Our analysis of the sfr6 freezing-sensitive mutant (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.) and cls8 (unpublished) chilling-sensitive mutant of Arabidopsis, has revealed that the expression of certain cold-regulated genes is aberrant in both these mutants. In order to understand the molecular basis of chilling and freezing stress in Arabidopsis and also to determine commonalities and differences between these 2 different physiological stress-tolerance processes, we request transcriptome analysis for both of these mutants compared to wild type in one experiment, upon cold treatment and at ambient conditions. The sfr6 mutant shows the most severe phenotype with respect to cold gene expression, but is tolerant to chilling (Knight, H., Veale, E., Warren, G. J. and Knight, M. R. (1999). Plant Cell 11, 875-886.). However, it is unable to cold acclimate and hence is sensitive to freezing. The cls8 mutant, on the other hand, has a relatively mild phenotype relative to the cold-regulated genes we have examined, but is very sensitive to chilling temperatures (15 to 10 degree centigrade). It is thus likely that in cls8 we have not yet identified the genes which are most affected, and which account for the physiological phenotype. Both sfr6 and cls8 have been fine-mapped and are close to being cloned. The cls8 mutant has an altered calcium signature in response to cold which means it is likely to be affected in early signalling, e.g. cold perception itself.We will compare the expression profiles of genes in sfr6, cls8 and Columbia (parental line for both mutants), both at ambient, and after treatment with cold (5 degrees) for 3 hours. This timepoint is designed to capture both rapidly responding genes e.g. CBF/DREB1 transcription factors, and also more slow genes e.g. COR genes (KIN1/2 and LTI78). Pilot northerns confirm that this time point is suitable.This analysis will provide new insight into 2 novel genes required for tolerance to low temperature in Arabidopsis, and additionally will determine the nature of overlap between the separate processes of chilling and freezing tolerance.
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Specimen part
View SamplesThe sfr6-1 mutant of Arabidopsis has been shown to be defective in freezing tolerance and fails to express a number of cold-regulated genes to normal wild type levels. The aim of this experiment was to test whether two other mutant alleles, sfr6-2 and sfr6-3 showed similar defects in cold-inducible gene expression.
The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes.
Age
View SamplesCombinations of anticancer agents may have synergistic anti-tumor effects, but enhanced hematological toxicity often limit their clinical use. We examined whether microarray profiles could be used to compare early molecular responses following a single dose of agents administered individually with that of the agents administered in a combination. Six patterns of co-expressed genes were detected at the 1-hour time point which indicate regulatory expression of genes dependent on the order of the administration. When topotecan is given first, several signal transduction transcription factors associated with cancer or inactivation of a tumor suppressor were co-regulating gene expression. These results suggest alterations in histone biology, chromatin remodeling, DNA repair, bone regeneration, and respiratory and oxidative phosphorylation are among the prominent pathways modulated in bone marrow from animals treated with an oxaliplatin/topotecan combination.
Toxicogenomics profiling of bone marrow from rats treated with topotecan in combination with oxaliplatin: a mechanistic strategy to inform combination toxicity.
Sex, Age, Specimen part, Time
View SamplesThe response to growth hormone in humans is dependent on phenotypic, genetic and environmental factors. The present study in children with growth hormone deficiency (GHD) collected worldwide characterised gene-environment interactions on growth response to recombinant human growth hormone (r-hGH). Growth responses in children are linked to latitude, and we found that a correlation of latitude, summer daylight exposure (SDE) was a key environmental factor related to growth response to r-hGH. In turn growth response was determined by an interaction between both SDE and genes known to affect growth response to r-hGH. In addition analysis of associated networks of gene expression implicated a role for circadian clock pathways and specifically the developmental transcription factor NANOG. This work provides the first observation of gene-environment interactions in children treated with r-hGH.
Effect of summer daylight exposure and genetic background on growth in growth hormone-deficient children.
Sex, Age
View SamplesThe growth of the mammalian ovarian follicle requires the formation of a fluid filled antrum, and maturation and differentiation of the ovarian granulosa cells, largely under the control of Follicle Stimulating Hormone (FSH). Many follicles will regress and die by a process called atresia at this early antral stage. We therefore decided to analyse the gene expression profiles of granulosa cells cultured in the presence or absence of FSH and Tumour Necrosis Factor-alpha (TNF), an apoptotic factor, to simulate the key influences. Different concentratons of FSH and TNFa in granulosa culture were used to determine effective conditions via estradiol and progesterone production, and cell number.
The global effect of follicle-stimulating hormone and tumour necrosis factor α on gene expression in cultured bovine ovarian granulosa cells.
