<?xml version='1.0'?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:georss="http://www.georss.org/georss" xmlns:atom="http://www.w3.org/2005/Atom" >
<channel>
	<title><![CDATA[BOL: Related items]]></title>
	<link>https://bioinformaticsonline.com/related/44722?offset=140</link>
	<atom:link href="https://bioinformaticsonline.com/related/44722?offset=140" rel="self" type="application/rss+xml" />
	<description><![CDATA[]]></description>
	
	<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/bookmarks/view/43806/genomicus-genome-browser-that-enables-users-to-navigate-in-genomes-in-several-dimensions</guid>
	<pubDate>Mon, 28 Feb 2022 23:27:37 -0600</pubDate>
	<link>https://bioinformaticsonline.com/bookmarks/view/43806/genomicus-genome-browser-that-enables-users-to-navigate-in-genomes-in-several-dimensions</link>
	<title><![CDATA[Genomicus: genome browser that enables users to navigate in genomes in several dimensions]]></title>
	<description><![CDATA[<p>Genomicus is a genome browser that enables users to navigate in genomes in several dimensions: linearly along chromosome axes, transversaly across different species, and chronologicaly along evolutionary time.</p>
<p>Once a query gene has been entered, it is displayed in its genomic context in parallel to the genomic context of all its orthologous and paralogous copies in all the other sequenced metazoan genomes. Moreover, Genomicus stores and displays the predicted ancestral genome structure in all the ancestral species within the phylogenetic range of interest.</p>
<p>All the data on extant species displayed in this browser are from&nbsp;<a href="http://www.ensembl.org/">Ensembl</a>.</p>
<p><br><strong>Summary statistics of Genomicus version 105.01:</strong><span>&nbsp;(view species tree in&nbsp;</span><a href="https://www.genomicus.bio.ens.psl.eu/genomicus-105.01/data/SpeciesTree.pdf">pdf</a><span>&nbsp;or&nbsp;</span><a href="https://www.genomicus.bio.ens.psl.eu/genomicus-105.01/data/SpeciesTree.nwk">newick</a><span>)</span><br><br></p>
<table id="introstats">
<tbody>
<tr><th>Number of extant species</th>
<td>200</td>
</tr>
<tr><th>Number of extant genes</th>
<td>4303993</td>
</tr>
<tr><th>&nbsp;</th></tr>
<tr><th>Number of ancestral species</th>
<td>196</td>
</tr>
<tr><th>Number of ancestral genes</th>
<td>4624213</td>
</tr>
<tr><th>Number of ancestral synteny blocks</th>
<td>83342<br><br></td>
</tr>
</tbody>
</table><p>Address of the bookmark: <a href="https://www.genomicus.bio.ens.psl.eu/genomicus-105.01/cgi-bin/search.pl" rel="nofollow">https://www.genomicus.bio.ens.psl.eu/genomicus-105.01/cgi-bin/search.pl</a></p>]]></description>
	<dc:creator>Jit</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/pages/view/44371/steps-to-find-all-the-repeats-in-the-genome</guid>
	<pubDate>Thu, 31 Aug 2023 02:43:28 -0500</pubDate>
	<link>https://bioinformaticsonline.com/pages/view/44371/steps-to-find-all-the-repeats-in-the-genome</link>
	<title><![CDATA[Steps to find all the repeats in the genome !]]></title>
	<description><![CDATA[<div><p>To find repeats in a genome from 2 to 9 length using a Perl script, you can use the RepeatMasker tool with the "--length" option<a href="https://mobilednajournal.biomedcentral.com/articles/10.1186/1759-8753-5-13" target="_blank">[0]</a>. Here's a step-by-step guide:</p></div><div><ol>
<li>Install RepeatMasker: First, you need to install RepeatMasker on your system. You can download it from the RepeatMasker website<a href="https://mobilednajournal.biomedcentral.com/articles/10.1186/1759-8753-5-13" target="_blank">[0]</a>.</li>
</ol></div><div><ol>
<li>Prepare the genome sequence: Make sure you have the genome sequence in a FASTA file format. Let's assume the file is named "genome.fasta".</li>
</ol><blockquote><p>./RepeatMasker -pa &lt;number_of_processors&gt; -nolow -norna -no_is -div &lt;divergence_value&gt; -lib RepeatMaskerLib.embl -gff -xsmall -small -poly -species &lt;species_name&gt; -dir &lt;output_directory&gt; -length &lt;min_length&gt;-&lt;max_length&gt; genome.fasta</p></blockquote><div><p>Replace the following placeholders with appropriate values:</p><ul>
<li><code>&lt;number_of_processors&gt;</code>: The number of processors/threads you want to use for parallel processing.</li>
