Most hepatocellular carcinomas in younger patients from Peru arise from non-cirrhotic livers. Histological examination of the non-tumor liver tissues highlights the presence of clear cell foci in a significant fraction of Peruvian patients with hepatocellular carcinoma.
Liver clear cell foci and viral infection are associated with non-cirrhotic, non-fibrolamellar hepatocellular carcinoma in young patients from South America.
Specimen part, Disease stage, Subject
View SamplesUV-B radiation affects leaf growth in a wide range of species. In this work, we demonstrate that UV-B levels present in solar radiation inhibits maize leaf growth without causing any other visible stress symptoms, including accumulation of DNA damage. We conducted kinematic analyses of cell division and expansion to understand the impact of UV-B radiation on these cellular processes. Our results demonstrate that the decrease in leaf growth is a consequence of a reduction in cell production, and a shortened growth zone (GZ) in UV-B irradiated leaves. To determine the molecular pathways involved in UV-B inhibition of leaf growth, we performed RNA sequencing on isolated GZ tissues of control and UV-B exposed plants. Our results show a link between the observed leaf growth inhibition and the expression of specific cell cycle and developmental genes, including Growth Regulating Factors (GRFs) and transcripts for proteins participating in different hormone pathways. Overall design: Factorial design with two factors: Treatment (control vs UV-B) x Zone I (0-1cm from base of the leaf), 2 (1-2cm from base of the leaf) and 3 (2-3cm from base of the leaf), 3 replicates
UV-B Inhibits Leaf Growth through Changes in Growth Regulating Factors and Gibberellin Levels.
Specimen part, Subject
View SamplesLigand-mediated activation of the nuclear hormone receptor PPAR gamma lowers blood pressure and improves glucose tolerance in humans. Two naturally occurring mutations (P467L, V290M) in the ligand binding domain of PPAR gamma have been described in humans that lead to severe insulin resistance and hypertension. Experimental evidence suggests that these mutant versions of PPAR gamma act in a dominant negative fashion. To better understand the molecular mechanisms underlying PPAR gamma action in the vasculature, we determined the gene expression patterns in mouse aorta in response to activation or interference with the PPAR gamma signaling pathway.
Bioinformatic analysis of gene sets regulated by ligand-activated and dominant-negative peroxisome proliferator-activated receptor gamma in mouse aorta.
No sample metadata fields
View SamplesP1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using pericarps at two different stages, 14 and 25 days after pollination (DAP). High-throughput sequencing using the Illumina platform resulted in the generation of ~20 million high quality reads, from which ~90% aligned to the recently completed maize genome sequence corresponding to ~5 million reads for each one of the four samples. Overall design: Examination of two different RNA samples from two different stages of maize pericarp tissues.
A genome-wide regulatory framework identifies maize pericarp color1 controlled genes.
Specimen part, Subject
View SamplesP1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using from maize silks obtained at 2-3 days after emergence. High-throughput sequencing using the Illumina platform resulted in the generation of ~14 million high quality reads, corresponding to ~7 million reads for each sample, from which 76% aligned to the maize genome. Overall design: Examination of two different RNA samples from maize silks obtained at 2-3 days after emergence
A genome-wide regulatory framework identifies maize pericarp color1 controlled genes.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Osmotic stress induces phosphorylation of histone H3 at threonine 3 in pericentromeric regions of Arabidopsis thaliana.
