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Bipartite graphs for microbiome analysis
Šafárová, Marcela ; Provazník, Ivo (referee) ; Sedlář, Karel (advisor)
Microorganisms are all around us. Some of them even live in our body and are essential for our healthy being. Study of microbial communities based on their genetic content has become very popular with the development of new technologies, which enable easy reading of DNA or RNA. The key role of these studies is usually to characterize significant microbial patterns of an environment. However, currently used visualization tools have many drawbacks for such analyses. The subject of this thesis is to design a R/Bioconductor package for simple creation of bipartite graphs from microbial data. This type of visualization brings many advantages for microbiome analysis. Benefits of bipartite graphs are further demonstrated by analysis of main parameters affecting computer processing of microbial data.
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Functional annotation of non-model bacteria based on sequential homology
Polakovičová, Petra ; Musilová, Jana (referee) ; Sedlář, Karel (advisor)
Genomová sekvence je důležitým zdrojem informací v oblasti biologie, a proto je neustálým předmětem zájmu vědeckého výzkumu. Na práci s genomem a jeho analýzu nabízí bioinformatika různé výpočetní metody. Tato práce se věnuje bakteriálnímu genomu, jeho organizaci, základním vlastnostem a následně popisuje jeho anotaci. Zaměřuje se hlavně na funkční anotaci (popis biologické funkce predikovaných genů) na základě přiřazení takzvaných klastrů ortologních genů (COG) s využitím sekvenční homologie. Popisuje nejpoužívanější nástroje a databáze, které se využívají pro COG anotaci a poté několik z nich porovnává při anotaci sedmi bakteriálních genomů. Jejím hlavním cílem je navrhnout metodu, která vylepší COG anotaci a zjednoduší její výslednou vizualizaci.
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Direct assembly of genome signals from nanopore sequencing
Karmazinová, Inna ; Maděránková, Denisa (referee) ; Sedlář, Karel (advisor)
The aim of this bachelor thesis is to search for overlaps between signals from nanopore sequencing using MinION device version R9. The theoretical part deals with methods used for genome assembly - greedy algorithm, overlap-layout-consensus (OLC) and de Bruijn graphs. Oxford Nanopore Technologies introduced the MinION device, which simplifies sequencing using the current change, which occurs while the DNA is passing through the nanopore. The error rate of the device is still high, the accuracy problem occurs during the base-calling. Using the difference signal, possibly also the dynamic time warping, it is possible to find overlaps between the individual signals. Signal analysis and genome assembly using the MinION signal could provide better accuracy.
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Whole genome alignment using suffix trees
Klouba, Lukáš ; Sedlář, Karel (referee) ; Maděránková, Denisa (advisor)
The aim of this thesis is to create an algorithm that allows the alignment of the genome of two organisms by means of suffix structures and to implement it into the programming language environment R. The thesis deals with the description of the construction of the suffix structures and the methods of whole genome alignment. The result of the thesis is a functional algorithm for whole genome alignment by means of suffix structures implemented in the software environment R and its comparison with similar programs for the whole genome alignment.
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Influence of second and third generation sequencers on cgMLST analysis of closely-related bacterial strains.
Slavíček, David ; Sedlář, Karel (referee) ; Nykrýnová, Markéta (advisor)
This bachelor thesis is about influence of sequncers of second and third generationon cgMLST analysis of bacterial genome. In the theoretical section were described selected sequencers of second and third generation and genome assembly principles. In the practical part were assembled six genomes of Klebsiella pneumoniae bacteria from University Hospital Brno. The genomes were sequenced each on two different sequencers, Illumina Miseq and Oxford Nanopore Technologies Minion. The genomes were assembled. Suitable genes were selected and insufficient quality genomes removed for the cgMLST analysis. The cgMLST analysis was performed and the results are shownin graphs.
