Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful sequencing technology decodes DNA folding pattern

12.04.2012
Findings provide tools for better understanding of the human genome

hromosomes are strands of DNA that contain the blueprint of all living organisms. Humans have 23 pairs of chromosomes that instruct how genes are regulated during development of the human body. While scientists have developed an understanding of the one-dimensional structure of DNA, until today, little was known about how different parts of DNA are folded next to each other inside the nucleus.

Using a powerful DNA sequencing methodology, researchers at the Ludwig Institute for Cancer Research have now investigated the three-dimensional structure of DNA folds in the nucleus of a chromosome. The findings published in the April 11 issue of Nature provide scientists with a greater understanding about the basic principles of DNA folding and its role in gene regulation.

"In any biology textbook, when you look at a diagram of how genes are depicted, it is invariably a one-dimensional line. In reality, genes are arranged in such a way that two parts of the gene may be distal to each other linearly, but very close in 3-D," said Dr. Bing Ren, Member of the Ludwig Institute for Cancer Research and Professor of Cellular and Molecular Medicine at the University of California, San Diego. "With the knowledge of how DNA folds inside the nucleus, we now have a more complete picture of the regulatory process of genes. That is the primary reason we sought to tackle this problem." The spatial organization is intimately linked to its role in the body.

Ludwig researchers used a sequencing-based method called Hi-C to examine the 3-D structure of chromosomes. "With this technology, we were able to build a map of pair-wise interactions from each chromosome, and from that, extrapolate the basic folding pattern of the DNA. What we learned is that they fold into many local domains termed topological domains, which are on average one million base pairs in size. By way of comparison, the whole human genome is just over three billion base pairs in size," explained lead researcher, Jesse Dixon, a graduate student in Dr. Ren's lab.

In examining the interaction map, Dr. Ren's team discovered that topological domains are the basic unit of folding. The team confirmed their findings by comparing it among different cell types. In each type, the folding of DNA into topological domains was constant.

A parallel study by researchers at Institut Curie and the University of Massachusetts Medical School support Ludwig researchers' findings. By focusing on the mouse X chromosome segment in embryonic stem cells, as well as neuronal cells and fibroblasts, researchers showed that this segment adhered to similar folding patterns as the ones found by Ren's team. They further showed that this organization could be linked to gene regulation.

"This is just the beginning of a very exciting area of research focused on the understanding of nuclear processes from a three-dimensional point of view. We know that some cancers, including many leukemias, are caused by the translocation of two genes. It's not clear how these translocations are regulated or whether they result from random events. It's possible that the spatial structure of the chromosome can provide clues about how these translocations occur and, more importantly, how we can prevent them or at least mitigate their effect," concluded Dr. Ren.

Co-authors on the paper include Siddarth Selvaraj of the Ludwig Institute for Cancer Research and the University of California, San Diego; Feng Yue, Audrey Kim, Yan Li and Yin Shen of the Ludwig Institute for Cancer Research; and Ming Hu and Jun S. Liu of Harvard University. Development of the new Hi-C technique used in the study was pioneered by a team of researchers including Job Dekker, professor and co-director of the Program in Systems Biology at the University of Massachusetts Medical School.

This work was supported by funding from the Ludwig Institute for Cancer Research, the California Institute for Regenerative Medicine, the National Institutes of Health and the Rett Syndrome Research Foundation.

About The Ludwig Institute for Cancer Research

LICR is an international non-profit organization committed to improving the understanding and control of cancer through integrated laboratory and clinical discovery. Leveraging its worldwide network of investigators and the ability to sponsor and conduct its own clinical trials, the Institute is actively engaged in translating its discoveries into applications for patient benefit. Since its establishment in 1971, the Institute has expended more than $1.5 billion on cancer research.

For further information please contact Rachel Steinhardt, rsteinhardt@licr.org or +1-212-450-1582

Rachel Steinhardt | EurekAlert!
Further information:
http://www.licr.org

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>