Combinatorial control of gene expression by the three yeast repressors Mig1, Mig2 and Mig3
Combinatorial control of gene expression by the three yeast repressors Mig1, Mig2 and Mig3.
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View SamplesAcquired imatinib resistance in chronic myelogenous leukemia (CML) can be the consequence of mutations in the kinase domain of BCR-ABL or increased protein levels. However, as in other malignancies, acquired resistance to cytostatic drugs is a common reason for treatment failure or disease progression. As a model for drug resistance, we developed a CML cell line resistant to cyclophosphamide (CP). Using oligonucleotide arrays, we examined changes in global gene expression. Selected genes were also examined by real-time PCR and flow cytometry. Neither the parent nor the resistant lines had mutations in their ATP binding domain. Filtering genes with a low-base line expression, a total of 239 genes showed significant changes (162 up- and 77 down-regulated) in the resistant clone. Most of the up-regulated genes were associated with metabolism, signal transduction, or encoded enzymes. The gene for aldehyde dehydrogenase 1 was over-expressed more than 2000 fold in the resistant clone. BCR-ABL was expressed in both cell lines to a comparable extent. When exposed to the tyrosine kinase inhibitors imatinib and nilotinib, both lines were sensitive. In conclusion, we found multiple genetic changes in a CML cell line resistant to CP related to metabolism, signal transduction or apoptosis. Despite these changes, the resistant cells retained sensitivity to tyrosine kinase inhibitors.
Comparative gene expression analysis of a chronic myelogenous leukemia cell line resistant to cyclophosphamide using oligonucleotide arrays and response to tyrosine kinase inhibitors.
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View SamplesIn this study the gene expression in cells infected with lytic and non-lytic variants of coxsackievirus B2 Ohio (CVB2O) were analyzed using next generation sequencing. This approach was selected with the purpose of elucidating the effects of lytic and non-lytic viruses on host cell transcription. Total RNA was extracted from infected cells, next generation sequencing was performed, and the reads were subsequently mapped against the human and CVB2O genomes. The amount of intracellular virions was measured, showing a relative amount of virus RNA 13 times higher in the cells infected with the lytic variant, vVP1Q164K, compared to cells infected by the non-lytic CVB2Owt. Furthermore, differential gene expression in the cells infected with the two viruses was identified and a number of genes singled out as possible keys to the answer of how the viruses interact with the host cells, resulting in lytic or non-lytic infections. Overall design: 4 samples, two samples of one strain, one sample of a different strain, and one control sample
The Transcriptome of Rhabdomyosarcoma Cells Infected with Cytolytic and Non-Cytolytic Variants of Coxsackievirus B2 Ohio-1.
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View SamplesUsing a mimic miR-200c was restored to an aggressive, Type 2 endometrial cancer cell line, Hec50
MicroRNA-200c mitigates invasiveness and restores sensitivity to microtubule-targeting chemotherapeutic agents.
Specimen part, Cell line
View SamplesPiwi proteins and Piwi-interacting small RNAs (piRNAs) have known functions in transposon silencing in the male germline of fetal and newborn mice. Both are also necessary for spermatogenesis in adult testes, however, their function here remains a mystery. Here, we use germ cell isolations and small RNA sequencing to show that most piRNAs in meiotic spermatocytes originate from clusters in intergenic non-repeat regions of DNA. The regulation of these piRNA clusters, including the processing of the precursor transcripts into individual piRNAs, is accomplished through mostly unknown processes. We present evidence for a regulatory mechanism for one such cluster, named cluster 1082B, located on chromosome 7 in the mouse genome, containing 788 unique piRNAs. The precursor transcript and individual piRNAs within the cluster are repressed by the Alkbh1 dioxygenase and the transcription repressor Tzfp, which are believed to be interaction partners in testis. We observe more than a thousand-fold upregulation of individual piRNAs in pachytene spermatocytes isolated from Alkbh1-/- and TzfpGTi/GTi testes. Repression is further supported by the identification of a 10 bp Tzfp recognition sequence contained within the precursor transcript. Downregulation of long interspersed elements 1 (LINE1) and intracisternal A-particle (IAP) transcripts in the Alkbh1-/- and TzfpGTi/GTi testes leads us to propose a potential role for the 1082B-encoded piRNAs in transposon silencing. Overall design: Characterization of small RNAs in mouse pachytene spermatocytes for wild-type (WT) and Alkbh1-/- and TzfpGTi/GTi, and mRNA in mouse pachytene spermatocytes for wild-type (WT) and Alkbh1-/-
Alkbh1 and Tzfp repress a non-repeat piRNA cluster in pachytene spermatocytes.