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Methods of DNA tandem repeats analysis
Havlík, Kryštof ; Sedlář, Karel (referee) ; Maděránková, Denisa (advisor)
This work clarifies basics of the repetitive DNA and evaluates thee tandem repeats finders, which are accessible to public free of payment. Second part describes an algorithm used for searching tandem repeats, based on converting DNA string into numerical signal. Then follows signal processing using short-time Fourier transform, formation of spectrogram and analysis for evaluating position and content of repetitive areas. Result of this work is comparison of outcomes provided by public accessible programs with results of created program and review of advantages and disadvantages.
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Gene order conservation in bacterial genomes
Martinková, Tereza ; Sedlář, Karel (referee) ; Maděránková, Denisa (advisor)
Theoretical part of the thesis deals with basic concepts such as bacterial genome, comparative genomics and mainly synteny blocks. Here is explained what synteny is and what is its importance. In the theoretical part, the GenBank format is also mentioned, its content and usage. The practical part is focused on searching similarities in DNA sequences of reference bacteria with selected bacteria, their sorting by means of greedy algorithm and visualization of similarities using phylogenetic tree.
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Processing of Unique Molecular Identifiers without Mapping to a Reference Genome
Barilíková, Lujza ; Demko, Martin (referee) ; Sedlář, Karel (advisor)
Hlavným cieľom tejto práce je návrh nového algoritmu k spracovaniu unikátnych molekulárnych indexov bez mapovania na referenčný genóm. O tieto náhodné oligonukleotidové sekvencie neustále vzrastá záujem, pretože uľahčujú rozpoznávať PCR chyby a skresľovanie údajov. Keďže používanie technológií sekvenovania novej generácie neustále rastie, je vynaložené veľké úsilie vyvíjať nástroje pre analýzu produkovaných dát. V súčasnosti sú nástroje na riešenie týchto chýb relatívne časovo náročné a zložité z dôvodu výpočtovo náročného zarovnania. Najdôležitejšie obmedzenie týchto nástrojov spočíva v skutočnosti, že pri spracovávaní duplikátov sú povolené multi-mapované čítania. Tieto čítania sú zvyčajne ignorované, čo môže viesť k zníženiu kvantitatívnej presnosti a spôsobiť zavádzajúcu interpretáciu výsledkov daného sekvenovania. V snahe vyriešiť tento problém je v tejto práci uvedený nový prístup, ktorý umožňuje odhad absolútneho počtu jedinečných molekúl s relatívne rýchlym a spoľahlivým spôsobom.
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Comparative and phylogenetic analysis of viruses in the University Hospital Brno
Švestková, Tereza ; Sedlář, Karel (referee) ; Nykrýnová, Markéta (advisor)
This thesis is focused on the SARs-CoV-2 coronavirus associated with severe acute respiratory syndrome, which was first identified in 2019. This coronavirus caused a pandemic that affected almost the entire world. Knowledge of the genetic information is needed for vaccine development, to determine infectivity and to predict the evolution of SARs-CoV-2 variants. To obtain genetic information, RNA must be sequenced and these genomic sequences must be assembled. By comparing the assembled genomes, it is possible to find out which part of the organism has mutated. Phylogenetic analysis is performed on the basis of the concordance or divergence in the assembled genomes, which indicates the evolution of the organism and shows the evolutionary relationship with other organisms. The practical part is focused on the assembly of genomes from samples from patients in the University Hospital Brno and evaluation of the quality of the assembly. After the genomes are assembled, the next goal is to evaluate the variability and subsequent phylogenetic analysis.
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Prediction of the replication origin in prokaryotic genomes
Lebó, Marko ; Maděránková, Denisa (referee) ; Sedlář, Karel (advisor)
This bachelor’s thesis deals with the problem of origin of replication (oriC) detection in genomes of prokaryotic organisms. It describes the differences in the processes of initiation of replication in organism of the both procaryotic domains – Bacteria and Archea. It describes the possibilities of conversion of DNA sequences into their numeric representaions and evaluates their application for oriC detection. Also, it describes different approaches in oriC detection and describes te functioning of already present programmes for oriC detection. Finally, it suggests a new tool for oriC detection in bacterial genomes – FindOri and discusses results, achieved during the testing of this tool.
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