BOL: Rahul Nayak's bookmarks

RGFA: powerful and convenient handling of assembly graphs

Rahul Nayak — Thu, 25 Jan 2018 05:47:53 -0600

RGFA, an implementation of the proposed GFA specification in Ruby. It allows the user to conveniently parse, edit and write GFA files. Complex operations such as the separation of the implicit instances of repeats and the merging of linear paths can be performed. A typical application of RGFA is the editing of a graph, to finish the assembly of a sequence, using information not available to the assembler. We illustrate a use case, in which the assembly of a repetitive metagenomic fosmid insert was completed using a script based on RGFA.

https://github.com/ggonnella/rgfa

Address of the bookmark: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5103826/

HTTDB - Horizontally transferred transposable elements database

Rahul Nayak — Tue, 23 Jan 2018 12:07:31 -0600

Transposons or Transposable elements (TEs) are "mobile genes" capable of mobilization from one genomic location to another through non-homologous recombination. As this movement is mediated by its own proteins and does not contribute to the survival of the host that it inhabits, they are known as selfish genomic parasites. Despite their capacity for transposition inside genomes, they can frequently transpose the species boundaries and consequently migrate from one species to another. Such phenomenon is called Horizontal Transposons Transfer. HTT was first discovered by Daniels et al. (1984) when analysing a P element that was transferred from Drosophila willistoni to D. melanogaster. Since then, many more cases have been documented in the literature. Moreover, in the last years, such discoveries have been boosted by the unprecedented amount of new genomes available. Despite the recognition of HTT as a common phenomenon in recent years, it is still difficult to draw major conclusions about HTT patterns, such as where in the tree of life these cases are more frequently found. This is mainly due to the historical bias and lack of studies in many taxa. To date, there has been no easy way to visualise each TE or host species, and should be further analysed in order to provide a more comprehensive view of such phenomena. Based on these concerns, we developed the HTT database to keep an updated repository of HTT events in all eukaryotes, allowing not only TE specialists to add new events and search the database, but also non-specialists. Moreover, we expanded the database to include Horizontal-Virus Transfer also known as endogenization events which is characterized by the stable integration a viral genomic fragment into the host genome.

https://www.ncbi.nlm.nih.gov/pubmed/29315358

Address of the bookmark: http://lpa.saogabriel.unipampa.edu.br:8080/httdatabase/

PGAP-X: Extension on pan-genome analysis pipeline

Rahul Nayak — Tue, 23 Jan 2018 11:41:43 -0600

PGAP-X is a microbial comparative genomic analysis platform with graphic interface. Serials of algorithms and methodologies have been developed and integrated to analyze and visualize genomics structure variation, gene distribution with different conservative levels, and genetic variation from pan-genome sight. At the same time, analytical result data from many other programs, including genome alignment result and orthologs clusters, are also supported to be further analyzed or visualized in PGAP-X. The workflow and feature snapshot in PGAP-X were shown as Fig.1 and Fig.2.

Address of the bookmark: https://pgapx.ybzhao.com/

Rectangle Graph for Repeat Resolution in Genome Assembly

Rahul Nayak — Thu, 28 Dec 2017 09:43:03 -0600

Ultimate tool for resolving repeats in genome assemblies.

Though the specific implementation of the idea of the rectangle graph approach is already included into the current SPAdes distribution, we're also releasing the Rectangle Graph Module (RGM) as the separate code which can be run independently of SPAdes. Although RGM differs from the current implementation of the rectangle graph approach in SPAdes, in the future we plan to integrate RGM in SPAdes. RGM can be run with other genome assemblers if they use the graph format as SPAdes files.

For more details see: Nikolay Vyahhi, Son K. Pham, Pavel Pevzner. From de Bruijn Graphs to Rectangle Graphs for Genome Assembly, Lecture Notes in Bioinformatics 7534 (2012), pp. 249-261.

Address of the bookmark: http://bioinf.spbau.ru/en/rectangles

CAMSA :: a tool for Comparative Analysis and Merging of Scaffold Assemblies

Rahul Nayak — Thu, 28 Dec 2017 09:10:26 -0600

CAMSA – is a tool for Comparative Analysis and Merging of Scaffold Assemblies, distributed both as a standalone software package and as Python library under the MIT license.

Main features:

works with any number of scaffold assemblies in de-novo non-progressive fashion
allows to simultaneously work with scaffold assemblies obtained from any in silico and in vitro techniques, supporting multiple existing formats via built-in converters
creates an extensive report with several comparative quality metrics (both on assembly level and on the level of individual assembly points)
constructs a merged combined scaffold assembly
provides an interactive framework for a visual comparative analysis of the given assemblies

Address of the bookmark: https://cblab.org/camsa/

xmatchview: smith-waterman alignment visualization

Rahul Nayak — Thu, 28 Dec 2017 09:00:58 -0600

xmatchview and xmatchview-conifer are imaging tools for comparing the synteny between DNA sequences. It allows users to align 2 DNA sequences in fasta format using cross_match and displays the alignment in a variety of image formats. xmatchview and xmatchview-conifer are written in python and run on linux and windows. They serve as visual tools for analyzing cross_match alignments. Cross_match (Green, P. (1994) http://www.phrap.org) uses an implementation of the Smith-Waterman algorithm for comparing DNA sequences that is sensitive.

http://www.bcgsc.ca/platform/bioinfo/software/xmatchview

Address of the bookmark: https://github.com/warrenlr/xmatchview

R googleVis examples

Rahul Nayak — Sun, 10 Dec 2017 06:13:42 -0600

It may take a little while to load all charts. Please be patient. All charts require an Internet connection.

These examples are taken from the googleVis demo. You can execute the demo via

library(googleVis)
demo(googleVis)

For more details about the charts and further examples see the helpfiles of the individual googleVis function and review the Google Charts API documentation and Terms of Service.

Address of the bookmark: https://cran.r-project.org/web/packages/googleVis/vignettes/googleVis_examples.html

dnaPipeTE: de-novo assembly & annotation Pipeline for Transposable Elements

Rahul Nayak — Sat, 02 Dec 2017 18:25:44 -0600

dnaPipeTE (for de-novo assembly & annotation Pipeline for Transposable Elements), is a pipeline designed to find, annotate and quantify Transposable Elements in small samples of NGS datasets. It is very useful to quantify the proportion of TEs in newly sequenced genomes since it does not require genome assembly and works on small datasets (< 1X).

dnaPipeTE is developped by Clément Goubert, Laurent Modolo and the TREEP team of the LBBE: http://lbbe.univ-lyon1.fr/-Equipe-Elements-transposables-.html?lang=en
You can find the original publication in GBE here: https://academic.oup.com/gbe/article/7/4/1192/533768

output examples of quantification and TE landscape (relative age) produced by dnaPipeTE

Address of the bookmark: https://github.com/clemgoub/dnaPipeTE

Automatic Filtering, Trimming, Error Removing and Quality Control for fastq data

Rahul Nayak — Mon, 13 Nov 2017 05:10:23 -0600

Automatic Filtering, Trimming, Error Removing and Quality Control for fastq data
AfterQC can simply go through all fastq files in a folder and then output three folders: good, bad and QC folders, which contains good reads, bad reads and the QC results of each fastq file/pair.
Currently it supports processing data from HiSeq 2000/2500/3000/4000, Nextseq 500/550, MiniSeq...and other Illumina 1.8 or newer formats

Address of the bookmark: https://github.com/OpenGene/AfterQC

R tuorial

Rahul Nayak — Mon, 31 Jul 2017 08:41:40 -0500

R learning resources

https://flowingdata.com/

Address of the bookmark: https://flowingdata.com/