<li><code>&lt;divergence_value&gt;</code>: The divergence value for the species you are analyzing. You can find divergence values for different species in the RepeatMasker documentation<a href="https://mobilednajournal.biomedcentral.com/articles/10.1186/1759-8753-5-13" target="_blank">[0]</a>.</li>
<li><code>&lt;species_name&gt;</code>: The name of the species you are analyzing.</li>
<li><code>&lt;output_directory&gt;</code>: The directory where you want the output files to be saved.</li>
<li><code>&lt;min_length&gt;</code>&nbsp;and&nbsp;<code>&lt;max_length&gt;</code>: The minimum and maximum lengths of the repeats you want to find (in this case, 2 and 9).</li>
</ul></div><div><ol>
<li>Analyze the output: RepeatMasker will generate several output files, including a .out file. You can parse this file to extract the information you need. There is a Perl tool called "one_code_to_find_them_all.pl" that can help you parse RepeatMasker output files<a href="https://mobilednajournal.biomedcentral.com/articles/10.1186/1759-8753-5-13" target="_blank">[0]</a>. You can download it from the source provided.</li>
</ol></div><div><ol>
<li>Use the provided Perl script: Once you have the "one_code_to_find_them_all.pl" script, you can run it to conveniently parse the RepeatMasker output files. Here's an example of how to use it:</li>
</ol><blockquote><p>perl one_code_to_find_them_all.pl --rm &lt;RepeatMasker_out_file&gt; --length &lt;length_file&gt;</p></blockquote></div><p>&nbsp;</p></div><div><div><p>Replace&nbsp;<code>&lt;RepeatMasker_out_file&gt;</code>&nbsp;with the path to your RepeatMasker .out file, and&nbsp;<code>&lt;length_file&gt;</code>&nbsp;with the path to a file containing the lengths of the reference elements.</p></div><div><p>This script will generate several output files, including .log.txt and .copynumber.csv, which contain quantitative information about the identified repeat elements.</p></div><div><p>Remember to adjust the parameters and options according to your specific needs and the characteristics of your genome.</p></div></div>]]></description>
	<dc:creator>Neel</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/blog/view/45251/aurora-a-new-detective-for-bacterial-genomes</guid>
	<pubDate>Fri, 21 Aug 2026 11:31:00 -0500</pubDate>
	<link>https://bioinformaticsonline.com/blog/view/45251/aurora-a-new-detective-for-bacterial-genomes</link>
	<title><![CDATA[Aurora: A New Detective for Bacterial Genomes]]></title>
	<description><![CDATA[<p>Imagine trying to solve a mystery with thousands of clues&mdash;but some of the clues are labelled incorrectly.</p><p>That is the challenge researchers face when studying how bacteria adapt to different environments. A bacterial gene may appear to be linked to a particular habitat, when the real reason is simply that closely related bacteria happen to live there.</p><p>In their 2025 Genome Biology paper, Bujdo&scaron;, Walter, and O&rsquo;Toole introduce aurora, a machine-learning tool designed to tackle this problem.</p><p>Aurora identifies potentially mislabeled or unusual bacterial strains before performing genome-wide association studies (GWAS). By cleaning up the dataset and accounting for bacterial evolutionary relationships, it can help researchers find genetic features that are more genuinely connected to habitat adaptation.</p><p>The researchers tested aurora using simulated and real bacterial datasets and found that it could recover important genetic associations even when datasets contained misleading labels.</p><p>The bigger lesson is simple: better biological discoveries often begin with better data.</p><p>Aurora gives researchers a new way to separate real genetic clues from misleading ones&mdash;and could help us better understand how bacteria adapt, survive, and evolve in the environments they call home.</p><p>Based on Bujdo&scaron; et al., &ldquo;aurora: a machine learning GWAS tool for analyzing microbial habitat adaptation,&rdquo; Genome Biology (2025).[Read the original paper](https://link.springer.com/article/10.1186/s13059-025-03524-7?)</p>]]></description>
	<dc:creator>BioStar</dc:creator>
</item>

<item>
  <guid isPermaLink='true'>https://bioinformaticsonline.com/researchlabs/view/45296/luo-lab-symbiosis-genomics-evolution</guid>
  <pubDate>Wed, 09 Sep 2026 03:30:30 -0500</pubDate>
  <link></link>
  <title><![CDATA[Luo Lab | Symbiosis Genomics &amp; Evolution]]></title>
  <description><![CDATA[
<p>We study the evolutionary genomics of marine invertebrates to understand their origins and diversity. Our lab combines high-throughput sequencing and single-cell transcriptomics to explore a wide range of non-model systems. We are particularly interested in how evolutionary novelty arises, with a focus on animal development and photosymbiosis.</p>

<p>Research Directions</p>

<p>Stony corals: evolution of novelty and photosymbiosis</p>

<p>Symbiotic acoels: cell type evolution and photosymbiosis</p>

<p>Animal genomes: structural evolution and gene regulation</p>

<p>https://sgel.biodiv.tw/home</p>
]]></description>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/blog/view/45358/the-variant-everyone-ignored</guid>
	<pubDate>Mon, 05 Oct 2026 12:14:20 -0500</pubDate>
	<link>https://bioinformaticsonline.com/blog/view/45358/the-variant-everyone-ignored</link>
	<title><![CDATA[The Variant Everyone Ignored]]></title>
	<description><![CDATA[<p>Consider a scenario in which a patient's genome has been sequenced. Among billions of DNA bases, a structural alteration may explain the patient's disease. Multiple advanced algorithms analyze the data, yet only one detects the variant, while the others do not. In standard bioinformatics workflows, such a solitary result is often regarded as unreliable and subsequently discarded. Although the solution exists within the data, prevailing computational protocols may overlook it.</p><p>A recent study published in Genome Biology (https://link.springer.com/article/10.1186/s13059-026-04280-y) addressed this challenge by introducing dicast (https://github.com/burgshrimps/dicast), a machine-learning approach for detecting structural variants in short-read sequencing data. Structural variants, such as large deletions, insertions, duplications, and inversions, can have significant biological and clinical implications, yet they are challenging to identify with short-read technologies. Because different detection methods frequently yield divergent results, researchers commonly employ consensus calling, considering a variant valid only if multiple tools detect it. While this approach reduces false positives, it relies on the potentially flawed assumption that the majority is always correct.</p><p>The researchers explored the impact of evaluating the supporting evidence for each variant, rather than simply tallying the number of algorithms that identified it. To establish a ground truth, they analyzed nine genomes using multiple sequencing technologies and 15 detection methods, initially identifying approximately 35 million potential variants. Through extensive filtering, evidence integration, and manual review of over 11,500 variants, they developed a robust benchmark comprising more than 236,000 structural variants. The findings underscored the complexity of the problem: short-read methods detected fewer than half of deletions and less than 10 percent of insertions, with performance declining markedly in repetitive genomic regions. In contrast, long-read technologies demonstrated superior detection capabilities. However, replacing the substantial volume of existing short-read data in clinical and research settings is not immediately feasible. Consequently, the researchers questioned whether short-read data might harbor more information than conventional analytical pipelines currently extract.</p><p>This line of inquiry led to the development of dicast. Rather than merely confirming agreement among multiple tools, dicast identifies patterns in sequencing data, including split and clipped reads, discordant read pairs, alignment characteristics, and the surrounding genomic context. An XGBoost machine-learning model evaluates which combinations of these signals are indicative of genuine structural variants. Thus, the approach shifts from tallying algorithmic consensus to interpreting the underlying evidence.</p><p>The researchers subsequently conducted a targeted evaluation by examining structural variants detected by only a single short-read tool, which are typically missed by consensus-based approaches. dicast successfully recovered approximately 81% of these single-caller deletions, insertions, and duplications. The signals for these variants were present in the data, but conventional filtering methods failed to integrate them effectively.</p><p>The utility of dicast was further demonstrated in cohorts with rare diseases, including congenital limb malformations, atrial fibrillation, and neuromuscular disorders. In one instance, dicast achieved a deletion recall rate of approximately 0.96, compared to 0.74 using consensus calling. The median number of variants requiring manual review was 29 per sample. Among 31 experimentally validated variants that standard filters would have missed, dicast identified 12, whereas consensus calling detected only one.</p><p>Overall, dicast identified approximately 20 percent more potential disease-causing deletions than consensus-based methods. While a 20 percent increase may appear modest, in clinical genomics such improvements can have significant practical implications. Missing a deletion may leave a case unresolved, whereas detecting a structural variant can provide critical diagnostic insights.</p><p>The study does not claim that machine learning has rendered short-read sequencing superior to long-read approaches. Instead, the results underscore the effectiveness of long-read sequencing for structural variant detection. However, dicast highlights a more nuanced perspective: substantial biological information may still be recoverable from the extensive short-read datasets already available.</p><p>The principal lesson extends beyond the detection of structural variants. For many years, bioinformatics pipelines have relied on threshold-based criteria, such as minimum coverage, quality scores, or support from multiple tools. While these rules are useful, biological phenomena do not always conform to rigid checklists; multiple weak signals, when considered collectively, can provide compelling evidence.</p><p>This perspective prompts consideration of the solitary variant: one algorithm identifies it, while several others do not. Traditional consensus techniques might have dismissed it, yet machine learning approaches evaluate the available evidence to determine whether the variant is plausible.</p><p>Occasionally, the most significant variant within a genome is the one that is almost universally overlooked.</p><p>Read more at&nbsp;https://link.springer.com/article/10.1186/s13059-026-04280-y</p>]]></description>
	<dc:creator>BioStar</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/bookmarks/view/23253/resolving-the-complexity-of-the-human-genome-using-single-molecule-sequencing</guid>
	<pubDate>Sat, 11 Jul 2015 12:47:34 -0500</pubDate>
	<link>https://bioinformaticsonline.com/bookmarks/view/23253/resolving-the-complexity-of-the-human-genome-using-single-molecule-sequencing</link>
	<title><![CDATA[Resolving the complexity of the human genome using single-molecule sequencing]]></title>
	<description><![CDATA[<p>The human genome is arguably the most complete mammalian reference assembly yet more than 160 euchromatic gaps remain and aspects of its structural variation remain poorly understood ten years after its completion. The results in this paper https://www.genomeweb.com/sequencing/team-uses-single-molecule-sequencing-close-gaps-chart-complexity-human-reference suggest a greater complexity of the human genome in the form of variation of longer and more complex repetitive DNA that can now be largely resolved with the application of this longer-read sequencing technology.</p>
<p>&nbsp;</p><p>Address of the bookmark: <a href="http://www.nature.com/nature/journal/v517/n7536/full/nature13907.html" rel="nofollow">http://www.nature.com/nature/journal/v517/n7536/full/nature13907.html</a></p>]]></description>
	<dc:creator>Rahul Agarwal</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/bookmarks/view/37576/lrcstats-a-tool-for-evaluating-long-reads-correction-methods</guid>
	<pubDate>Wed, 22 Aug 2018 11:05:04 -0500</pubDate>
	<link>https://bioinformaticsonline.com/bookmarks/view/37576/lrcstats-a-tool-for-evaluating-long-reads-correction-methods</link>
	<title><![CDATA[LRCstats: a tool for evaluating long reads correction methods]]></title>
	<description><![CDATA[<p><span>LRCstats is an open-source pipeline for benchmarking DNA long read correction algorithms for long reads outputted by third generation sequencing technology such as machines produced by Pacific Biosciences. The reads produced by third generation sequencing technology, as the name suggests, are longer in length than reads produced by next generation sequencing technologies, such as those produced by Illumina. However, long reads are plagued by high error rates, which can cause issues in downstream analysis. Long read correction algorithms reduce the error rate of long reads either through self-correcting methods or using accurate, short reads outputted by next generation sequencing technologies to correct long reads.</span></p><p>Address of the bookmark: <a href="https://github.com/cchauve/lrcstats" rel="nofollow">https://github.com/cchauve/lrcstats</a></p>]]></description>
	<dc:creator>Aaryan Lokwani</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/blog/view/44227/common-methods-to-discover-tandem-repeats</guid>
	<pubDate>Thu, 09 Mar 2023 02:40:52 -0600</pubDate>
	<link>https://bioinformaticsonline.com/blog/view/44227/common-methods-to-discover-tandem-repeats</link>
	<title><![CDATA[Common methods to discover tandem repeats]]></title>
	<description><![CDATA[<div><div><div><div><div><div><div><div><div><div><p>Tandem repeats are DNA sequences that are repeated in a contiguous manner in the genome. These sequences are often used as genetic markers and are important in many areas of genetics and genomics research. Here are some methods for discovering tandem repeats in genomes:</p><ol>
<li>
<p>Tandem Repeat Finder: Tandem Repeat Finder is a software tool that identifies tandem repeats in DNA sequences. It is available for free download and can be used on both nucleotide and protein sequences. The tool uses a statistical algorithm to identify repeats based on their length, copy number, and overall composition.</p>
</li>
<li>
<p>RepeatMasker: RepeatMasker is another software tool that can identify tandem repeats in DNA sequences. It works by comparing the input sequence to a database of known repeats and then identifies any tandem repeats that match those in the database.</p>
</li>
<li>
<p>PCR-based methods: Polymerase chain reaction (PCR) can be used to amplify and detect tandem repeats in genomic DNA. PCR primers are designed to flank the tandem repeat region, and amplification of the target DNA fragment can be visualized on a gel. This method can be useful for detecting novel tandem repeats and for genotyping.</p>
</li>
<li>
<p>Southern blotting: Southern blotting is a classic method for detecting DNA fragments in a sample. It can be used to detect tandem repeats by digesting genomic DNA with a restriction enzyme, separating the fragments by gel electrophoresis, and then probing the blot with a tandem repeat-specific probe.</p>
</li>
</ol><p>Overall, a combination of these methods can be used to comprehensively identify tandem repeats in genomes.</p></div></div></div></div></div></div></div></div></div></div>]]></description>
	<dc:creator>BioStar</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/pages/view/27321/slurm-basics</guid>
	<pubDate>Fri, 13 May 2016 04:42:24 -0500</pubDate>
	<link>https://bioinformaticsonline.com/pages/view/27321/slurm-basics</link>
	<title><![CDATA[SLURM basics !]]></title>
	<description><![CDATA[<p><a href="http://bioinformaticsonline.com/bookmarks/view/27238/slurm" target="_blank">SLURM</a> is a queue management system and stands for Simple Linux Utility for Resource Management. SLURM was developed at the Lawrence Livermore National Lab and currently runs some of the largest compute clusters in the world.</p><p>SLURM is similar in many ways to most other queue systems. You write a batch script then submit it to the queue manager. The queue manager then schedules your job to run on the queue (or partition in SLURM parlance) that you designate. Below we will provide an outline of how to submit jobs to SLURM, how SLURM decides when to schedule your job and how to monitor progress.</p><p>SLURM has a number of valuable features compared to other job management systems:</p><ul>
<li><em>Kill and Requeue</em> SLURM&rsquo;s ability to kill and requeue is superior to that of other systems. It waits for jobs to be cleared before scheduling the high priority job. It also does kill and requeue on memory rather than just on core count.</li>
<li><em>Memory</em> Memory requests are sacrosanct in SLURM. Thus the amount of memory you request at run time is guaranteed to be there. No one can infringe on that memory space and you cannot exceed the amount of memory that you request.</li>
<li><em>Accounting Tools</em> SLURM has a back end database which stores historical information about the cluster. This information can be queried by the users who are curious about how much resources they have used.</li>
</ul><p><strong>Summary of SLURM commands</strong></p><p>The table below shows a summary of SLURM commands. These commands are described in more detail below along with links to the SLURM doc site.</p><table>
<tbody>
<tr><th>&nbsp;</th><th>SLURM</th><th>SLURM Example</th></tr>
<tr>
<td>Submit a batch serial job</td>
<td><a href="http://slurm.schedmd.com/sbatch.html">sbatch</a></td>
<td><code>sbatch runscript.sh</code></td>
</tr>
<tr>
<td>Run a script interatively</td>
<td><a href="http://slurm.schedmd.com/srun.html">srun</a></td>
<td><code>srun --pty -p interact -t 10 --mem 1000 /bin/bash /bin/hostname</code></td>
</tr>
<tr>
<td>Kill a job</td>
<td><a href="http://slurm.schedmd.com/scancel.html">scancel</a></td>
<td><code>scancel 999999</code></td>
</tr>
<tr>
<td>View status of queues</td>
<td><a href="http://slurm.schedmd.com/squeue.html">squeue</a></td>
<td><code>squeue -u akitzmiller</code></td>
</tr>
<tr>
<td>Check current job by id</td>
<td><a href="http://slurm.schedmd.com/squeue.html">sacct</a></td>
<td><code>sacct -j 999999</code></td>
</tr>
</tbody>
</table>]]></description>
	<dc:creator>Radha Agarkar</dc:creator>
</item>
<item>
	<guid isPermaLink="true">https://bioinformaticsonline.com/blog/view/44720/a-beginners-guide-to-using-kraken-for-taxonomic-classification</guid>
	<pubDate>Fri, 13 Dec 2024 11:29:03 -0600</pubDate>
	<link>https://bioinformaticsonline.com/blog/view/44720/a-beginners-guide-to-using-kraken-for-taxonomic-classification</link>
	<title><![CDATA[A Beginner&#039;s Guide to Using Kraken for Taxonomic Classification]]></title>
	<description><![CDATA[<div>Kraken is a popular bioinformatics tool designed for fast and accurate taxonomic classification of metagenomic sequences. Its efficiency and precision make it a go-to resource for analyzing microbial communities, including bacteria, viruses, archaea, and fungi. Whether you're new to bioinformatics or experienced in the field, Kraken is an indispensable tool for taxonomic analysis.</div><div><div><div><div dir="auto"><div><div><p>In this blog, we&rsquo;ll walk through the basics of Kraken, from installation to running an analysis, and highlight its key features and applications.</p><h4><strong>What is Kraken?</strong></h4><p>Kraken is a sequence classification tool that assigns taxonomic labels to DNA sequences using exact k-mer matching. It uses a reference database of genomes, dividing sequences into k-mers and identifying matches in a computationally efficient way.</p><h4><strong>Key Features of Kraken</strong></h4><ul>
<li><strong>Speed</strong>: Kraken processes data much faster than alignment-based methods.</li>
<li><strong>Accuracy</strong>: It uses a precise k-mer matching algorithm for high-resolution taxonomic assignments.</li>
<li><strong>Scalability</strong>: It can handle large metagenomic datasets.</li>
<li><strong>Custom Databases</strong>: You can build and use custom databases tailored to your research needs.</li>
</ul><h4><strong>Installing Kraken</strong></h4><ol>
<li>
<p><strong>System Requirements</strong></p>
<ul>
<li>A Unix-based operating system (Linux/macOS).</li>
<li>Sufficient computational resources for database building (RAM and disk space).</li>
</ul>
</li>
<li>
<p><strong>Installation Steps</strong></p>
<ul>
<li>Clone the Kraken repository from GitHub:
<div>
<div>&nbsp;</div>
<div dir="ltr"><code>git <span style="font-size: 12.8px; font-weight: normal;">clone</span> https://github.com/DerrickWood/kraken.git <span style="font-size: 12.8px; font-weight: normal;">cd</span> kraken </code></div>
</div>
</li>
<li>Compile the Kraken binaries:
<div>
<div>&nbsp;</div>
<div dir="ltr"><code>make </code></div>
</div>
</li>
<li>Add Kraken to your PATH for easy access:
<div>
<div>&nbsp;</div>
