Computational Methods for Efficient Processing and Analysis of Short-read Next-Generation DNA Sequencing Data

Computational Methods for Efficient Processing and Analysis of Short-read Next-Generation DNA Sequencing Data
Author: Praveen Nadukkalam Ravindran
Publisher:
Total Pages: 0
Release: 2020
Genre:
ISBN:

DNA sequencing has transformed the discipline of population genetics, which seeks to assess the level of genetic diversity within species or populations, and infer the geographic and temporal distributions between members of a population. Restriction-site associated DNA sequencing (RADSeq) is a NGS technique, which produce data that consists of relatively short (typically 50 to 300 nucleotide) fragments or "reads" of sequenced DNA and enables large-scale analysis of individuals and populations. In this thesis, we describe computational methods, which use graph-based structures to represent these short reads obtained and to capture the relationships among them. A key challenge in RADSeq analysis is to identify optimal parameter settings for assignment of reads to loci (singular: Locus), which correspond to specific regions in the genome. The parameter sweep is computationally intensive, as the entire analysis needs to be run for each parameter set. We propose a graph-based structure (RADProc), which provides persistence and eliminates redundancy to enable parameter sweeps. For 20 green crab samples and 32 different parameter sets, RADProc took only 2.5 hours while the widely used Stacks software took 78 hours. Another challenge is to identify paralogs, sequences that are highly similar due to recent duplication events, but occur in different regions of the genome and should not to be merged into the same locus. We introduce PMERGE, which identifies paralogs by clustering the catalog locus consensus sequences based on similarity. PMERGE is built on the fact that paralogs may be wrongly merged into a single locus in some but not all samples. PMERGE identified 62%-87% of paralogs in the Atlantic salmon and green crab datasets. Gene flow is the movement of alleles, specific sequence variants at a given locus, between populations and is an important indicator of population mixing that changes genetic diversity within the populations. We use the RADProc graph to infer gene flow among populations using allele frequency differences in exclusively shared alleles in each pair of populations. The method successfully inferred gene flow patterns in simulated datasets and provided insights into reasons for observed hybridization at two locations in a green crab dataset.

Computational Methods for Next Generation Sequencing Data Analysis

Computational Methods for Next Generation Sequencing Data Analysis
Author: Ion Mandoiu
Publisher: John Wiley & Sons
Total Pages: 460
Release: 2016-10-03
Genre: Computers
ISBN: 1118169484

Introduces readers to core algorithmic techniques for next-generation sequencing (NGS) data analysis and discusses a wide range of computational techniques and applications This book provides an in-depth survey of some of the recent developments in NGS and discusses mathematical and computational challenges in various application areas of NGS technologies. The 18 chapters featured in this book have been authored by bioinformatics experts and represent the latest work in leading labs actively contributing to the fast-growing field of NGS. The book is divided into four parts: Part I focuses on computing and experimental infrastructure for NGS analysis, including chapters on cloud computing, modular pipelines for metabolic pathway reconstruction, pooling strategies for massive viral sequencing, and high-fidelity sequencing protocols. Part II concentrates on analysis of DNA sequencing data, covering the classic scaffolding problem, detection of genomic variants, including insertions and deletions, and analysis of DNA methylation sequencing data. Part III is devoted to analysis of RNA-seq data. This part discusses algorithms and compares software tools for transcriptome assembly along with methods for detection of alternative splicing and tools for transcriptome quantification and differential expression analysis. Part IV explores computational tools for NGS applications in microbiomics, including a discussion on error correction of NGS reads from viral populations, methods for viral quasispecies reconstruction, and a survey of state-of-the-art methods and future trends in microbiome analysis. Computational Methods for Next Generation Sequencing Data Analysis: Reviews computational techniques such as new combinatorial optimization methods, data structures, high performance computing, machine learning, and inference algorithms Discusses the mathematical and computational challenges in NGS technologies Covers NGS error correction, de novo genome transcriptome assembly, variant detection from NGS reads, and more This text is a reference for biomedical professionals interested in expanding their knowledge of computational techniques for NGS data analysis. The book is also useful for graduate and post-graduate students in bioinformatics.

Computational Methods for the Analysis of Genomic Data and Biological Processes

Computational Methods for the Analysis of Genomic Data and Biological Processes
Author: Francisco A. Gómez Vela
Publisher: MDPI
Total Pages: 222
Release: 2021-02-05
Genre: Medical
ISBN: 3039437712

In recent decades, new technologies have made remarkable progress in helping to understand biological systems. Rapid advances in genomic profiling techniques such as microarrays or high-performance sequencing have brought new opportunities and challenges in the fields of computational biology and bioinformatics. Such genetic sequencing techniques allow large amounts of data to be produced, whose analysis and cross-integration could provide a complete view of organisms. As a result, it is necessary to develop new techniques and algorithms that carry out an analysis of these data with reliability and efficiency. This Special Issue collected the latest advances in the field of computational methods for the analysis of gene expression data, and, in particular, the modeling of biological processes. Here we present eleven works selected to be published in this Special Issue due to their interest, quality, and originality.

Computational Methods for Analyzing and Visualizing NGS Data

Computational Methods for Analyzing and Visualizing NGS Data
Author: Sruthi Chappidi
Publisher:
Total Pages:
Release: 2019
Genre: Application software
ISBN:

Advancements in next-generation sequencing (NGS) technology have enabled the rapid growth and availability of large quantities of DNA and RNA sequences. These sequences from both model and non-model organisms can now be acquired at a low cost. The sequencing of large amounts of genomic and proteomic data empowers scientific achievements, many of which were thought to be impossible, and novel biological applications have been developed to study their genetic contribution to human diseases and evolution. This is especially true for uncovering new insights from comparative genomics to the evolution of the disease. For example, NGS allows researchers to identify all changes between sequences in the sample set, which could be used in a clinical setting for things like early cancer detection. This dissertation describes a set of computational bioinformatic approaches that bridge the gap between the large-scale, high-throughput sequencing data that is available, and the lack of computational tools to make predictions for and assist in evolutionary studies. Specifically, I have focused on developing computational methods that enable analysis and visualization for three distinct research tasks. These tasks focus on NGS data and will range in scope from processed genomic data to raw sequencing data, to viral proteomic data. The first task focused on the visualization of two genomes and the changes required to transform from one sequence into the other, which mimics the evolutionary process that has occurred on these organisms. My contribution to this task is DCJVis. DCJVis is a visualization tool based on a linear-time algorithm that computes the distance between two genomes and visualizes the number and type of genomic operations necessary to transform one genome set into another. The second task focused on developing a software application and efficient algorithmic workflow for analyzing and comparing raw sequence reads of two samples without the need of a reference genome. Most sequence analysis pipelines start with aligning to a known reference. However, this is not an ideal approach as reference genomes are not available for all organisms and alignment inaccuracies can lead to biased results. I developed a reference-free sequence analysis computational tool, NoRef, using k-length substring (k-mer) analysis. I also proposed an efficient k-mer sorting algorithm that decreases execution time by 3-folds compared to traditional sorting methods. Finally, the NoRef workflow outputs the results in the raw sequence read format based on user-selected filters, that can be directly used for downstream analysis. The third task is focused on viral proteomic data analysis and answers the following questions: 1. How many viral genes originate as "stolen host" (human) genes? 2. What viruses most often steal genes from a host (human) and are specific to certain locations within the host? 3. Can we understand the function of the host (human) gene through a viral perspective? To address these questions, I took a computational approach starting with string sequence comparisons and localization prediction using machine learning models to create a comprehensive community data resource that will enable researchers to gain insights into viruses that affect human immunity and diseases.

Algorithms for Next-Generation Sequencing Data

Algorithms for Next-Generation Sequencing Data
Author: Mourad Elloumi
Publisher: Springer
Total Pages: 356
Release: 2017-09-18
Genre: Computers
ISBN: 3319598260

The 14 contributed chapters in this book survey the most recent developments in high-performance algorithms for NGS data, offering fundamental insights and technical information specifically on indexing, compression and storage; error correction; alignment; and assembly. The book will be of value to researchers, practitioners and students engaged with bioinformatics, computer science, mathematics, statistics and life sciences.

Algorithms for Next-Generation Sequencing

Algorithms for Next-Generation Sequencing
Author: Wing-Kin Sung
Publisher: CRC Press
Total Pages: 233
Release: 2017-05-18
Genre: Computers
ISBN: 1498752985

Advances in sequencing technology have allowed scientists to study the human genome in greater depth and on a larger scale than ever before – as many as hundreds of millions of short reads in the course of a few days. But what are the best ways to deal with this flood of data? Algorithms for Next-Generation Sequencing is an invaluable tool for students and researchers in bioinformatics and computational biology, biologists seeking to process and manage the data generated by next-generation sequencing, and as a textbook or a self-study resource. In addition to offering an in-depth description of the algorithms for processing sequencing data, it also presents useful case studies describing the applications of this technology.

Computational Methods for Next Generation Sequencing Data Analysis

Computational Methods for Next Generation Sequencing Data Analysis
Author: Ion Mandoiu
Publisher: John Wiley & Sons
Total Pages: 464
Release: 2016-09-12
Genre: Computers
ISBN: 1119272165

Introduces readers to core algorithmic techniques for next-generation sequencing (NGS) data analysis and discusses a wide range of computational techniques and applications This book provides an in-depth survey of some of the recent developments in NGS and discusses mathematical and computational challenges in various application areas of NGS technologies. The 18 chapters featured in this book have been authored by bioinformatics experts and represent the latest work in leading labs actively contributing to the fast-growing field of NGS. The book is divided into four parts: Part I focuses on computing and experimental infrastructure for NGS analysis, including chapters on cloud computing, modular pipelines for metabolic pathway reconstruction, pooling strategies for massive viral sequencing, and high-fidelity sequencing protocols. Part II concentrates on analysis of DNA sequencing data, covering the classic scaffolding problem, detection of genomic variants, including insertions and deletions, and analysis of DNA methylation sequencing data. Part III is devoted to analysis of RNA-seq data. This part discusses algorithms and compares software tools for transcriptome assembly along with methods for detection of alternative splicing and tools for transcriptome quantification and differential expression analysis. Part IV explores computational tools for NGS applications in microbiomics, including a discussion on error correction of NGS reads from viral populations, methods for viral quasispecies reconstruction, and a survey of state-of-the-art methods and future trends in microbiome analysis. Computational Methods for Next Generation Sequencing Data Analysis: Reviews computational techniques such as new combinatorial optimization methods, data structures, high performance computing, machine learning, and inference algorithms Discusses the mathematical and computational challenges in NGS technologies Covers NGS error correction, de novo genome transcriptome assembly, variant detection from NGS reads, and more This text is a reference for biomedical professionals interested in expanding their knowledge of computational techniques for NGS data analysis. The book is also useful for graduate and post-graduate students in bioinformatics.

Computational Methods for the Analysis of Genomic Data and Biological Processes

Computational Methods for the Analysis of Genomic Data and Biological Processes
Author: Francisco A. Gómez Vela
Publisher:
Total Pages: 222
Release: 2021
Genre:
ISBN: 9783039437726

In recent decades, new technologies have made remarkable progress in helping to understand biological systems. Rapid advances in genomic profiling techniques such as microarrays or high-performance sequencing have brought new opportunities and challenges in the fields of computational biology and bioinformatics. Such genetic sequencing techniques allow large amounts of data to be produced, whose analysis and cross-integration could provide a complete view of organisms. As a result, it is necessary to develop new techniques and algorithms that carry out an analysis of these data with reliability and efficiency. This Special Issue collected the latest advances in the field of computational methods for the analysis of gene expression data, and, in particular, the modeling of biological processes. Here we present eleven works selected to be published in this Special Issue due to their interest, quality, and originality.

Computational Methods for Analysis of Single Molecule Sequencing Data

Computational Methods for Analysis of Single Molecule Sequencing Data
Author: Ehsan Haghshenas
Publisher:
Total Pages: 127
Release: 2020
Genre:
ISBN:

Next-generation sequencing (NGS) technologies paved the way to a significant increase in the number of sequenced genomes, both prokaryotic and eukaryotic. This increase provided an opportunity for considerable advancement in genomics and precision medicine. Although NGS technologies have proven their power in many applications such as de novo genome assembly and variation discovery, computational analysis of the data they generate is still far from being perfect. The main limitation of NGS technologies is their short read length relative to the lengths of (common) genomic repeats. Today, newer sequencing technologies (known as single-molecule sequencing or SMS) such as Pacific Biosciences and Oxford Nanopore are producing significantly longer reads, making it theoretically possible to overcome the difficulties imposed by repeat regions. For instance, for the first time, a complete human chromosome was fully assembled using ultra-long reads generated by Oxford Nanopore. Unfortunately, long reads generated by SMS technologies are characterized by a high error rate, which prevents their direct utilization in many of the standard downstream analysis pipelines and poses new computational challenges. This motivates the development of new computational tools specifically designed for SMS long reads. In this thesis, we present three computational methods that are tailored for SMS long reads. First, we present lordFAST, a fast and sensitive tool for mapping noisy long reads to a reference genome. Mapping sequenced reads to their potential genomic origin is the first fundamental step for many computational biology tasks. As an example, in this thesis, we show the success of lordFAST to be employed in structural variation discovery. Next, we present the second tool, CoLoRMap, which tackles the high level of base-level errors in SMS long reads by providing a means to correct them using a complementary set of NGS short reads. This integrative use of SMS and NGS data is known as hybrid technique. Finally, we introduce HASLR, an ultra-fast hybrid assembler that uses reads generated by both technologies to efficiently generate accurate genome assemblies. We demonstrate that HASLR is not only the fastest assembler but also the one with the lowest number of misassemblies on all the samples compared to other tested assemblers. Furthermore, the generated assemblies in terms of contiguity and accuracy are on par with the other tools on most of the samples.

Biological Sequence Analysis

Biological Sequence Analysis
Author: Richard Durbin
Publisher: Cambridge University Press
Total Pages: 372
Release: 1998-04-23
Genre: Science
ISBN: 113945739X

Probabilistic models are becoming increasingly important in analysing the huge amount of data being produced by large-scale DNA-sequencing efforts such as the Human Genome Project. For example, hidden Markov models are used for analysing biological sequences, linguistic-grammar-based probabilistic models for identifying RNA secondary structure, and probabilistic evolutionary models for inferring phylogenies of sequences from different organisms. This book gives a unified, up-to-date and self-contained account, with a Bayesian slant, of such methods, and more generally to probabilistic methods of sequence analysis. Written by an interdisciplinary team of authors, it aims to be accessible to molecular biologists, computer scientists, and mathematicians with no formal knowledge of the other fields, and at the same time present the state-of-the-art in this new and highly important field.