In chicks, the avian homologue of the early growth response protein-1 (ZENK) has been shown to be increased in a special cell type of the retina, the glucagonergic amacrine cells, under conditions that lead to a reduction in eye growth (myopic defocus, recovery of myopia) and decreased under conditions that enhance ocular growth (hyperopic defocus, form-deprivation). The investigation of Egr-1 knock-out mice showed that homozygous knock-out mice with no functional Egr-1 protein developed relative axial myopia at the age of 42 and 56 days, compared to heterozygous- and wildtype Egr-1 knock-out mice.
Microarray analysis of retinal gene expression in Egr-1 knockout mice.
Sex, Age, Specimen part
View SamplesThe retina plays an important regulatory role in ocular growth. To screen for new retinal candidate genes that could be involved in the inhibition of ocular growth, we used chick microarrays to analyze the changes in retinal mRNA expression after myopic defocus was imposed by positive lens-wear.
Microarray analysis of retinal gene expression in chicks during imposed myopic defocus.
Sex, Age
View SamplesTo identify genes that are regulated by SERF1, we performed expression profiling on roots of serf1 and wild-type plants under standard growth conditions.
SALT-RESPONSIVE ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice.
Specimen part
View SamplesTo understand the effect of high and low GA levels on plant metabolism and development in Arabidopsis we made use of the GA biosynthesis inhibitor paclobutrazol (PBZ) and exogenously applied GA. The whole genome response at the translation level was assessed by immunopurification of polysomes from PBZ- and GA treated plants expressing FLAG-tagged ribosomal protein L18 (RPL18B). Polysomal associated RNA was isolated and subjected to affymterix ATH1 CHIP analysis. A total of 140 genes were statistically determined to be differentially translated after GA treatment whereas 89 genes where affected PBZ treatment. Our analysis revealed that GA and PBZ have opposing effects on the expression of cell wall and wax layer biosynthesis related genes. In addition, many genes involved in secondary metabolism are upregulated upon PBZ treatment. A set of SAUR-like genes important for mediating auxin responses are downregulated by PBZ, which is of interest to coordinatian of GA levels with growth and development. Interestingly, GA treatment induces the upregulation of transcription factors related to plant defense and senescence, which is in agreement with the early flowering upon GA treatment. Our study provides a first picture of the response of Arabidopsis to altered GA levels at the translation level, and thus will be valuable for understanding gene regulation at the polysome level.
Translatome and metabolome effects triggered by gibberellins during rosette growth in Arabidopsis.
Specimen part, Treatment
View SamplesSTO2 is a novel MYB like protein which belongs to one of the most important transcription factors in planta.
Salt-Related MYB1 Coordinates Abscisic Acid Biosynthesis and Signaling during Salt Stress in Arabidopsis.
Specimen part
View SamplesSerum response factor (SRF), a MADS-box transcription factor, is essential for murine embryonic development and for the function of muscle cells and neurons. SRF and its transcriptional co-factors are broadly expressed. To determine the in vivo role of SRF in developing lymphocytes we specifically inactivated the murine Srf gene during T or B cell development using lymphocyte-specific Cre transgenic mouse lines. T cell-specific Srf deletion led to a severe block in thymocyte development at the transition from double to single positive stage. The few residual T cells detectable in the periphery retained at least one functional Srf allele, thereby demonstrating the importance of SRF in T cell development. In contrast, deletion of Srf in developing B cells did not interfere with the growth and survival of B cells in general, yet led to a complete loss of marginal zone B cells and a marked reduction of the CD5+ B cell subset. Our study also revealed a contribution of SRF to the expression of the surface molecules IgM, CD19, and the chemokine receptor 4 in B lymphocytes.
Serum response factor contributes selectively to lymphocyte development.
Specimen part
View SamplesTo determine the role of RPX on cell proliferation and organ development, we performed microarray experiments in search of RPX target genes by using an estradiol-inducible RPXC protein.
An upstream regulator of the 26S proteasome modulates organ size in Arabidopsis thaliana.
Specimen part
View SamplesThe ts-p53 E285K protein is a rare p53 mutant with temperature-sensitive (ts) loss of function characteristics. In cancer cells, which express ts-p53 E285K intriniscally, endogenous wild type p53 activity is reconstituted by appropriate cultivation temperature (permissive condition). At non-appropriate cultivation temperature (restrictive condition) this p53 mutant is inactive. The present study took advantage of this mechanism and employed IPH-926 lobular breast cancer cells and BT-474 ductal breast cancer cells, which both harbor endogenous ts-p53 E285K, for the transcriptional profiling of p53-responsive genes. This new approach eliminated the need for genetic modification or cytotoxic stimulation to achive a p53 response in the cells being investigated .
IPH-926 lobular breast cancer cells harbor a p53 mutant with temperature-sensitive functional activity and allow for profiling of p53-responsive genes.
Specimen part, Cell line, Treatment
View SamplesFloodings already have a nearly 60% share in the worldwide damage to crops provoked by natural disasters. Climate change will cause plants to be even more frequently exposed to oxygen limiting conditions (hypoxia) in the near future due to heavy precipitation and concomitant waterlogging or flooding events in large areas of the world. Although the homeostatic regulation of adaptive responses to low oxygen stress in plants is well described, it remained unknown by which initial trigger the molecular response to low-oxygen stress is activated. Here, we show that a hypoxia-induced decline of the ATP level of the cell reduces LONG-CHAIN ACYL-COA SYNTHETASE (LACS) activity, which leads to a shift in the composition of the acyl-CoA pool. High oleoyl-CoA levels release the transcription factor RELATED TO APETALA 2.12 (RAP2.12) from its interaction partner ACYL-COA BINDING PROTEIN (ACBP) at the plasma membrane to induce low oxygen-specific gene expression. We show that different acyl-CoAs provoke unique molecular responses revealing a novel role as cellular signalling component also in plants. In terms of hypoxia signalling, dynamic acyl-CoA levels integrate the cellular energy status into the oxygen signalling cascade with ACBP and RAP2.12 being the central hub. The conserved nature of the ACBP:RAP2.12 module in crops and the novel mechanistic understanding of how low-oxygen stress responses are initiated by oleoyl-CoA in plants provide useful leads for enhancing future food security. Overall design: 1 control and 3 treatments with different forms of acyl-CoA in triplicate biological replicates
Low-oxygen response is triggered by an ATP-dependent shift in oleoyl-CoA in <i>Arabidopsis</i>.
Specimen part, Treatment, Subject
View SamplesGene expression is tightly linked to histone acetylation on lysine residues that can be recognized by bromodomains. The testis-specific bromodomain protein tBRD-1 is essential for male fertility and might act as a co-factor of testis-specifc TAFs. Here, we perform microarray analyses and demonstrate that tBRD-1 selectively controls gene expression in male germ cells
tBRD-1 selectively controls gene activity in the Drosophila testis and interacts with two new members of the bromodomain and extra-terminal (BET) family.
Specimen part
View Samples