153 research outputs found
iCanPlot: Visual Exploration of High-Throughput Omics Data Using Interactive Canvas Plotting
Increasing use of high throughput genomic scale assays requires effective visualization and analysis techniques to facilitate data interpretation. Moreover, existing tools often require programming skills, which discourages bench scientists from examining their own data. We have created iCanPlot, a compelling platform for visual data exploration based on the latest technologies. Using the recently adopted HTML5 Canvas element, we have developed a highly interactive tool to visualize tabular data and identify interesting patterns in an intuitive fashion without the need of any specialized computing skills. A module for geneset overlap analysis has been implemented on the Google App Engine platform: when the user selects a region of interest in the plot, the genes in the region are analyzed on the fly. The visualization and analysis are amalgamated for a seamless experience. Further, users can easily upload their data for analysis—which also makes it simple to share the analysis with collaborators. We illustrate the power of iCanPlot by showing an example of how it can be used to interpret histone modifications in the context of gene expression
S100B concentration in colostrums of Burkinabe and Sicilian women
The aim of this study is to determine the S100B concentration in colostrums of 51 Burkinabe and 30 Sicilian women, still living in their countries, and in case of a difference to search for its explanations, considering also ethnic differences
The enigmatic mitochondrial genome of Rhabdopleura compacta (Pterobranchia) reveals insights into selection of an efficient tRNA system and supports monophyly of Ambulacraria
<p>Abstract</p> <p>Background</p> <p>The Hemichordata comprises solitary-living Enteropneusta and colonial-living Pterobranchia, sharing morphological features with both Chordata and Echinodermata. Despite their key role for understanding deuterostome evolution, hemichordate phylogeny is controversial and only few molecular data are available for phylogenetic analysis. Furthermore, mitochondrial sequences are completely lacking for pterobranchs. Therefore, we determined and analyzed the complete mitochondrial genome of the pterobranch <it>Rhabdopleura compacta </it>to elucidate deuterostome evolution. Thereby, we also gained important insights in mitochondrial tRNA evolution.</p> <p>Results</p> <p>The mitochondrial DNA of <it>Rhabdopleura compacta </it>corresponds in size and gene content to typical mitochondrial genomes of metazoans, but shows the strongest known strand-specific mutational bias in the nucleotide composition among deuterostomes with a very GT-rich main-coding strand. The order of the protein-coding genes in <it>R. compacta </it>is similar to that of the deuterostome ground pattern. However, the protein-coding genes have been highly affected by a strand-specific mutational pressure showing unusual codon frequency and amino acid composition. This composition caused extremely long branches in phylogenetic analyses. The unusual codon frequency points to a selection pressure on the tRNA translation system to codon-anticodon sequences of highest versatility instead of showing adaptations in anticodon sequences to the most frequent codons. Furthermore, an assignment of the codon AGG to Lysine has been detected in the mitochondrial genome of <it>R. compacta</it>, which is otherwise observed only in the mitogenomes of some arthropods. The genomes of these arthropods do not have such a strong strand-specific bias as found in <it>R. compacta </it>but possess an identical mutation in the anticodon sequence of the tRNA<sub>Lys</sub>.</p> <p>Conclusion</p> <p>A strong reversed asymmetrical mutational constraint in the mitochondrial genome of <it>Rhabdopleura compacta </it>may have arisen by an inversion of the replication direction and adaptation to this bias in the protein sequences leading to an enigmatic mitochondrial genome. Although, phylogenetic analyses of protein coding sequences are hampered, features of the tRNA system of <it>R. compacta </it>support the monophyly of Ambulacraria. The identical reassignment of AGG to Lysine in two distinct groups may have occurred by convergent evolution in the anticodon sequence of the tRNA<sub>Lys</sub>.</p
Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens
Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae’s draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98–100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia ‘JpL’ genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88–90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.© The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
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Rec-DCM-Eigen: Reconstructing a Less Parsimonious but More Accurate Tree in Shorter Time
Maximum parsimony (MP) methods aim to reconstruct the phylogeny of extant species by finding the most parsimonious evolutionary scenario using the species' genome data. MP methods are considered to be accurate, but they are also computationally expensive especially for a large number of species. Several disk-covering methods (DCMs), which decompose the input species to multiple overlapping subgroups (or disks), have been proposed to solve the problem in a divide-and-conquer way
Combinatory cytotoxic effects produced by E1B-55kDa-deleted adenoviruses and chemotherapeutic agents are dependent on the agents in esophageal carcinoma
We examined possible combinatory antitumor effects of replication-competent type 5 adenoviruses (Ad) lacking E1B-55kDa molecules (Ad-delE1B55) and chemotherapeutic agents in nine human esophageal carcinoma cells. Ad-delE1B55 produced cytotoxic effects on all the carcinoma cells and the cytotoxicity is not directly linked with the p53 status of the tumors or with the infectivity to respective tumors. A combinatory treatment with Ad-delE1B55 and an anticancer agent, 5-fluorouracil (5-FU), mitomycin C or etoposide, produced greater cytotoxic effects than that with either the Ad or the agent. Administration of 5-FU could minimally inhibit the viral replication and a simultaneous treatment with the Ad and 5-FU achieved better cytotoxicity than sequential treatments. We also confirmed the antitumor effects by the combination of Ad-delE1B55 with 5-FU in vivo. Cisplatin, however, did not achieve the combinatory effects in most of the cells tested. These data indicate that the Ad-delE1B55 produce combinatory antitumor effects with a chemotherapeutic agent irrespective of the administration schedule, but the effects depend on an agent in esophageal carcinoma
The complete mitochondrial genome of Flustra foliacea (Ectoprocta, Cheilostomata) - compositional bias affects phylogenetic analyses of lophotrochozoan relationships
<p>Abstract</p> <p>Background</p> <p>The phylogenetic relationships of the lophophorate lineages, ectoprocts, brachiopods and phoronids, within Lophotrochozoa are still controversial. We sequenced an additional mitochondrial genome of the most species-rich lophophorate lineage, the ectoprocts. Although it is known that there are large differences in the nucleotide composition of mitochondrial sequences of different lineages as well as in the amino acid composition of the encoded proteins, this bias is often not considered in phylogenetic analyses. We applied several approaches for reducing compositional bias and saturation in the phylogenetic analyses of the mitochondrial sequences.</p> <p>Results</p> <p>The complete mitochondrial genome (16,089 bp) of <it>Flustra foliacea </it>(Ectoprocta, Gymnolaemata, Cheilostomata) was sequenced. All protein-encoding, rRNA and tRNA genes are transcribed from the same strand. <it>Flustra </it>shares long intergenic sequences with the cheilostomate ectoproct <it>Bugula</it>, which might be a synapomorphy of these taxa. Further synapomorphies might be the loss of the DHU arm of the tRNA L(UUR), the loss of the DHU arm of the tRNA S(UCN) and the unique anticodon sequence GAG of the tRNA L(CUN). The gene order of the mitochondrial genome of <it>Flustra </it>differs strongly from that of the other known ectoprocts. Phylogenetic analyses of mitochondrial nucleotide and amino acid data sets show that the lophophorate lineages are more closely related to trochozoan phyla than to deuterostomes or ecdysozoans confirming the Lophotrochozoa hypothesis. Furthermore, they support the monophyly of Cheilostomata and Ectoprocta. However, the relationships of the lophophorate lineages within Lophotrochozoa differ strongly depending on the data set and the used method. Different approaches for reducing heterogeneity in nucleotide and amino acid data sets and saturation did not result in a more robust resolution of lophotrochozoan relationships.</p> <p>Conclusion</p> <p>The contradictory and usually weakly supported phylogenetic reconstructions of the relationships among lophotrochozoan phyla based on mitochondrial sequences indicate that these alone do not contain enough information for a robust resolution of the relations of the lophotrochozoan phyla. The mitochondrial gene order is also not useful for inferring their phylogenetic relationships, because it is highly variable in ectoprocts, brachiopods and some other lophotrochozoan phyla. However, our study revealed several rare genomic changes like the evolution of long intergenic sequences and changes in the structure of tRNAs, which may be helpful for reconstructing ectoproct phylogeny.</p
Preclinical evaluation of transcriptional targeting strategies for carcinoma of the breast in a tissue slice model system
INTRODUCTION: In view of the limited success of available treatment modalities for metastatic breast cancer, alternative and complementary strategies need to be developed. Adenoviral vector mediated strategies for breast cancer gene therapy and virotherapy are a promising novel therapeutic platform for the treatment of breast cancer. However, the promiscuous tropism of adenoviruses (Ads) is a major concern. Employing tissue specific promoters (TSPs) to restrict transgene expression or viral replication is an effective way to increase specificity towards tumor tissues and to reduce adverse effects in non-target tissues such as the liver. In this regard, candidate breast cancer TSPs include promoters of the genes for the epithelial glycoprotein 2 (EGP-2), cyclooxygenase-2 (Cox-2), α-chemokine SDF-1 receptor (stromal-cell-derived factor, CXCR4), secretory leukoprotease inhibitor (SLPI) and survivin. METHODS: We employed E1-deleted Ads that express the reporter gene luciferase under the control of the promoters of interest. We evaluated this class of vectors in various established breast cancer cell lines, primary breast cancer cells and finally in the most stringent preclinical available substrate system, constituted by precision cut tissue slices of human breast cancer and liver. RESULTS: Overall, the CXCR4 promoter exhibited the highest luciferase activity in breast cancer cell lines, primary breast cancer cells and breast cancer tissue slices. Importantly, the CXCR4 promoter displayed a very low activity in human primary fibroblasts and human liver tissue slices. Interestingly, gene expression profiles correlated with the promoter activities both in breast cancer cell lines and primary breast cancer cells. CONCLUSION: These data suggest that the CXCR4 promoter has an ideal 'breast cancer-on/liver-off' profile, and could, therefore, be a powerful tool in Ad vector based gene therapy or virotherapy of the carcinoma of the breast
The creatine kinase pathway is a metabolic vulnerability in EVI1-positive acute myeloid leukemia
Expression of the MECOM (also known as EVI1) proto-oncogene is deregulated by chromosomal translocations in some cases of acute myeloid leukemia (AML) and is associated with poor clinical outcome. Here, through transcriptomic and metabolomic profiling of hematopoietic cells, we reveal that EVI1 overexpression alters cellular metabolism. A screen using pooled short hairpin RNAs (shRNAs) identified the ATP-buffering, mitochondrial creatine kinase CKMT1 as necessary for survival of EVI1-expressing cells in subjects with EVI1-positive AML. EVI1 promotes CKMT1 expression by repressing the myeloid differentiation regulator RUNX1. Suppression of arginine-creatine metabolism by CKMT1-directed shRNAs or by the small molecule cyclocreatine selectively decreased the viability, promoted the cell cycle arrest and apoptosis of human EVI1-positive cell lines, and prolonged survival in both orthotopic xenograft models and mouse models of primary AML. CKMT1 inhibition altered mitochondrial respiration and ATP production, an effect that was abrogated by phosphocreatine-mediated reactivation of the arginine-creatine pathway. Targeting CKMT1 is thus a promising therapeutic strategy for this EVI1-driven AML subtype that is highly resistant to current treatment regimens. Keywords: AML; RUNX1; CKMT1; cyclocreatine; arginine metabolismNational Cancer Institute (U.S.) (NIH 1R35 CA210030-01)Stand Up To CancerBridge ProjectNational Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. Grant P30-CA14051
Positive selection on panpulmonate mitogenomes provide new clues on adaptations to terrestrial life
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