range of genes for xylem vessel formation.
Age, Specimen part, Treatment
View SamplesThe expression of four transcription factors (OCT3/4, SOX2, KLF4, and c-MYC) can reprogram mouse as well as human somatic cells to induced pluripotent stem (iPS) cells. Expression of the c-MYC, also known as an oncogene, might induce carcinogenesis and thus, iPS cells produced with the use of c-MYC transduction cannot be used for human therapeutic applications. Furthermore, reprogramming efficiency was significantly reduced in the absence of c-MYC transduction. Here, we generated iPS cells from mesenchymal stromal cells (MSCs) derived from human third molars (wisdom teeth) by retroviral transduction of OCT3/4, SOX2, and KLF4 without c-MYC. Interestingly, clonally expanded MSCs, named 10F-15, could be used for iPS cell generation with 100-fold higher efficiency compared to that of other clonally expanded MSCs and human dermal fibroblasts. These iPS cells resembled human embryonic stem (ES) cells in many aspects, including morphology, ES markers expression, global gene expression, epigenetic states, and the ability to differentiate into the three germ layers in vitro and in vivo. Because human third molars are discarded as clinical waste, our data indicate that MSCs isolated from human third molars are a valuable cell source for the generation of iPS cells.
Induction of pluripotent stem cells from human third molar mesenchymal stromal cells.
Specimen part, Cell line
View SamplesR1R2R3-Myb proteins represent an evolutionarily conserved class of Myb family proteins important for cell cycle regulation and differentiation in eukaryotic cells. In plants, this class of Myb proteins are believed to play important roles in cell cycle regulation through transcriptional regulation of G2/M phase-specific genes by binding to common cis-elements, called MSA elements. In Arabidopsis thaliana, MYB3R1 and MYB3R4 act as transcriptional activators and positively regulate cytokinesis by activating transcription of KNOLLE, which encodes a cytokinesis-specific syntaxin. Here, we show that the double mutation myb3r1 myb3r4 causes pleiotropic developmental defects, some of which are due to deficiency of KNOLLE whereas other are not, suggesting multiple target genes are involved. Consistently, microarray analysis of the double mutant revealed altered expression of many genes, among which G2/M-specific genes showed significant overrepresentation of the MSA motif and a strong tendency to be down-regulated by the double mutation. Our results demonstrate, on a genome-wide level, the importance of the MYB3R-MSA pathway for regulating G2/M-specific transcription. In addition, MYB3R1 and MYB3R4 may have diverse roles during plant development by regulating G2/M-specific genes with various functions, as well as genes possibly unrelated to the cell cycle.
Mutations in MYB3R1 and MYB3R4 cause pleiotropic developmental defects and preferential down-regulation of multiple G2/M-specific genes in Arabidopsis.
Age, Specimen part
View SamplesGenome-wide expression analysis of two circadian oscillatory mechanisms in the mouse liver
Genome-wide expression analysis reveals 100 adrenal gland-dependent circadian genes in the mouse liver.
No sample metadata fields
View SamplesTranscriptome comparison of E.coli W3110 (wild type), hha, ydgT, hns, stpA, hha_ydgT double and hns_stpA double mutant cells
Functions of the Hha and YdgT proteins in transcriptional silencing by the nucleoid proteins, H-NS and StpA, in Escherichia coli
No sample metadata fields
View SamplesGene expression profiling of primary mouse articular chondrocyte infected with recombinant adenovirus expressing mouse ZFP36 Ring Finger Protein Like 1(Zfp36l1) or recombinant adenovirus expressing mouse small hairpin RNA of Zfp36l1.
No associated publication
Specimen part
View SamplesPrimary cell wall (PCW) in plant mainly consists of three kinds of polysaccharides, cellulose, hemicellulose, and pectin. Although many genes encoding a variety of enzymes involved in synthesis, degradation, or modification of the PCW-related polysaccharides have been reported, regulation on expression of these PCW-related genes during PCW formation is still not fully understood. In this study, expression changes of PCW-related genes were analyzed during PCW regeneration in protoplasts.
No associated publication
No sample metadata fields
View SamplesGene expression profiling of primary mouse articular chondrocyte infected with recombinant adenovirus expressing the zinc transporter ZIP8 (SLC39A8) protein.
Pleiotropic roles of metallothioneins as regulators of chondrocyte apoptosis and catabolic and anabolic pathways during osteoarthritis pathogenesis.
Age, Specimen part, Treatment
View Samples