<div dir="ltr"><code><span style="font-size: 12.8px; font-weight: normal;">export</span> PATH=<span style="font-size: 12.8px; font-weight: normal;">$PATH</span>:/path/to/kraken </code></div>
</div>
</li>
</ul>
</li>
</ol><h4><strong>Preparing a Database</strong></h4><p>Kraken requires a database of reference genomes. You can use a pre-built database or create a custom one.</p><ol>
<li>
<p><strong>Downloading a Pre-built Database</strong><br />Kraken offers pre-built databases, such as the <em>MiniKraken</em> database, which is lightweight and suitable for smaller datasets. Download it using:</p>
<div>
<div dir="ltr"><code>kraken-build --download-library minikraken </code></div>
</div>
</li>
<li>
<p><strong>Building a Custom Database</strong><br />To include specific genomes, download FASTA files and build the database:</p>
<div>
<div dir="ltr"><code>kraken-build --download-library bacteria --threads 4 --db my_database kraken-build --build --db my_database </code></div>
</div>
<p>This process may take considerable time and resources, depending on the size of the database.</p>
</li>
</ol><h4><strong>Running Kraken</strong></h4><p>Once the database is ready, you can classify sequences.</p><ol>
<li>
<p><strong>Basic Usage</strong><br />Use the following command to classify sequences:</p>
<div>
<div dir="ltr"><code>kraken --db my_database --threads 4 --fastq-input input_sequences.fastq --output kraken_output.txt </code></div>
</div>
<p>Key options:</p>
<ul>
<li><code>--db</code>: Specifies the database.</li>
<li><code>--threads</code>: Number of threads for parallel processing.</li>
<li><code>--fastq-input</code>: Indicates input file format (FASTQ/FASTA).</li>
</ul>
</li>
<li>
<p><strong>Interpreting Results</strong><br />Kraken generates an output file with columns for sequence IDs, taxonomic classifications, and the confidence score.</p>
</li>
</ol><h4><strong>Visualizing Kraken Results</strong></h4><p>Kraken results can be visualized using tools like <strong>Krona</strong> or converted to human-readable reports using <code>kraken-report</code>.</p><ol>
<li>
<p><strong>Generate a Report</strong></p>
<div>
<div dir="ltr"><code>kraken-report --db my_database kraken_output.txt &gt; kraken_report.txt </code></div>
</div>
</li>
<li>
<p><strong>Krona Visualization</strong><br />Install Krona and convert Kraken output for visualization:</p>
<div>
<div dir="ltr"><code>cut -f2,3 kraken_output.txt | ktImportTaxonomy -o krona_output.html </code></div>
</div>
<p>Open the HTML file in your browser to interactively explore the taxonomic classifications.</p>
</li>
</ol><h4><strong>Advanced Usage</strong></h4><ol>
<li>
<p><strong>Confidence Thresholds</strong><br />Adjust the confidence threshold for classification using the <code>--confidence</code> option. Higher values reduce false positives but may miss some true positives:</p>
<div>
<div dir="ltr"><code>kraken --db my_database --confidence 0.1 --fastq-input input.fastq </code></div>
</div>
</li>
<li>
<p><strong>Paired-End Reads</strong><br />For paired-end sequencing data, use:</p>
<div>
<div dir="ltr"><code>kraken --db my_database --paired reads_1.fastq reads_2.fastq </code></div>
</div>
</li>
<li>
<p><strong>Customizing K-mers</strong><br />Kraken allows you to set custom k-mer lengths during database building for specific applications.</p>
</li>
</ol><h4><strong>Applications of Kraken</strong></h4><ul>
<li><strong>Microbial Ecology</strong>: Characterizing microbial communities in soil, water, and the human microbiome.</li>
<li><strong>Pathogen Detection</strong>: Identifying pathogens in clinical samples.</li>
<li><strong>Fungal Research</strong>: Analyzing fungal diversity in metagenomic datasets.</li>
<li><strong>Environmental Monitoring</strong>: Tracking microbial populations in diverse habitats.</li>
</ul><h4><strong>Conclusion</strong></h4><p>Kraken is a versatile and efficient tool for taxonomic classification in metagenomics. Its speed, accuracy, and flexibility make it a favorite among bioinformaticians. By following this guide, you can set up and use Kraken to unlock insights into microbial and fungal communities, paving the way for discoveries in ecology, medicine, and biotechnology.</p></div></div></div></div></div></div>]]></description>
	<dc:creator>Neel</dc:creator>
</item>

</channel>
</rss>