Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Short-Term Gene-Expression "Memory" is Inherited in Proteins Associated with DNA, New Research Finds

07.08.2013
By studying a gene in yeast, a team of scientists has found that modifications to histones -- proteins associated with DNA -- can control whether or not a gene is allowed to function and may be important in maintaining the genes' "expression potential" so that future cells behave as their parent cells did.

The research was led by Lu Bai, an assistant professor of biochemistry, molecular biology, and physics at Penn State University, in collaboration with David Stillman at the University of Utah. The discovery, which may have implications for the study of diseases such as cancer, will be published in a print edition of the journal Proceedings of the National Academy of Sciences.


Three fluorescent images of yeast cells as they grow from two single cells (left) to a small cell cluster (right). The green color represents the expression of the HO gene. The red color at the bud neck is a marker for cell cycle.

Credit: Bai lab, Penn State University

Bai explained that gene expression -- the process by which certain genes are regulated or turned "on" or "off" -- is one of the most fundamental processes in the life of any biological cell. Different programs of gene expression -- even when cells have the same DNA -- can lead to different cellular behavior and function. For example, even though a human muscle cell and a human nerve cell have identical DNA, they behave and function very differently.

Misregulation of gene expression can affect cell fitness and lead to diseases. "Gene expression tends to vary from cell to cell," Bai said. "Misregulation may happen in a small fraction of cells, and these cells may cause disease later on. Therefore it is important to study gene regulation at the single-cell level."

Using a fluorescent video of cell division, Bai and her team were able to observe how a gene called HO was expressed in single yeast cells over multiple cell divisions. Normally, the expression of HO allows budding yeast to change sex -- from "male" to "female" and vice versa. "Interestingly, HO expression -- and thus sex change -- is supposed to occur only in 'mother' cells but not the newly budded 'daughter' cells," Bai explained.

After observing the video, team members found that HO was expressed in 98 percent of the mother cells but also in 3 percent of the daughter cells. "The vast majority of both the mother cells and the daughter cells responded as they were supposed to," Bai said. "But, in a small percentage of the cells, the gene regulation went wrong."

The pressing question for Bai's team then was, why did the HO gene regulation fail in a small population of cells -- in 2 percent of the mother cells and 3 percent of the daughter cells? She discovered that the answer seems to lie in histones, a major protein complex associated with DNA. "We found that changes in histone configurations affect the fraction of cells in which the HO expression was misregulated.

In addition, we found that, in some conditions, the HO expression can 'remember' itself: If HO is turned on in one cell, it is more likely to be turned on in its progeny cells. We showed that this short-term memory of the HO expression seems to be inherited through histone modifications," Bai said. She added that further study of gene expression, specifically at the level of individual cells, can have important implications for disease research.

In addition to Bai and Stillman, other researchers who contributed to this study include Qian Zhang, Youngdae Yoona, Juan Antonio Raygoza Garay, and Michael M. Mwangi from Penn State; Yaxin Yu and Emily J. Parnell from the University of Utah; and Frederick R. Cross from the Rockefeller University.

The research was funded by the National Institutes of Health.

Barbara K. Kennedy | EurekAlert!
Further information:
http://www.psu.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>