Age, Specimen part
View SamplesHistone phosphorylation plays key roles in stress-induced transcriptional reprogramming in metazoans but its function(s) in land plants has remained relatively unexplored. Here we report that an Arabidopsis mutant defective in At3g03940 and At5g18190, encoding closely related Ser/Thr protein kinases, shows pleiotropic phenotypes including dwarfism and hypersensitivity to osmotic/salt stress. The double mutant has reduced global levels of phosphorylated histone H3 threonine 3 (H3T3ph), which are not enhanced, unlike the response in the wild type, by drought-like treatments. Genome-wide analyses revealed increased H3T3ph, slight enhancement in trimethylated histone H3 lysine 4 (H3K4me3), and a modest decrease in histone H3 occupancy in pericentromeric/knob regions of wild type plants under osmotic stress. However, despite these changes in heterochromatin, transposons and repeats remained largely transcriptionally repressed. In contrast, this reorganization of heterochromatin was mostly absent in the double mutant, which even under normal conditions exhibited lower H3T3ph levels in pericentromeric regions, and a few transposons and repeat sequences showed modest transcriptional activation. Interestingly, within actively transcribed protein-coding genes, H3T3ph density was minimal in 5 genic regions, coincidental with a peak of H3K4me3 accumulation. This pattern was not affected in the double mutant, implying the existence of additional H3T3 protein kinases in Arabidopsis. Our results suggest that At3g03940 and At5g18190 are involved in the phosphorylation of H3T3 in pericentromeric/knob regions and that this repressive epigenetic mark may be important for maintaining proper heterochromatic organization and, possibly, chromosome function(s).
Osmotic stress induces phosphorylation of histone H3 at threonine 3 in pericentromeric regions of Arabidopsis thaliana.
Age, Specimen part
View SamplesWe used expression quantitative trait locus mapping in the laboratory rat (Rattus norvegicus) to gain a broad perspective of gene regulation in the mammalian eye and to identify genetic variation relevant to human eye disease. Of >31,000 gene probes represented on an Affymetrix expression microarray, 18,976 exhibited sufficient signal for reliable analysis and at least 2-fold variation in expression among 120 F2 rats generated from an SR/JrHsd x SHRSP intercross. Genome-wide linkage analysis with 399 genetic markers revealed significant linkage with at least one marker for 1,300 probes (alpha = 0.001; estimated empirical false discovery rate = 2%). Both contiguous and noncontiguous loci were found to be important in regulating mammalian eye gene expression. We investigated one locus of each type in greater detail and identified putative transcription-altering variations in both cases. We found an inserted cREL binding sequence in the 5' flanking sequence of the Abca4 gene associated with an increased expression level of that gene, and we found a mutation of the gene encoding thyroid hormone receptor beta 2 associated with a decreased expression level of the gene encoding short-wave sensitive opsin (Opn1sw). In addition to these positional studies, we performed a pairwise analysis of gene expression to identify genes that are regulated in a coordinated manner and used this approach to validate two previously undescribed genes involved in the human disease Bardet-Biedl syndrome. These data and analytic approaches can be used to facilitate the discovery of additional genes and regulatory elements involved in human eye disease.
Regulation of gene expression in the mammalian eye and its relevance to eye disease.
No sample metadata fields
View SamplesMurine pancreatic beta cell line MIN6 was growth at two different concentrations of glucose (22,2 and 5,5 mM of glucose), 37C, 5% CO2 and was treated at four different concentrations of human amylin (0, 1, 10 and 20 uM) during three different times (2, 12 and 24 hours)
Impairment of the ubiquitin-proteasome pathway is a downstream endoplasmic reticulum stress response induced by extracellular human islet amyloid polypeptide and contributes to pancreatic beta-cell apoptosis.
No sample metadata fields
View SamplesImpaired DNA replication is a hallmark of cancer and a cause of genomic instability. We report that, in addition to causing genetic change, impaired DNA replication during embryonic development can have major epigenetic consequences for a genome. In a genome-wide screen, we identified impaired DNA replication as causing increased expression from a repressed transgene in Caenorhabditis elegans. The acquired expression state behaved as an “epiallele,” being inherited for multiple generations before fully resetting. Derepression was not restricted to the transgene but was caused by a global reduction in heterochromatin-associated histone modifications due to the impaired retention of modified histones on DNA during replication in the early embryo. Impaired DNA replication during development can therefore globally derepress chromatin, creating new intergenerationally inherited epigenetic expression states. Overall design: 3 replicates of div-1 mutant worms and N2 wild type worms
Impaired DNA replication derepresses chromatin and generates a transgenerationally inherited epigenetic memory.
Specimen part, Subject
View Samples