Specimen part, Subject
View SamplesIn this study, we describe the impact of genetic variation on transcript abundance in an F2 population of Arabidopsis thaliana. The RNA-seq resource generated by this study is suitable for expression quantitative trait locus (eQTL) mapping. From the aligned RNA-seq reads, and available genomic data for each of the parents of the cross, we imputed the genomes of each F2 individual (to allow genetic mapping of RNA abundance traits; briefly, genetic differences in aligned RNA-seq reads were used to impute each F2 genome). Our results show that heritable differences on gene expression can be detected using F2 populations (that is, single F2 plants), and shed light on the control of expression differences among strains of this reference plant. Overall design: 183 samples consisting of single F2 plants of a cross between Arabidopsis thaliana accessions 8230 and 6195 were generated. For each sample, RNA was collected from the aerial shoot at the 9th true leaf stage, and Illumina mRNA-seq libraries were constructed. Using these libraries, 50 bp single end RNA-seq Illumina reads were generated for each sample, and used to quantify gene expresison in each individual. The resulting expression phenotypes are suitable for genetic mapping of the control of gene expression differences in the species.
Epistatic and allelic interactions control expression of ribosomal RNA gene clusters in Arabidopsis thaliana.
Specimen part, Subject
View SamplesGrowth hormone signaling in hepatocytes is fundamentally important. Disruptions in this pathway have led to fatty liver and other metabolic abnormalities. Growth hormone signals through the JAK2/STAT5 pathway. Mice with hepatocyte specific deletion of STAT5 were previously shown to develop fatty liver. Our aim in this study was to determine the effect of deleting JAK2 in hepatocytes on liver gene expression. To do so, we generated animals with hepatocyte specific deletion of JAK2.
Abrogation of growth hormone secretion rescues fatty liver in mice with hepatocyte-specific deletion of JAK2.
Sex, Age, Specimen part
View SamplesTo understand the population genetics of structural variants (SVs), and their effects on phenotypes, we developed an approach to mapping SVs, particularly transpositions, segregating in a sequenced population, and which avoids calling SVs directly. The evidence for a potential SV at a locus is indicated by variation in the counts of short-reads that map anomalously to the locus. These SV traits are treated as quantitative traits and mapped genetically, analogously to a gene expression study. Association between an SV trait at one locus and genotypes at a distant locus indicate the origin and target of a transposition. Using ultra-low-coverage (0.3x) population sequence data from 488 recombinant inbred Arabidopsis genomes, we identified 6,502 segregating SVs. Remarkably, 25% of these were transpositions. Whilst many SVs cannot be delineated precisely, PCR validated 83% of 44 predicted transposition breakpoints. We show that specific SVs may be causative for quantitative trait loci for germination, fungal disease resistance and other phenotypes. Further we show that the phenotypic heritability attributable to sequence anomalies differs from, and in the case of time to germination and bolting, exceeds that due to standard genetic variation. Gene expression within SVs is also more likely to be silenced or dysregulated, as inferred from RNA-seq data collected from a subset of just over 200 of the MAGIC lines. This approach is generally applicable to large populations sequenced at low-coverage, and complements the prevalent strategy of SV discovery in fewer individuals sequenced at high coverage. Overall design: 209 samples consisting of different inbred lines from the Multiparent Advance Generation InterCross (MAGIC) population in the reference plant, Arabidopsis thaliana. For each sample, RNA was collected from the aerial shoot at the 4th true leaf stage, and Illumina mRNA-seq libraries were constructed (a single library was constructed with each line; that is, each MAGIC line is represented by one biological replicate). Using these libraries, which were non-stranded, paired-end 100 bp RNA-seq Illumina reads were generated for each sample, and used to quantify gene expresison in each MAGIC line. The resulting expression phenotypes are suitable for describing the impacts of genetic variation in the MAGIC line founders on the control of gene expression.
Genomic Rearrangements in <i>Arabidopsis</i> Considered as Quantitative Traits.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Glucocorticoids enhance muscle endurance and ameliorate Duchenne muscular dystrophy through a defined metabolic program.
Specimen part, Treatment
View SamplesExcessive or sustained glucocorticoid (GC) exposure causes muscle wasting. Paradoxically, moderate or transient GC exposure elicits ergogenic effects, evidenced by their widespread use as doping agents by endurance athletes and poorly understood efficacy in Duchenne muscular dystrophy (DMD), a genetic muscle wasting disease. While mechanisms underlying GC-mediated muscle wasting are well defined, the molecular basis for the latter remains unknown. In this arm of our studies, we compare expression profiles in quadriceps tissue from KLF15 transgenic (MTg) and non-Tg mice.
Glucocorticoids enhance muscle endurance and ameliorate Duchenne muscular dystrophy through a defined metabolic program.
Specimen part
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