BOL: Related items

FastANI: fast alignment-free computation of whole-genome Average Nucleotide Identity (ANI)

Jit — Fri, 13 Jul 2018 17:27:01 -0500

FastANI is developed for fast alignment-free computation of whole-genome Average Nucleotide Identity (ANI). ANI is defined as mean nucleotide identity of orthologous gene pairs shared between two microbial genomes. FastANI supports pairwise comparison of both complete and draft genome assemblies. Its underlying procedure follows a similar workflow as described by Goris et al. 2007. However, it avoids expensive sequence alignments and uses Mashmap as its MinHash based sequence mapping engine to compute the orthologous mappings and alignment identity estimates. Based on our experiments with complete and draft genomes, its accuracy is on par with BLAST-based ANI solver and it achieves two to three orders of magnitude speedup. Therefore, it is useful for pairwise ANI computation of large number of genome pairs. More details about its speed, accuracy and potential applications are described here: "High-throughput ANI Analysis of 90K Prokaryotic Genomes Reveals Clear Species Boundaries".

Address of the bookmark: https://github.com/ParBLiSS/FastANI

MetaPlotR: a Perl/R pipeline for plotting metagenes of nucleotide modifications and other transcriptomic sites

Neel — Mon, 05 Nov 2018 08:12:45 -0600

An increasing number of studies are mapping protein binding and nucleotide modifications sites throughout the transcriptome. Often, these sites cluster in certain regions of the transcript, giving clues to their function. Hence, it is informative to summarize where in the transcript these sites occur. A metagene is a simple and effective tool for visualizing the distribution of sites along a simplified transcript model. In this work, we introduce MetaPlotR, a Perl/R pipeline for creating metagene plots.

Address of the bookmark: https://github.com/olarerin/metaPlotR

What Junk DNA? It’s an Operating System

Rahul Agarwal — Mon, 19 Aug 2013 15:24:26 -0500

The report adds to growing experimental support for the idea that all that extra stuff in the human genes, once referred to as “junk DNA,” is more than functionless, space-filling material that happens to make up nearly 98% of the genome. The paper adds to a growing body of knowledge establishing a considerable role for this material in the regulation of gene expression and its potential role in human disease.

Address of the bookmark: http://www.genengnews.com/keywordsandtools/print/3/32115/

LAPTI Lab

Thu, 12 Dec 2013 18:19:12 -0600

The main theme of our research is the understanding of how genetic information is decoded from DNA into RNA and proteins. Someone may find this topic a little strange and argue that we already know how this is happening.

Translational recoding.

RNA editing.

Evolution of the genetic code and translation.

More at http://lapti.ucc.ie/research.html

Lab page http://lapti.ucc.ie/index.html

Chekulaevalab

Tue, 12 Jan 2016 02:32:03 -0600

Focusing on understanding the molecular mechanisms that regulate mRNA translation, localization and stability and role of non-coding RNAs in this process. Up to 90% of human DNA is estimated to be transcribed into so called non-coding RNAs that are not translated into proteins. Many of them act as potent modifiers of gene expression. miRNAs are a class of such short non-coding RNAs. They regulate expression of more than a half of eukaryotic genes, thus, affecting multiple biological processes, including cell proliferation, differentiation, apoptosis and senescence. Not surprisingly, miRNAs are involved in many human pathologies, including cancer and neurological disorders and hold great potential as drug targets, disease markers, as well as therapeutic agents.
Our lab is located at the Berlin Institute for Medical Systems Biology (BIMSB), a part of the Max Delbrück Center for Molecular Medicine (MDC).

http://www.chekulaevalab.org/

Barrnap: Bacterial ribosomal RNA predictor

Abhimanyu Singh — Fri, 12 May 2017 09:24:41 -0500

Barrnap predicts the location of ribosomal RNA genes in genomes. It supports bacteria (5S,23S,16S), archaea (5S,5.8S,23S,16S), mitochondria (12S,16S) and eukaryotes (5S,5.8S,28S,18S).

It takes FASTA DNA sequence as input, and write GFF3 as output. It uses the new NHMMER tool that comes with HMMER 3.1 for HMM searching in RNA:DNA style. NHMMER binaries for 64-bit Linux and Mac OS X are included and will be auto-detected. Multithreading is supported and one can expect roughly linear speed-ups with more CPUs.

Address of the bookmark: https://github.com/tseemann/barrnap

iSeqQC: a tool for expression-based quality control in RNA sequencing

BioStar — Sun, 16 Feb 2020 08:47:17 -0600

iSeqQC, an expression-based QC tool that detects outliers either produced due to variable laboratory conditions or due to dissimilarity within a phenotypic group. iSeqQC implements various statistical approaches including unsupervised clustering, agglomerative hierarchical clustering and correlation coefficients to provide insight into outliers.

http://cancerwebpa.jefferson.edu/iSeqQC/

https://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-020-3399-8

Address of the bookmark: https://github.com/gkumar09/iSeqQC

IVA: accurate de novo assembly of RNA virus genomes

Neel — Wed, 23 Jun 2021 07:51:59 -0500

IVA (Iterative Virus Assembler) designed specifically for read pairs sequenced at highly variable depth from RNA virus samples. We tested IVA on datasets from 140 sequenced samples from human immunodeficiency virus-1 or influenza-virus-infected people and demonstrated that IVA outperforms all other virus de novo assemblers.

Availability and implementation: The software runs under Linux, has the GPLv3 licence and is freely available from http://sanger-pathogens.github.io/iva

https://pubmed.ncbi.nlm.nih.gov/25725497/

Address of the bookmark: https://github.com/sanger-pathogens/iva

Understanding RNA-Seq Normalization Methods: TPM vs. FPKM vs. CPM

Neel — Wed, 11 Dec 2024 00:59:15 -0600

RNA sequencing (RNA-Seq) is a powerful technology used to study transcriptomes, providing insights into gene expression levels. However, raw RNA-Seq data requires normalization to account for sequencing depth and gene length, enabling accurate comparisons between genes and samples. Among the most widely used normalization methods are TPM (Transcripts Per Million), FPKM (Fragments Per Kilobase Million), and CPM (Counts Per Million). Each method has its unique principles and applications, which we’ll explore in this blog.

Why Normalize RNA-Seq Data?

Normalization is a crucial step in RNA-Seq analysis for the following reasons:

Sequencing depth: Different RNA-Seq experiments produce varying numbers of reads, making direct comparisons between samples misleading.
Gene length: Longer genes inherently generate more reads, irrespective of their actual expression level.
Bias reduction: Normalization mitigates technical biases, enabling meaningful biological interpretation.

TPM (Transcripts Per Million)

TPM measures the proportion of reads mapped to a transcript, normalized by transcript length and sequencing depth. It is calculated as:

Key Features:

Proportionality: TPM values sum to 1,000,000 across all transcripts in a sample, making it easier to compare between samples.
Intuitive interpretation: TPM values directly represent the abundance of transcripts in a sample.
Preferred for comparisons: TPM facilitates between-sample comparisons better than FPKM.

FPKM (Fragments Per Kilobase Million)

FPKM normalizes read counts by transcript length and sequencing depth, but without enforcing proportionality like TPM. It is defined as:

Key Features:

Historical significance: FPKM was one of the first normalization methods used for RNA-Seq.
Single-end vs. paired-end: In paired-end sequencing, FPKM becomes RPKM (Reads Per Kilobase Million).
Limited utility: FPKM values are not as robust as TPM for cross-sample comparisons due to lack of proportionality.

CPM (Counts Per Million)

CPM normalizes raw read counts by sequencing depth, without considering gene length. It is expressed as:

Key Features:

Simplicity: CPM is straightforward and computationally less intensive.
Application: Suitable for non-length-dependent analyses, such as comparing total expression levels or differential expression analysis.
Gene length agnostic: CPM does not correct for gene length, making it less ideal for measuring expression levels.

When to Use Each Method

TPM: Best for comparing expression levels between samples, especially when transcript length and sequencing depth vary.
FPKM: Useful for historical consistency but generally replaced by TPM.
CPM: Ideal for differential expression analysis when gene length normalization is unnecessary.

Conclusion

Choosing the right normalization method depends on the specific objectives of your RNA-Seq analysis. TPM’s proportionality and robustness make it the preferred choice for most applications, while CPM serves well for differential expression studies. Although FPKM paved the way for RNA-Seq normalization, it has largely been supplanted by TPM in modern workflows. Understanding these methods and their nuances ensures accurate and meaningful interpretations of RNA-Seq data.

References:

Li, B., & Dewey, C. N. (2011). RSEM: accurate transcript quantification from RNA-Seq data with or without a reference genome. BMC Bioinformatics.
Trapnell, C., et al. (2010). Transcript assembly and quantification by RNA-Seq reveals unannotated transcripts and isoform switching during cell differentiation. Nature Biotechnology.
Law, C. W., et al. (2014). voom: precision weights unlock linear model analysis tools for RNA-seq read counts. Genome Biology.

Genetic Test in India

Rahul Agarwal — Sun, 11 Aug 2013 10:54:35 -0500

1.Xcode Life Sciences Pvt. Ltd.
6B, Eldorado,
112, Nungambakkam High Road,
Nungambakkam, Chennai 600034
Tamil Nadu, India

2.Mapmygenome™
Royal Demeure,HUDA Techno Enclave,
Plot No. 12/2, Sector-1 500 081
Madhapur,Hyderabad
AP, India

3. DNA Labs India

http://www.dnalabsindia.com/lab.php

4.MedGenome Labs Pvt Ltd
(Division of SciGenom Labs Pvt Ltd.)
Plot no: 43A,SDF, 3rd floor
A Block,CSEZ, Kakanad, Cochin
Kerala - 682037
Phone: 0484 - 2413399
Fax: 0484 - 2413398
Email: info@medgenome.com

5.Narayana Nethralaya

Narayana Hrudayalaya Campus
Narayana Health City
# 258/A, Bommasandra, Hosur Road,
Bangalore - 560 099 - INDIA.
TEL: +91-80-66660655-0658
FAX: +91-80-66660650
Mobile: 9902 821128 (Emergency Only)
e-mail: info@narayananethralaya.com

6.BioAxis DNA Research Centre Private Limited
13-51,Sri Lakshmi Nagar colony,
Besides Big Bazar, Near Kamineni Hospitals
GSI Post BandalGuda (L B Nagar) Hydeabad-500068
Andhra Pradesh (India).
Phone : +91-40-24034503/+91-9246338983

7.Gene Guiide

8th Floor, Embassy Towers, 7 Bungalows Rd, Versova, Andheri West, Mumbai-61
09167 117799
info@geneguiide.com

See more at: http://www.geneguiide.com

8.INDIAN BIOSCIENCES
Regd. Office:
G-2 (Ground Floor Rear), Kailash Colony, New Delhi - 110048, India.
Phone: +91 (0)11 29236088, Email: info@inbdna.com.

9.SRL Limited

GP-26, MARUTI INDUSTRIAL ESTATE,

UDYOG VIHAR,SECTOR-18,

GURGAON - 122015

Tel: 0124-3001243 / 0124-3001209

SRL Limited
VASANT VIHAR, 8, PALAM MARG,
NEW DELHI - 110057
Tel: 011 - 4229 5333

Website: http://www.srlworld.com
National Customer care number:
Call Toll Free : 1800-222-660/1800-102-8282
E-mail id: customercare@srl.in

10.Tata Memorial Centre,

Advanced Centre for Treatment, Research and Education in Cancer

Kharghar, Navi Mumbai - 410 210, INDIA.

Tel: +91-22-2740 5000

Fax: +91-22-2740 5085

E-mail: mail@actrec.gov.in