Roughly 3 metres of DNA is tightly folded into the nucleus of every cell in our body. This folding allows some genes to be 'expressed', or activated, while excluding others.
Dr Tim Mercer and Professor John Mattick from Sydney's Garvan Institute of Medical Research and Professor John Stamatoyannopoulos from Seattle's University of Washington analysed the genome's 3D structure, at high resolution.
Genes are made up of 'exons' and 'introns' – the former being the sequences that code for protein and are expressed, and the latter being stretches of noncoding DNA in-between. As the genes are copied, or 'transcribed', from DNA into RNA, the intron sequences are cut or 'spliced' out and the remaining exons are strung together to form a sequence that encodes a protein. Depending on which exons are strung together, the same gene can generate different proteins.
Using vast amounts of data from the ENCODE project*, Dr Tim Mercer and colleagues have inferred the folding of the genome, finding that even within a gene, selected exons are easily exposed.
"Imagine a long and immensely convoluted grape vine, its twisted branches presenting some grapes to be plucked easily, while concealing others beyond reach," said Dr Mercer. "At the same time, imagine a lazy fruit picker only picking the grapes within easy reach.
"The same principle applies in the genome. Specific genes and even specific exons, are placed within easy reach by folding."
"Over the last few years, we've been starting to appreciate just how the folding of the genome helps determine how it's expressed and regulated,"
"This study provides the first indication that the three-dimensional structure of the genome can influence the splicing of genes."
"We can infer that the genome is folded in such a way that the promoter region — the sequence that initiates transcription of a gene — is located alongside exons, and they are all presented to transcription machinery."
"This supports a new way of looking at things, one that the genome is folded around transcription machinery, rather than the other way around. Those genes that come in contact with the transcription machinery get transcribed, while those parts which loop away are ignored."
The National Human Genome Research Institute launched a public research consortium named ENCODE, the Encyclopedia Of DNA Elements, in September 2003, to carry out a project to identify all functional elements in the human genome sequence.
Alison Heather | EurekAlert!
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy