International conference on bioinformatics of genome regulation
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Key words: DNA microarray, RNA-Seq, bioinformatics software Motivation and Aim: Bioinformatics analysis of gene expression molecular mechanisms has a great fundamental importance in various fields of science, particularly in medicine and statistics. Currently, there is a rapid development of genomic and biological technologies, which are leads to the accumulation of large experimental gene expression data in publicly available databases (most popular and free is BioGPS [1], GEO NCBI). Processing of such data requires development of new computer analysis methods, what will allow solve practical biomedical problems - reveal genes, associated with various diseases (cancer, neurodegenerative diseases and other). The purpose of this work is the creation of software for the analysis and visualization of transcriptomic and microarray data, which will be easy to use and multifunctional. Methods and Algorithms: The Affymetrix GeneChip U133A data on the human genome and genomes of model organisms (mice and rats) were used as test data. The program is written in Python language using JSON modules, and also popular libraries for processing and visualization text and numerical data (pandas, numpy, scipy, matplotlib). Results: Software package ExpGene has been developed. It includes a set of options to work with a large array of microarray data - preprocessing, statistical analysis of gene expression correlations and visualization. This tool is also designed to work with gene ontologies. It allows search genes in the chromosome loops formed by pairs of CTCF transcription factor binding sites. It is versatile for any type of text databases (allows the user to pre-select processed data). The program has a user-interaction interface (menu) and is easy to handle even by an inexperienced user. Conclusion: Using this program we performed a comparative analysis of different samples of genes [1], such as genes from gene networks annotated in the ICG SB RAS regulating cholesterol levels and circadian rhythm. We also studied genes, which are responsible for aggressive behavior of laboratory animals (rats). Gene expression correlation matrices for gene lists were reconstructed as basis for qualitative analysis of the gene network studied. Availability: Software is available from the author upon request. References: 1. A.M. Spitsina et al. (2015) Supercomputer analysis of genomics and transcriptomics data revealed by high-throughput DNA sequencing, Program systems: theory and applications, 6:1(23): 157–174. (In Russian) 295 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY PREDICTING SMALL RNAS FROM BACTERIAL GENOME T. Stankovic*, J. Guzina, M. Nikolic, M. Djordjevic 1 Faculty of Biology, University of Belgrade, Serbia * Corresponding author: tamara.stankovic@bio.bg.ac.rs Key words: CRISPR/Cas, small RNAs, transcription start site predictions, terminator predictions Motivation and Aim: Small RNAs perform important regulatory roles in bacteria. Their discovery is however complicated by still limited availability of dRNA-seq data in bac- teria, and by the fact that they are often expressed under non-standard and poorly charac- terized conditions, which may not correspond to those of the experiment. Furthermore, small RNAs are often poorly cфonserved even between related bacterial strains, which complicate their computational discovery. As an alternative, small RNAs can be detected directly from the genome sequence, which requires accurately predicting transcription start site (TSS) and terminator signals. However, two main limiting factors in this ap- proach are generally insufficient accuracy with which TSS are predicted in genome, and the fact that the terminator prediction parameters are trained on E. coli data, which may lead to suboptimal predictions in other bacteria. The aim of this work is improving TSS predictions, and assessing if the parameters for terminator predictions can be retrained to allow accurately predicting a specific group of small RNAs. Methods: For TSS predictions, we start from accurate alignments of the promoter ele- ments for sD.S. Johnson et al. (2008) Systematic evaluation of variability in ChIP-chip experiments using predefined DNA targets, Genome Res. 18: 393-403. Z.D. Zhang et al., Modeling ChIP Sequencing In Silico with Applications, PLoS Com- putational Biology (2008), 4: 1-10. 