Featured Research

from universities, journals, and other organizations

Developmental on-switch: Substances that convert body cells back into stem cells initially activate all genes in the embryo

Date:
August 16, 2013
Source:
Albert-Ludwigs-Universität Freiburg
Summary:
Researchers have demonstrated for the first time why the molecular cocktail responsible for generating stem cells works. Sox2 and Oct4 are proteins whose effect on cells resembles that of an eraser: They remove all of the cell’s previous experiences and transform it into a so-called pluripotent stem cell. Like cells in the embryo, this stem cell can then develop into all forms of tissue.

The Pou5f1 protein acts as an on-switch for embryonic development in zebrafish.
Credit: © Wolfgang Driever

Substances that convert body cells back into stem cells initially activate all genes in the embryo.

Freiburg researchers have demonstrated for the first time why the molecular cocktail responsible for generating stem cells works. Sox2 and Oct4 are proteins whose effect on cells resembles that of an eraser: They remove all of the cell's previous experiences and transform it into a so-called pluripotent stem cell. Like cells in the embryo, this stem cell can then develop into all forms of tissue. The discoverers of this reprogramming technique received the Nobel Prize in Physiology or Medicine in 2012. However, until now scientists did not understand precisely why these proteins can reprogram cells and what function they have in the embryo.

A team from the Department of Developmental Biology and the Cluster of Excellence BIOSS Centre for Biological Signalling Studies, led by Dr. Daria Onichtchouk and Prof. Dr. Wolfgang Driever, has discovered that the Oct4 protein in the zebrafish embryo, which is initially provided by the mother, is responsible for switching on the embryo's genes for the first time, thus initiating the animal's independent development. Young embryonic cells can develop into all tissues and cell types found in the body, just like cultures of the so-called pluripotent stem cells. These multi-talented cells are the focus of much attention in biomedical research because experts hope to use them to regenerate damaged organs without having to resort to embryonic stem cells.

In an article published in the journal Science, the Freiburg scientists explain that the zebrafish Pou5f1 protein, which is very similar to the human Oct4 protein, serves as the main starting signal for embryonic development. Pou5f1 awakens the genes after the resting period following fertilization. In all animals, development is initially controlled by proteins from the mother in the egg cell; the genes of the embryo are not activated until some time later. In the zebrafish, for instance, this process is triggered as soon as the embryo has a thousand cells. This "zygotic gene activation" reprograms the cells of the embryo: Specialized, rapidly dividing cells that do not create any new gene products become stem cells. These embryo stem cells can form all cell types -- like pluripotent stem cells. In the case of so-called mesodermal cells, which can form blood or muscles, the scientists demonstrate how the Pou5f1 protein sets off the cascade of gene products that create muscle, blood, or bone cells from the embryonic cells. This regulatory network is very similar to that of the pluripotent stem cells.

Researchers have been able to generate pluripotent stem cells for several years now, but have found it difficult to convert them into stable cell types with sufficient reliability -- if stem cells are unstable, they can become cancerous. Using the regulatory network discovered in the zebrafish, developmental biologists can now study how particular cell types in the body are created from stem cells and what makes them stable. Scientists require reliable processes for forming stable tissue before it can be used for applications in medicine.


Story Source:

The above story is based on materials provided by Albert-Ludwigs-Universität Freiburg. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Leichsenring, J. Maes, R. Mossner, W. Driever, D. Onichtchouk. Pou5f1 Transcription Factor Controls Zygotic Gene Activation In Vertebrates. Science, 2013; DOI: 10.1126/science.1242527

Cite This Page:

Albert-Ludwigs-Universität Freiburg. "Developmental on-switch: Substances that convert body cells back into stem cells initially activate all genes in the embryo." ScienceDaily. ScienceDaily, 16 August 2013. <www.sciencedaily.com/releases/2013/08/130816094708.htm>.
Albert-Ludwigs-Universität Freiburg. (2013, August 16). Developmental on-switch: Substances that convert body cells back into stem cells initially activate all genes in the embryo. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2013/08/130816094708.htm
Albert-Ludwigs-Universität Freiburg. "Developmental on-switch: Substances that convert body cells back into stem cells initially activate all genes in the embryo." ScienceDaily. www.sciencedaily.com/releases/2013/08/130816094708.htm (accessed September 20, 2014).

Share This



More Plants & Animals News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) — Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) — A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
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:
from the past week

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