BOL: Related items

Synima: a Synteny imaging tool for annotated genome assemblies

Abhimanyu Singh — Tue, 30 Oct 2018 10:49:13 -0500

Synima written in Perl, which uses the graphical features of R. Synima takes orthologues computed from reciprocal best BLAST hits or OrthoMCL, and DAGchainer, and outputs an overview of genome-wide synteny in PDF. Each of these programs are included with the Synima package, and a pipeline for their use. Synima has a range of graphical parameters including size, colours, order, and labels, which are specified in a config file generated by the first run of Synima – and can be subsequently edited. Synima runs quickly on a command line to generate informative and publication quality figures. Synima is open source and freely available from https://github.com/rhysf/Synima under the MIT License.

Address of the bookmark: https://github.com/rhysf/Synima

Uncovering Evolution’s Blueprint: How ntSynt Is Changing Comparative Genomics

Jitendra Narayan — Mon, 19 Oct 2026 03:08:49 -0500

Over millions of years, evolution has shaped all life on Earth, leaving clues in the DNA of every organism. While different species look and act very differently, their genomes still hold signs of a shared evolutionary past. These connections show up not just in similar DNA sequences, but also in how genetic material is arranged on chromosomes. To study these patterns, scientists use a concept called synteny, which helps them track changes in genomes, chromosome rearrangements, and relationships between species. However, as genome sequencing technology has advanced and thousands of high-quality genomes are now available, finding conserved regions across many genomes has become a much tougher computational challenge.

To tackle this problem, researchers developed a new bioinformatics tool called ntSynt. It was first introduced in a 2025 study in BMC Biology titled “ntSynt: multi-genome synteny detection using minimizer graph mappings”. This tool (https://github.com/BirolLab/ntSynt) helps researcher find conserved genomic regions across several species without relying on traditional whole-genome alignments or gene annotations. Instead, ntSynt uses short DNA sequences called minimizers as landmarks. It finds minimizers shared by different genomes and maps their relationships in a graph, making it possible to spot large genomic regions that have kept a similar structure over time. The tool uses Bloom filters and graph-based mapping, which lets scientists analyze many genomes at once while saving memory and processing time.

The team tested ntSynt using both simulated data and real genomic sequences from groups like humans, chimpanzees, bonobos, gorillas, rodents, and bees. Their results showed that ntSynt can find conserved genomic regions and spot structural differences between species. In simulated tests, ntSynt identified syntenic blocks with over 97% accuracy. One standout example involved eleven bee genomes from the genus Andrena, which have a lot of variation in chromosome organization. Despite these differences, ntSynt found conserved regions covering about 85% of the smallest bee genome, completing the analysis in just 14.7 minutes and using less than 4 GB of memory. These findings highlight ntSynt’s potential for large-scale comparative genomics, where efficiency is crucial as more genomes become available.

An interesting result came up when the researchers compared primate genomes. When they looked at regions conserved between humans and other great apes, ntSynt flagged what looked like a large deletion in one gorilla genome assembly. After checking with long-read sequencing data, they found that the missing section was likely a mistake in the assembly, not a real evolutionary change. This means ntSynt can help not only with studying evolutionary relationships but also with spotting possible errors in genome assemblies. By highlighting unexpected breaks in regions that are usually conserved, the tool helps scientists tell apart true evolutionary changes from technical mistakes in reference sequences.

The importance of ntSynt becomes even clearer when we look at global projects to sequence and study Earth’s biodiversity. Projects like the Earth BioGenome Project aim to create genomic resources for many different organisms, opening up new ways to explore the history of life. But generating genomic data is just the beginning; making sense of these relationships requires powerful and scalable tools. ntSynt helps by letting researchers study chromosome evolution, conserved genome structures, and rearrangements across many species. While the tool has some limits, especially with detecting duplicated regions or analyzing very different genomes, its speed and scalability make it a valuable tool for modern comparative genomics.

The creation of ntSynt marks a significant advancement in our understanding of how genomes have evolved and become diverse over Earth's history. Since each conserved region in the genome is evidence of common ancestry and each rearrangement gives hinThe development of ntSynt is a big step forward in understanding how genomes have changed and diversified over time. Each conserved region in a genome points to shared ancestry, and each rearrangement offers clues about evolutionary events in different lineages. ntSynt helps scientists spot these patterns more easily, opening up new ways to study genome evolution across the tree of life. Evolution’s story isn’t just in the DNA sequence, but also in how those sequences are arranged and preserved over millions of years. Tools like ntSynt are helping scientists read this hidden story more clearly and reveal the deep genomic connections that link all life on Earth.

More at https://link.springer.com/article/10.1186/s12915-025-02455-w?

JCVI:Python utility libraries on genome assembly, annotation and comparative genomics

Jit — Tue, 17 Mar 2020 06:19:06 -0500

Collection of Python libraries to parse bioinformatics files, or perform computation related to assembly, annotation, and comparative genomics.

https://github.com/tanghaibao/jcvi

More at https://github.com/tanghaibao/jcvi/wiki

Address of the bookmark: https://github.com/tanghaibao/jcvi

Ancient whole genome duplication (WGD) detection tools !

Rahul Nayak — Sun, 07 Mar 2021 00:32:44 -0600

There are two methods for ancient WGD detection, one is collinearity analysis, and the other is based on the Ks distribution map. Among them, Ks is defined as the average number of synonymous substitutions at each synonymous site, and there is also a Ka corresponding to it, which refers to the average number of non-synonymous substitutions at each non-synonymous site.

At present, some people have posted articles about the analysis process of WGD. I searched for the keyword "wgd pipeline" and found the following:

GenoDup: https:// github.com/MaoYafei/GenoDup-Pipeline
https://peerj.com/articles/6303/
WGDdetector: https:// github.com/yongzhiyang2 012/WGDdetector
https://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-019-2670-3
wgd: https:// github.com/arzwa/wgd
https://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-016-1142-2#Sec1
https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-017-0399-x
GeNoGAP https://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-016-1142-2
https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-017-0399-x
https://github.com/dfguan/purge_dups
https://www.biorxiv.org/content/10.1101/2020.01.24.917997v1

This article introduces the usage of wgd.

Wgd cannot be installed directly with bioconda at present, so it is a little troublesome to install, because it depends on a lot of software. wgd depends on the following software

BLAST
MCL
MUSCLE/MAFFT/PRANK
PAML
PhyML/FastTree
i-ADHoRe

But the good news is that most of the software it depends on can be installed with bioconda

conda create -n wgd python=3.5 blast mcl muscle mafft prank paml fasttree cmake libpng mpi=1.0=mpich
conda activate wgd

Here mpi=1.0=mpich is selected, because i-adhore depends on mpich. If openmpi is installed, an error will appear while loading shared libraries: libmpi_cxx.so.40: cannot open shared object file: No such file or directory

After that, the installation is much simpler

git clone https://github.com/arzwa/wgd.git
cd wgd
pip install .
pip install git+https://github.com/arzwa/wgd.git
For i-ADHoRe, you need to register at http:// bioinformatics.psb.ugent.be /webtools/i-adhore/licensing/Agree to the license to download i-ADHoRe-3.0

Since my miniconda3 installed ~/opt/, the installation path is so~/opt/miniconda3/envs/wgd/

tar -zxvf i-adhore-3.0.01.tar.gz
cd i-adhore-3.0.01
mkdir -p build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=~/opt/miniconda3/envs/wgd/
make -j 4
make insatall

Take the sugarcane genome Saccharum spontaneum L as an example. The genome is 8-ploid with 32 chromosomes (2n = 4x8 = 32)

Download the tutorial for CDS and GFF annotation files

mkdir -p wgd_tutorial && cd wgd_tutorial
wget http://www.life.illinois.edu/ming/downloads/Spontaneum_genome/Sspon.v20190103.cds.fasta.gz
wget http://www.life.illinois.edu/ming/downloads/Spontaneum_genome/Sspon.v20190103.gff3.gz
gunzip *.gz

First conda activate wgdstart our analysis environment, and then start the analysis

Step 1 : Use to wgd mclidentify homologous genes in the genome

wgd mcl -n 20 --cds --mcl -s Sspon.v20190103.cds.fasta -o Sspon_cds.out

Step 2 : Use to wgd ksdbuild Ks distribution

wgd ksd --n_threads 80 Sspon_cds.out/Sspon.v20190103.cds.fasta.blast.tsv.mcl Sspon.v20190103.cds.fasta

Step 3 : If the quality of the genome is good, then wgd syncollinearity analysis can be used . It can help us find the collinearity block in the genome and the corresponding anchor point

wgd syn --feature gene --gene_attribute ID \
-ks wgd_ksd/Sspon.v20190103.cds.fasta.ks.tsv \
Sspon.v20190103.gff3 Sspon_cds.out/Sspon.v20190103.cds.fasta.blast.tsv.mcl

For more reading - There are 9 sub-modules in WGD

kde: KDE fitting to the Ks distribution
ksd: Ks distribution construction
mcl: BLASP comparison of All-vs-ALl + MCL classification analysis.
mix: Hybrid modeling of Ks distribution.
pre: preprocess the CDS file
syn: Call I-ADHoRe 3.0 to use GFF files for collinearity analysis
viz: draw histogram and density plot
wf1: Ks standard analysis procedure of the whole genome paranome (paranome), call mcl, ksd and syn
wf2: Ks standard analysis procedure of one-vs-one homologous gene (ortholog), call wcl and kSD

Claus-Peter Stelzer Lab

Mon, 15 Mar 2021 15:24:41 -0500

Interested in various topics at the intersection of ecology and evolution. In my research I use rotifers as model organisms for experimental studies at the individual and population level. Rotifers are ideally suited for this, because populations of thousands can be kept in small containers in the lab, while single individuals can still be handled conveniently.

More at https://www.uibk.ac.at/limno/personnel/stelzer/index.html.en#research

04- Informatics Approach to Cancer - Interview with Dr. Joel Saltz

Mon, 07 Oct 2013 14:35:43 -0500

For additional information visit http://www.cancerquest.org/joel-saltz-interview. Dr. Joel Saltz is a Professor in the Departments of Pathology, Biostatistics and Bioinformatics, and Mathematics and Computer Science at Emory University. Dr. Saltz's research on bioinformatics spans several disciplines. One project involves applying computer analysis to medical imaging to yield better results for patients. As an example, a computer program may able to help doctors detect small cancers in a CT scan or mammogram. In this interview segment, Dr. Saltz discusses the informatics approach to cancer. To learn more about cancer and watch additional interviews, please visit the CancerQuest website at http://www.cancerquest.org.

Oldest Hominin DNA Sequenced

Surajeet — Fri, 27 Dec 2013 19:58:31 -0600

Matthias Meyer and his team from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have developed new techniques for retrieving and sequencing highly degraded ancient DNA. They then joined forces with Juan-Luis Arsuaga and applied the new techniques to a cave bear from the Sima de los Huesos site. After this success, the researchers sampled two grams of bone powder from a hominin thigh bone from the cave. They extracted its DNA and sequenced the genome of the mitochondria or mtDNA, a small part of the genome that is passed down along the maternal line and occurs in many copies per cell. The researchers then compared this ancient mitochondrial DNA with Neandertals, Denisovans, present-day humans, and apes.

From the missing mutations in the old DNA sequences the researchers calculated that the Sima hominin lived about 400,000 years ago. They also found that it shared a common ancestor with the Denisovans, an extinct archaic group from Asia related to the Neandertals, about 700,000 years ago. "The fact that the mtDNA of the Sima de los Huesos hominin shares a common ancestor with Denisovan rather than Neandertal mtDNAs is unexpected since its skeletal remains carry Neandertal-derived features," says Matthias Meyer. Considering their age and Neandertal-like features, the Sima hominins were likely related to the population ancestral to both Neandertals and Denisovans. Another possibility is that gene flow from yet another group of hominins brought the Denisova-like mtDNA into the Sima hominins or their ancestors.

Reference

http://www.sciencedaily.com/releases/2013/12/131204132018.htm

Landry Lab

Thu, 17 Jul 2014 14:33:57 -0500

EVOLUTIONARY AND INTEGRATIVE CELL BIOLOGY

Our research is at the crossroad between cell biology, ecological genomics, systems biology, molecular evolution and population genetics. We study the architecture and evolution of protein and signalling networks.

More at http://landrylab.ibis.ulaval.ca/

Alignment of closely related whole genomes/scaffolds

Rahul Nayak — Fri, 29 Jan 2016 10:37:27 -0600

With the relative ease and low cost of current generation sequencing technologies has led to a dramatic increase in the number of sequenced genomes for species across the tree of life. This increasing volume of data requires tools that can quickly compare multiple whole-genome sequences, millions of base pairs in length, to aid in the study of populations, pan-genomes, and genome evolution.This bookmaks have been created to report new tools for whole genome alignments.

Please report new whole genome alignment tools under comment sections.

Address of the bookmark: http://www.cs.utoronto.ca/~brudno/721.full.pdf

Lawley Lab

Mon, 09 May 2016 03:29:51 -0500

Lawley Lab are covered with a complex microbial community, known as our microbiota, which plays important roles in our physiology, immunity, metabolism and sustenance. Within the human gastrointestinal tract alone there are over 1,000 bacterial species, which amounts to approximately 10 times more cells than we harbor in our entire body and 200 times more genes than are found within our genome. Lawley Lab are really a 'supraorganism' consisting of our 'human' and 'microbial' selves.

More at http://www.sanger.ac.uk/science/groups/lawley-lab