296 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY IDENTIFICATION OF BACILLUS PUMILUS GROUP STRAINS BY MALDI TOF MS USING GEOMETRIC APPROACH K.V. Starostin, E.A. Demidov, A.V. Bryanskaya, V.M. Efimov, A.S. Rozanov, S.E. Peltek Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia Key words: microbiology, mass spectrometry Geometric approach is based on representing mass spectra as points on a multidimen- sional space, which allows us to use geometric distances to compare the spectra. The aim of this study was to test if the geometric approach could be used to identify closely related species. As a model for testing this approach, we used 24 closely related strains of the B. pumilus group from the collection of the Institute of Cytology and Genetics SB RAS, which had over 98% sequence similarity for the 16S rRNA gene. The studied strains were isolated from various extreme habitats in various regions of Russia, including thermal springs, saline lakes, complex ore deposits, etc. 16S rRNA sequences were used to validate the results of mass spectrometry analysis. Two groups referred to as the A and P groups were detected in our dataset with the bootstrap support of 96. The A group included strains isolated from Kamchatka thermal springs, rhizosphere of higher plants from the Novosibirsk oblast, as well as the B. al- titudinis type strain (AJ831842). The P group contained strains from saline lakes of the Novosibirsk oblast, complex ore deposits of the Kemerovo oblast, and type strains of B. pumilus (AY456263) and B. safensis (AB681259). The mass spectra centroids of the studied strains were separated into two groups, which was confirmed by the Welsh’s t-test. These groups correspond to the two clusters de- tected on the phylogenetic tree. The dendrogram constructed by the Ward method using all 23 coordinates also yields similar results. We performed an additional analysis of mass-spectrometry data using Biotyper 3.0 as an extra check. All three methods used allowed us to reliably distinguish between two groups that correspond to two species, B. pumilus (P) and B. altitudinus (A). The obtained reference database was used for identification of the studied microorgan- isms by wet-lab experiments. Identification accuracy was 98% for Jaccard coefficients and 100% for Euclidean distances. 297 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY CHANGES IN THE BRAIN TRANSCRIPTOME OF OXYS RATS AS THE SIGNS OF ALZHEIMER’S DISEASE DEVELOP AND EFFECTS OF SKQ1 N.A. Stefanova*, N.I. Ershov, N.A. Muraleva, N.G. Kolosova Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia * Corresponding author: stefanovan@mail.ru Key words: Alzheimer’s disease, RNA-Seq, senescence-accelerated OXYS rats Motivation and Aim: Alzheimer’s disease (AD) is a progressive, age-dependent neurode- generative disorder, featuring progressive impairments in memory, cognition, and ultimate- ly leads to death. In this study, using nontransgenic OXYS rats that simulate key aspects of sporadic AD, we aimed to compare the gene expression profiles of the prefrontal cortex from OXYS rats and Wistar rats (as control) to identify the molecular mechanisms and the factors underlying disease progression. The transcriptome analysis was conducted at three stages of the disease (pre-symptomatic, symptomatic and progressive stage) in OXYS rats, using RNA-Seq technique. In addition, we set out to determine a role of mitochondria in the disease pathology. OXYS rats were treated with specifically target mitochondria antioxidant SkQ1 from age 12 to 18 months, that is, during active progression of AD-like pathology in these animals. Results: The development of the signs of AD in OXYS rats takes place during changes in mRNA expression of the genes that are mostly related to neuronal plasticity, calcium ho- meostasis, hypoxia, mitochondrial dysfunction, immune processes, and apoptosis. Between ages 20 days and 5 months, that is, during active changes in cognition, > 5,000 genes under- go changes in expression in both rat strains. In OXYS rats, with age, >5,500 genes change their expression, whereas in Wistar rats, only 499 genes show changes. Most of these genes have something to do with phosphorylation, neurogenesis, synaptic plasticity, and the im- mune system. The similarity of the mechanisms of accelerated aging of the OXYS rats’ brain with the pathogenesis of this disease formed the basis for comparative analysis of transcriptomic alterations in the cortex in human AD and in OXYS rats. We found that changes in the expression of 219 genes are shared between AD patients and OXYS rats; these genes are mostly related to mitochondrial dysfunction, synaptic plasticity, and the calcium signaling pathway. We next studied the hippocampal transcriptome of 18-month- old OXYS and Wistar rats and of OXYS rats treated with SkQ1 from age 12 to 18 months, that is, during active progression of AD-like pathology in these animals. In the RNA-Seq results, SkQ1 decreased differential expression of genes in the hippocampus of OXYS rats; these effects of the drug may have something to do with improved mitochondrial function and normalization of a wide range of cellular signaling processes. This notion is supported by the results of evaluation of SkQ1’s effects on progression of the key signs of Alzheimer’s disease in OXYS rats: treatment with SkQ1 significantly improved mitochondrial and syn- aptic deficits, prevented neuronal loss and retarded structural neurodegenerative alterations, decreased amyloid β levels, and attenuated the memory deficits. Conclusion: Thus, we obtained convincing evidence that the OXYS strain of rats matches the main criteria of the sporadic form of AD and holds promise for research into the etiology and pathogenesis of this disease and for studies on therapeutic and prophylactic interven- tions. This work was supported by grants from the Russian Foundation for Basic Research (projects ## 15-04-01938 and 15-04-06066) 298 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY ULTRASTRUCTURAL ANALYSIS OF MITOTIC DIVISION IN DROSOPHILA S2 CELLS A.A. Strunov 1, 2 *, L.V. Boldyreva 2 , A.V. Pindyurin 2 , M. Gatti 2, 3 , E. Kiseleva 1 1 Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia 2 Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russia 3 Sapienza University of Rome, Rome, Italy *Corresponding author: strunov.anton@gmail.com Key words: TEM mitosis microtubules S2 cells k-fibers Drosophila Motivation and Aim: Drosophila S2 cells are a well-known system for the analysis of mitosis. These tissue culture cells have been used to conduct several RNA interference- based genome-wide screens aimed at the identification of mitotic genes. However, very few data are currently available on the ultrastructure of dividing S2 cells. Since it is virtually impossible to synchronize insect cells, obtaining S2 cells mitoses for TEM analysis is a long and difficult process. We thus developed a new approach for collecting dividing S2 cells for TEM analysis, which allowed us to obtain novel information on the organization of spindle microtubules (MTs). Methods and Algorithms: We used asynchronously growing Drosophila S2 cells, which were pelleted by centrifugation, fixed and sectioned for TEM. Sections were examined for MT organization at different stages of mitosis. Results: We found that MT organization is highly dynamic during mitosis. MTs most- ly appear as single elements in early prometaphase; they then form bundles (generally containing 8-30 MTs) in late prometaphase and metaphase; these bundles interact with the kinetochores either on an end-on fashion (k-fibers) or laterally (lateral bundles). In anaphase, the MT bundles become irregular and the spaces between MTs are filled with proteinaceous material. In telophase, MTs converge to form a midbody, a large MT bun- dle that mediates cytokinesis. Conclusion: Our data provide detailed information of microtubule organization during mitosis of Drosophila S2 cells and reveal that during late prometaphase and metaphase MTs form bundles that are end-on or laterally attached to kinetochores. A similar MT organization has not been observed in mammalian cells. Acknowledgements: This study was supported by the grant from the Ministry of Educa- tion and Science of Russian Federation no. 14.Z50.31.0005. 299 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY ULTRASTRUCTURAL ANALYSIS OF SPINDLE AND KINETOCHORES IN AUGMIN-DEPLETED DROSOPHILA S2 CELLS A.A. Strunov 1, 2 *, L.V. Boldyreva 2 , A.V. Pindyurin 2 , M. Gatti 2, 3 , E. Kiseleva 1 1 Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia 2 Institute of Molecular and Cellular Biology, Novosibirsk, Russia 3 Sapienza University of Rome, Rome, Italy * Corresponding author: strunov.anton@gmail.com Key words: mitosis microtubules Dgt6 RNAi spindle ultrastructure Motivation and Aim: Spindle formation in S2 cells exploits microtubules (MTs) nucle- ated by the centrosomes, MTs that grow from the kinetochores, and MTs nucleated by γ-tubulin ring complexes (γ-TuRC) associated with the lateral walls of preexisting MTs. γ-TuRC association with MTs is mediated by the augmin complex, which interact with kinetochore proteins and is primarily required for kinetochore driven MT growth. RNA interference-mediated augmin depletion results in defective kinetochore fibers, meta- phase arrest, and in many cells with ana-telophase spindles that contain chromosomes with joined sister chromatids. These peculiar mitotic figures, we call pseudo ana-telo- phases (PATs), exhibit high Cyclin B levels and are therefore metabolically in meta- phase. To further define the mitotic role of augmin we analyzed the spindle ultrastructure in augmin-depleted S2 cells. Methods and Algorithms: We performed RNA interference (RNAi) in S2 cells against the Dgt6 gene that encodes a component of the augmin complex. Cells were treated for 5 days with Dgt6 double-stranded RNA, fixed and sectioned for TEM analysis. Results: TEM showed that in Dgt6 RNAi cells the MT bundles associated with kine- tochores, either end-on or laterally, are thinner than in controls and sometimes slightly curved, a phenotype never observed in control cells. We also observed several PATs with an elongated shape and the chromosomes at the center of the cell. The kinetochores of these cells often showed a poorly defined and extended structure. In addition, some of the chromosomes at the center of the PATs were partially coated with a double mem- brane just like the telophase chromosomes of control cells undergoing nuclear envelope reassembly. Conclusion: Our TEM analyses uncover new details of the mitotic phenotype of Dgt6- depleted cells and characterize the PATs at the ultrastructural level. Acknowledgements: This study was supported by the grant from the Ministry of Educa- tion and Science of Russian Federation no. 14.Z50.31.0005. 300 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY MYC GENE FAMILY IN CEREALS: TRANSFORMATION IN THE COURCE OF THE TRITICUM AND AEGILOPS GENERA EVOLUTION K.V. Strygina 1 *, E.K. Khlestkina 1, 2 1 Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia 2 Novosibirsk State University, Novosibirsk, Russia * Corresponding author: pushpandzhali@bionet.nsc.ru Keywords: Aegilops, bHLH, gene divergence, gene duplication, flavonoids biosynthesis, MYC, Triticum, transcription factor Motivation and Aim: MYC family transcription factors are of an essential part of the regulatory complex «MYB + MYC + WD40», which is necessary for gene activation in flavonoid biosynthesis. In bread wheat (Triticum aestivum L., BBAADD, 2n=6x=42) the gene TaMyc1 controlling the synthesis of flavonoid pigments in wheat seed was earlier isolated and characterized [1]. The aim of the current study was to identify, characterize and compare full-length sequences of duplicated homoeologous and paralogous copies of the TaMyc1 gene. Methods and Algorithms: The search of homologous sequences was made in databases for not annotated wheat sequences using BLAST. The cluster analysis using the MEGA software was based on UPGMA algorithm. The nucleotide substitutions rate (k) for Myc was calculated by the formula Ks/2T. The obtained value (k=10.04×10 9 ) was used for the calculation of divergence time of duplicated copies. Results and discussion: We identified 10 copies of the gene TaMyc1 in a common wheat genome and 22 Myc–like genes in the genomes of related species (T.durum; T.urartu, T.monococcum, Aegilops speltoides, Ae.sharonensis, Ae.tauschii). Analysis of genetic similarity showed that the first duplication of Myc gene was in the diploid common ancestor of the tribe Triticeae. The duplication has undergone from two to four further acts of duplication in Triticum and Aegilops genomes. Time of occurrence of each new copy is calculated and presented in the report. Maintaining functional duplicated genes is likely due to their specialization. It is assumed that TaMyc1 copies may be involved in the synthesis of various flavonoid compounds in different parts of the plant. Conclusion: Polyploid genome of bread wheat carries at least 11 copies of the TaMyc gene involved in flavonoid biosynthesis regulation. The duplications of this gene occurred several times in the course of evolution of diploid wheat progenitors. The exon-intron organization of these genes is the same to the TaMyc1 structure. All available sequences have a conserved bHLH domain. None significant change in the motive, which could lead to changes in gene function, has been identified among the annotated Myc genes of T. aestivum and related species. Acknowledgements: This study was partially supported by the RAS MCB Programme (0324-2015-0016) and by RFBR (16-04-00912). References: 1. Shoeva, O. Y., Gordeeva, E. I., Khlestkina, E. K. 2014. The regulation of anthocyanin synthesis in the wheat pericarp. Molecules, 19(12), 20266-20279. 