Specimen part, Treatment
View SamplesThe ability of transcriptional regulators to drive lineage conversion of somatic cells offers great potential for the treatment of human disease. While current research in this field is focused on the generation of induced pluripotent stem cells or direct lineage transdifferentiation, less attention has been paid to the possibility of reprogramming cells to produce cytokines, growth factors and hormones. To explore the concept of switching on specific target genes in heterologous cells, we developed a model system to screen candidate factors for their ability to activate the archetypal megakaryocyte-specific chemokine platelet factor 4 (PF4) in fibroblasts. We found that co-expression of the transcriptional regulators GATA1 and FLI1 resulted in a significant increase in levels of PF4, which became magnified over time. We also determined that inclusion of a third factor, TAL1, further enhanced upregulation of PF4 expression. Our study therefore identified of TAL1 as an important component in the combination of transcriptional regulators that contribute to megakaryocyte programming, and demonstrated that such combinations can be used to produce potentially beneficial chemokines in readily available heterologous cell types.
Partial reprogramming of heterologous cells by defined factors to generate megakaryocyte lineage-restricted biomolecules.
Time
View SamplesWe measured gene expression across the whole genome in a panel of lines selected for a wing shape trait (angular offset). The lines were created in separate experiments, originating from two widely separated populations, and including multiple replicates of one population, but all were created using the same selection regime and trait. Here we evaluate the data with two objectives: 1) to identify candidate wing shape genes for future testing and validation, and 2) to assess variation among lines in the outcome of identical selection regimes
Microarray analysis of replicate populations selected against a wing-shape correlation in Drosophila melanogaster.
No sample metadata fields
View SamplesWild type Arabidopsis thaliana Col-0 root cultures, were treated with fenclorim or 4-chloro-6-methyl-2-phenylpyrimidine dissolved in acetone to achieve a final concentration of 100uM. The final acetone concentration of 0.1% was replicated in control root cultures. Samples were taken at four and twenty-four hours post addition in biological triplicate. Root cultures were routinely maintained at 25C in the dark.
Xenobiotic responsiveness of Arabidopsis thaliana to a chemical series derived from a herbicide safener.
Specimen part
View SamplesNeuroanatomical methods enable high-resolution mapping of neural circuitry, but do not allow systematic molecular profiling of neurons based on their connectivity. Here, we report the development of a novel approach for molecularly profiling projective neurons. We show that ribosomes can be labeled with a camelid nanobody raised against GFP and that this system can be engineered to selectively capture translating mRNAs from cells expressing GFP. We generated a transgenic mouse encoding a nanobody-ribosomal protein fusion (Syn-NBL10) and used a retrograde virus (CAV) encoding GFP to immunoprecipitate ribosomes from projection neurons. This enabled us to profile neurons projecting to the nucleus accumbens. The current method provides a new means for profiling neurons based on their projections. Overall design: Translating mRNAs immunoprecipitated from neurons projecting to the nucleus accumbens. Each Input and IP sample corrspond to a pooled group of 6 mice.
Molecular profiling of neurons based on connectivity.
No sample metadata fields
View SamplesIn response to acute loss of the Ulp2 SUMO-specific protease, yeast become disomic for chromosome I (ChrI) and ChrXII. Here we report that ChrI disomy, which creates an adaptive advantage in part by increasing the dosage of the Ccr4 deadenylase, was eliminated by extended passaging. Loss of aneuploidy is often accompanied by mutations in essential SUMO-ligating enzymes, which reduced polySUMO-conjugate accumulation. The mRNA levels for almost all ribosomal proteins increases transiently upon initial loss of Ulp2, but elevated Ccr4 levels limit excess ribosome formation. Notably, extended passaging leads to increased levels of many small nucleolar RNAs (snoRNAs) involved in ribosome biogenesis, and higher dosage of three linked ChrXII snoRNA genes suppressed ChrXII disomy in ulp2? cells. Our data reveal that aneuploidy allows rapid adaptation to Ulp2 loss, but long-term adaptation restores euploidy. Cellular evolution restores homeostasis through countervailing mutations in SUMO-modification pathways and regulatory shifts in ribosome biogenesis. Overall design: In these comparisons, the ulp2? cells either carried a WT ULP2 plasmid or empty vector and were passaged for 50 or 500 generations. mRNA profiles of them were generated by sequencing, in triplicate, using Illumina HiSeq 2500 .
Distinct adaptive mechanisms drive recovery from aneuploidy caused by loss of the Ulp2 SUMO protease.
Subject
View Samples