BOL: Related items

GenBank release 257.0 is now available!

Neel — Wed, 23 Aug 2023 00:23:23 -0500

GenBank release 257.0 is now available! This release has 25.10 trillion bases and 3.69 billion records. Learn more: https://ncbiinsights.ncbi.nlm.nih.gov/2023/08/21/genbank-release-257/

GenBank release 257.0 (8/15/2023) is now available on the NCBI FTP site. This release has 25.10 trillion bases and 3.69 billion records.

The current release has:

246,119,175 traditional records containing 2,112,058,517,945 base pairs of sequence data
2,631,493,489 WGS records containing 22,294,446,104,543 base pairs of sequence data
686,271,945 bulk-oriented TSA records containing 646,176,166,908 base pairs of sequence data
124,421,006 bulk-oriented TLS records containing 48,289,699,026 base pairs of sequence data

Genome Origami

Jitendra Narayan — Fri, 12 Dec 2014 22:48:17 -0600

There are several interesting factoid about our genomes, one of them is their folding. If we stretched out the DNA in a single cell, which is only a few millionths of an inch wide, it would span more than six feet. In other word, the size of six feet DNA fold themself to fit in a few millionths of an inch wide space. These DNA folding is a dynamic process that changes over time (!!). Researchers around the world have been trying to understand how DNA folds itself up so efficiently, and a recent post on the NIH Director’s Blog highlights new research illustrating how the human genome folds inside the cell’s nucleus, as well as how DNA folding affects gene regulation. The research team created this delightful video that demonstrates the principles involved using origami art.

http://bioinformaticsonline.com/videolist/watch/19555/a-3d-map-of-the-human-genome

Researchers have been working to determine how cells regulate gene expression for nearly as long as we’ve known about DNA. How, for example, do nerve cells know to turn off only nerve cell genes and turn off bone cell genes? DNA folding loops are part of the answer. This research team, which published their findings in a paper in Cell http://www.cell.com/cell/abstract/S0092-8674%2814%2901497-4 , found that the number of loops is much lower than expected. There are only 10,000 loops instead of the predicted millions, and they form on/off switches in DNA.

More at http://www.eurekalert.org/pub_releases/2014-12/ru-3mr121114.php

Reference http://www.cell.com/cell/abstract/S0092-8674%2814%2901497-4

Entire Human Genome Sequencing !

LEGE — Tue, 02 Apr 2024 01:19:29 -0500

Cost-effective whole human genome sequencing has revolutionized the landscape of genetic research and personalized medicine by making comprehensive genetic analysis accessible to a wider population. Through advancements in sequencing technologies, such as next-generation sequencing (NGS), costs have significantly decreased, enabling researchers and healthcare providers to analyze an individual's complete genetic makeup with greater efficiency and affordability. This has profound implications for disease diagnosis, prognosis, and treatment, as it allows for the identification of genetic predispositions and the customization of healthcare interventions based on an individual's unique genetic profile. Moreover, as the cost continues to decline, the potential for population-scale genomic studies and large-scale screening programs becomes increasingly feasible, promising to further enhance our understanding of human genetics and improve healthcare outcomes on a global scale.

Here are few companies:

https://mynucleus.com/

https://myome.com/

https://nebula.org/whole-genome-sequencing-dna-test/

TRRUST v2: an expanded reference database of human and mouse transcriptional regulatory interactions

Rahul Agarwal — Thu, 21 Dec 2017 17:01:44 -0600

TRRUST contains 8,444 and 6,552 TF-target regulatory relationships of 800 human TFs and 828 mouse TFs, respectively. They have been derived from 11,237 pubmed articles, which describe small-scale experimental studies of transcriptional regulations. To efficiently search for regulatory relationships from over 20 million pubmed articles, we used sentence-based text mining approach.

TRRUST database also provides information of mode of regulation (activation or repression). Currently 8,972 (59.8%) regulatory relationships are known for mode of regulation.

Search at : http://www.grnpedia.org/trrust/Network_search_form.php

Address of the bookmark: http://www.grnpedia.org/trrust/

5700 year-old human genome !

Jit — Thu, 19 Dec 2019 11:22:18 -0600

A Landmark in genomics, scientists have done something that hasn't been done ever.

Scientists have reconstructed the genome of an ancient human who lived nearly 5,700 years ago in Southern Denmark from the birch pitch- an ancient tar-like substance.

By sequencing the sample, researchers not only discovered the ancient human DNA but also microbial DNA reflecting the oral microbiome of the person who chewed the pitch, along with plant and animal DNA that could be the recent meal she might have consumed.

The DNA sample is comparable in quality to well-preserved teeth and skull bones. The DNA suggests that the chewer was a female, most likely with dark skin, dark brown hair and blue eyes.

https://www.nature.com/articles/s41467-019-13549-9

Artistic reconstruction. (Tom Björklund)

More at https://gizmodo.com/scientists-reconstruct-lola-after-finding-her-dna-in-1840481633

When Chromosomes Shift: Understanding Chromosome Rearrangement and Human Disease

BioStar — Fri, 11 Apr 2025 01:07:17 -0500

In the vast and complex world of genetics, our chromosomes are like carefully arranged bookshelves — each holding critical information that defines who we are. But what happens when those books are shuffled, inverted, or swapped? The answer lies in a phenomenon known as chromosome rearrangement, a powerful force behind many human diseases, from developmental disorders to cancer.

What Are Chromosome Rearrangements?

Chromosome rearrangements are structural changes that alter the normal configuration of chromosomes. These changes can involve large segments of DNA — from thousands to millions of base pairs — and can occur spontaneously, be inherited, or result from exposure to mutagens (like radiation or chemicals).

Common Types of Rearrangements:

Deletions – Loss of a chromosome segment
Duplications – Repetition of a segment
Inversions – A segment breaks off, flips, and reattaches
Translocations – Segments exchange places between non-homologous chromosomes
Insertions – A segment is inserted into another part of the genome

These changes can disrupt genes directly or affect gene regulation, leading to disease.

How Do Chromosome Rearrangements Cause Disease?

The impact of a rearrangement depends on which genes are involved, how much DNA is affected, and when the rearrangement occurs (in development vs. adulthood). Here are some key mechanisms:

Gene disruption: Breaking a gene can lead to loss of function or the creation of a non-functional protein.
Gene fusion: Joining parts of two genes may form a novel hybrid gene with new functions (common in cancer).
Dosage effects: Extra or missing gene copies can disturb the balance of gene expression.
Position effects: Moving a gene to a new regulatory environment may silence or over-activate it.

Chromosome Rearrangements in Human Disease

1. Developmental Disorders

Cri-du-chat syndrome: Caused by a deletion on chromosome 5p. Affected infants often have a high-pitched cry and intellectual disability.
Williams syndrome: Results from a microdeletion on chromosome 7q, affecting genes related to cardiovascular and cognitive function.

2. Cancer

Cancer is perhaps the most striking example of disease caused by chromosome rearrangements.

Chronic Myeloid Leukemia (CML): Caused by a translocation between chromosomes 9 and 22, forming the Philadelphia chromosome. This creates the BCR-ABL fusion gene, which drives uncontrolled cell growth.
Burkitt lymphoma: Involves translocation of the MYC gene, leading to excessive cell division.
Ewing sarcoma: A fusion of EWSR1 and FLI1 genes through translocation promotes tumor development.

3. Infertility and Miscarriages

Balanced rearrangements (like inversions or translocations) in carriers may not cause disease directly but can result in:

Recurrent miscarriages
Infertility
Birth defects in offspring

Detecting Rearrangements

Thanks to modern genomics, chromosome rearrangements can now be detected with high precision using:

Karyotyping – Classic method for detecting large rearrangements
FISH (Fluorescence In Situ Hybridization) – Uses fluorescent probes to target specific DNA sequences
Array CGH (Comparative Genomic Hybridization) – Detects copy number changes across the genome
Whole Genome Sequencing (WGS) – Identifies even small or complex rearrangements at base-pair resolution

Looking Forward: The Future of Chromosome Medicine

Understanding chromosome rearrangements is now central to:

Personalized medicine
Genetic counseling
Targeted therapies, especially in cancer (e.g., tyrosine kinase inhibitors for BCR-ABL fusion)

With the rise of long-read sequencing and single-cell genomics, even previously “invisible” rearrangements are being uncovered, offering new insights into both rare diseases and common conditions.

Final Thoughts

Chromosome rearrangements remind us that genetics isn't just about which genes we have — but where they are, how they're arranged, and when they're active. As our tools grow sharper, so does our ability to diagnose, understand, and treat diseases rooted in genomic architecture.

In a way, the genome is like a book not just defined by its words, but also by how the chapters are ordered. Rearranging them can create a new story — sometimes harmful, sometimes insightful — and understanding these changes is key to writing a healthier future.

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

ChopStitch: exon annotation and splice graph construction using transcriptome assembly and whole genome sequencing data

Rahul Nayak — Tue, 03 Jul 2018 04:14:52 -0500

ChopStitch is a new method for finding putative exons and constructing splice graphs using an assembled transcriptome and whole genome shotgun sequencing (WGSS) data. ChopStitch identifies exon-exon boundaries in de novo assembled RNA-seq data with the help of a Bloom filter that represents the k-mer spectrum of WGSS reads. The algorithm also detects base substitutions in transcript sequences corresponding to sequencing or assembly errors, haplotype variations, or putative RNA editing events. The primary output of our tool is a FASTA file containing putative exons. Further, exon edges are interrogated for alternative exon-exon boundaries to detect transcript isoforms, which are reported as splice graphs in dot output format.

Address of the bookmark: https://github.com/bcgsc/ChopStitch

Published a dataset of 363 genomes from approximately 92 percent of bird families

Jit — Thu, 19 Nov 2020 07:04:41 -0600

A research team published a dataset of 363 genomes from approximately 92 percent of bird families and showed the significance of sampling dense organisms for biodiversity research. The study was jointly conducted by Chinese and international institutions and museums and was led by researchers from the Kunming Institute of Zoology (KIZ) of the Chinese Academy of Sciences (CAS). Total of 267 were newly published among the 363 sequenced genomes. They were mainly taken from samples of avian tissue kept in museums around the world, enabling researchers to sequence rare and endangered birds' genomes.

Its descendants have adapted to a wide variety of ecological niches since the first bird formed more than 150 million years ago, giving rise to small, hovering hummingbirds, plunge-diving pelicans and showy paradise birds. More than 10,000 bird species live on the planet today - and now scientists are well on their way to capturing a full genetic image of that diversity.

B10K is expanding its efforts to encompass the next stage of avian classification with 363 genomes complete. The team will sequence thousands of extra genomes in this process, attempting to represent each of the approximately 2,300 bird genera.

The genomic resource is expected to provide new insights on evolutionary processes in cross-species comparative studies and assist in efforts to protect species, according to the research findings reported as a cover story in the journal Nature.

Ref at Dense sampling of bird diversity increases power of comparative genomics https://www.nature.com/articles/s41586-020-2873-9

Phased Human Genome Assembly !

Rahul Nayak — Mon, 08 Oct 2018 09:10:54 -0500

The new publicly available assembly (PacBio HG00733) has the fewest gaps of any human genome assembly, with more than half of the genome contained in gapless sequence at least 27 Mb long. The primary contig assembly is 2.89 Gb long and consists of 865 contigs that were assembled with PacBio data generated with the company’s Sequel® System. Using the FALCON-Unzip assembler, maternal and paternal haplotypes were resolved over more than 80% of the genome. Maternal and paternal haplotype blocks were then further phased using Hi-C technology and the FALCON-Phase methoddeveloped in collaboration with Phase Genomics. The genome was then de novo scaffolded using Phase Genomics’ Proximo Hi-C platform, resulting in the first chromosome-scale diploid assembly of a single individual accomplished with only two technologies. More specific details about the assembly are included on the PacBio blog.

The data are available using NCBI accession IDs: BioProject: (PRJNA483067), assembly: [RBJD00000000] and sequence data (SRP155659).

Additional Resources

Interactive map showcasing global initiatives underway to generate reference-quality human genome assemblies for diverse populations
BioReport Podcast on the value of ethnic-specific reference genomes
Nature Reviews Genetics paper from NHGRI: Prioritizing diversity in human genomics research
Article in The Journal of Precision Medicine: “Minority Report – Ethnic Diversity and the Real Promise for Precision Medicine”
Article in Bio-IT World: “Genomic Data Standards Are a Necessity”
NHGRI Project Award: High Quality Human and Non-Human Primate Genome Assemblies

More details are available on the PacBio website:

Blog post: Data Release: Highest-Quality, Most Contiguous Individual Human Genome Assembly to Date
Blog post: For Reference-Grade Human Genome Assemblies, SMRT Sequencing Yields Optimal Results
Webinar: Assembling High-Quality Human Reference Genomes for Global Populations
FALCON-Phase press release and article preprint
PacBio research focus webpage about Human Population Genetics

Ref: https://stockguru.com/2018/10/08/pacific-biosciences-releases-highest-quality-most-contiguous-individual-human-genome-assembly-to-date/