301 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY IN SILICO MODELLING OF EXPERIMENTAL CHIP-SEQ PROCESS T. Subkhankulova*, F.M. Naumenko 2 , Y.L. Orlov 1 Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK 2 Novosibirsk State University, Novosibirsk Rissia * Corresponding author: subkhankul@hotmail.com Key words: transcription factor binding sites, modeling, ChIP-seq Chromatin immunoprecipitation followed by next generation sequencing (ChIP-Seq) is rec- ognised as an extremely power tool for study of protein–DNA interactions at a genome- wide scale. Identifying gene regulatory elements and the epigenetic modifications is crucial for reconstruction of the dynamic interplay between the epigenome and gene regulatory networks. ChIP-Seq technique is based on isolation of protein–DNA complexes followed by massively parallel DNA sequencing. Output ChIP-Seq data are analysed using a number of computational steps including alignment of reads to genome and peak calling analysis. Currently, more than a hundred of mapping and peak calling software together are devel- oped. There is a high inconsistency between the results produced by different analysing programs. Therefore, the choice of appropriate software to achieve the highest standard in ChIP-Seq analysis becomes an immensely challenging task as well as optimisation of ChIP- Seq experimental conditions such as chromatin shearing, chromatin precipitation steps, the amounts of cells taken for analysis, pre-amplification of sheared chromatin, etc. The effi- ciency and precision of ChIP are typically assessed using spike controls or limited number of positive/negative loci followed by RT-PCR analysis, or using more advanced techniques, e.g. by placing tags onto the genome according to particular assumed distributions for the actual binding site. However, little consideration has been given to in silico modelling of whole pro- cess of ChIP-Seq with controlled parameters of the process and a priori known input. Here, we developed unique software, isChIP, capable to fully model ChIP-Seq data in silico. As input files for isCHIP we have been using a bed-files generated from “true” biding sites well known for transcription factors or assumed to be true for the modelling purposes. We validated isChIP, demonstrating that it closely approximates real ChIP-Seq experiment: (i) location of simulated peaks coincides with experimental enriched peaks, (ii) the shape and density of the model peaks resemble the real peaks, and (iii) modelled input files represent unspecific background similar to experimental input data. Using isChIP we have briefly compared two different mapping programs (Bowtie and BWA), and in more details a few peak calling software (CCAT, MAСS, PeakRanger, Qeseq). Our analysis revealed that the tested mapping programs are prone to some byes in alignment of reads to the indexed genome. Analysis of four programs showed that the peak calling algorithm was much more essential in localization of “true” peaks rather than parameters adjusted in each program. IsChIP is applicable for other tasks such as estimation of optimal DNA shearing size, minimal cell number sufficient for successful ChIP-Seq experiment in given conditions, necessity and levels of pre-amplification prior the library construction. Finally, developed in silico modelling approach may serve as cost and time effective ChIP- Seq optimization. References: 1. D.S. Johnson et al. (2008) Systematic evaluation of variability in ChIP-chip experiments using prede- fined DNA targets, Genome Res. 18: 393-403. 2. Z.D. Zhang et al., Modeling ChIP Sequencing In Silico with Applications, PLoS Computational Biol- ogy (2008), 4: 1-10. 302 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY SINGLE CELL EXPRESSION PROFILING OF NEURAL CREST-DERIVED CELLS T. Subkhankulova 1 , G. Aquino 2 , A. Rocco 2 , H. Schwetlick 1 , R.N. Kelsh 1 1 Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK 2 Department of Microbial and Cellular Sciences, University of Surrey, Guildford GU2 7XH, UK * Corresponding author: ts723@bath.ac.uk Download 3.91 Kb. Do'stlaringiz bilan baham: |
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