Featured Research

from universities, journals, and other organizations

Scientists Switch Gene Expression On And Off In Neurons

Date:
June 21, 2007
Source:
Public Library of Science
Summary:
Genes which had been inactive in neurons during early mouse development can become functionally silenced in the adult brain, according to a new article. Switching gene expression "on" and "off" is of utmost importance when studying gene function in the adult nervous system.

Activators (green) bind to DNA sequences (blue) and turn-on gene expression (arrow, upper panel) in young mice. Under these conditions gene expression continues to remain active in adult mice (right, upper panel). On the other hand, unavailability of the activator in young mice turns-off gene expression (left, lower panel), which subsequently leads to changes in gene accessibility (blue, lower right panel), thus disabling activator-to-DNA binding (lower right panel) with gene expression remaining switched-off.
Credit: Zhu et al.

Genes which had been inactive in neurons during early mouse development become functionally silenced in the adult brain, according to a new article. Our brain consists of billions of nerve cells enabling to learn, remember and reason. Every time we think and experience, touch, smell or fear, millions of neurons in our brain becomes active. These nerve cells communicate with each other by chemical and electrical impulses to compute incoming sensory information and integrate it via distinct brain regions.

With 20,000 - 25,000 genes in our genome, most also expressed in neurons, there is now little doubt that neurons respond to challenging environments by adjusting the expression of genes for appropriate brain functions. Stress, addiction, learning and disease are all believed to change neuronal gene expression by mechanisms involving gene accessibility without changes in DNA sequences, a process called epigenetics ("above and beyond the gene").

Switching gene expression "on" and "off" is of utmost importance when studying gene function in the adult nervous system. In the early 1990s, scientists described a tetracycline-controlled gene expression systems (Tet systems), which allow the regulation of gene expression by externally applied substances.

The Tet-regulated gene expression can be used to analyze involvement of genes for example in cognition in the mouse, as was shown in key studies from 1996. But in spite of the published success, others scientists report some difficulties: in some experiments the full reactivation of Tet-regulated genes failed. Mazahir T. Hasan and colleagues at the Max Planck Institute for Medical Research in Heidelberg have therefore systematically examined individual components of the Tet systems and delineated the necessary conditions for reversible control of gene expression in neurons.

Researchers now report that genes which had been inactive in neurons during early mouse development become functionally silenced in the adult brain. Intriguingly, Hasan and colleagues found that gene silencing in the adult brain can be avoided by making neurons produce high levels of gene-specific activators which facilitate "un-silencing" of previously silenced genes. These findings have important implications in experimental research that makes use of reversible gene expression tools to switch genes on and off.

Neuroscientists need such gene switches to investigate the cause-and-effect relationship between gene activity, neuronal physiology, and animal behavior. Hence, this new research is an important step in both the development of highly reliable gene-switches for experimental neuroscience and in our understanding of mechanisms governing gene regulation in the brain. Indeed, the epigenetic mechanisms in charge of switching genes "on" or "off" play an essential role when our brain learns and stores information, and when our brain reacts to injury and disease.

Citation: Zhu P, Aller MI, Baron U, Cambridge S, Bausen M, et al (2007) Silencing and Un-silencing of Tetracycline-Controlled Genes in Neurons. PLoS ONE 2(6): e533. doi:10.1371/journal.pone.0000533 (http://www.plosone.org/doi/pone.0000533)


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Scientists Switch Gene Expression On And Off In Neurons." ScienceDaily. ScienceDaily, 21 June 2007. <www.sciencedaily.com/releases/2007/06/070620073439.htm>.
Public Library of Science. (2007, June 21). Scientists Switch Gene Expression On And Off In Neurons. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2007/06/070620073439.htm
Public Library of Science. "Scientists Switch Gene Expression On And Off In Neurons." ScienceDaily. www.sciencedaily.com/releases/2007/06/070620073439.htm (accessed October 1, 2014).

Share This



More Health & Medicine News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Positive Ebola News: Outbreak 'Contained' In Nigeria

Some Positive Ebola News: Outbreak 'Contained' In Nigeria

Newsy (Sep. 30, 2014) The CDC says a new case of Ebola has not been reported in Nigeria for more than 21 days, leading to hopes the outbreak might be nearing its end. Video provided by Newsy
Powered by NewsLook.com
UN Ebola Mission Head: Immediate Action Is Crucial

UN Ebola Mission Head: Immediate Action Is Crucial

AFP (Sep. 30, 2014) The newly appointed head of the United Nations Mission for Ebola Emergency Response (UNMEER), Anthony Banbury, outlines operations to tackle the virus. Duration: 00:39 Video provided by AFP
Powered by NewsLook.com
CDC Confirms First Case of Ebola in US

CDC Confirms First Case of Ebola in US

AP (Sep. 30, 2014) The CDC has confirmed the first diagnosed case of Ebola in the United States. The patient is being treated at a Dallas hospital after traveling earlier this month from Liberia. (Sept. 30) Video provided by AP
Powered by NewsLook.com
New Breast Cancer Drug Extends Lives In Clinical Trial

New Breast Cancer Drug Extends Lives In Clinical Trial

Newsy (Sep. 30, 2014) In a clinical trial, breast cancer patients lived an average of 15 months longer when they received new drug Perjeta along with Herceptin. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins