Scientists reveal mechanism that triggers differentiation of embryo cells
December 22, 2008The mechanism whereby embryonic cells stop being flexible and turn into more mature cells that can develop into specific tissues has been discovered by scientists at the Hebrew University of Jerusalem. The discovery has significant consequences towards furthering research that will eventually make possible medical cell replacement therapy based on the use of embryonic cells.
At a very early stage of human development, all cells of the embryo are identical, but unlike adult cells are very flexible and carry within them the potential to become any tissue type, whether it be muscle, skin, liver or brain.
This cell differentiation process begins at about the time that the embryo settles into the uterus. In terms of the inner workings of the cell, this involves two main control mechanisms. On the one hand, the genes that keep the embryo in their fully potent state are turned off, and at the same time, tissue-specific genes are turned on. By activating a certain set of genes, the embryo can make muscle cells. By turning on a different set, these same immature cells can become liver. Other gene sets are responsible for additional tissues.
In a recent paper, published in the journal, Nature Structural and Molecular Biology, Professors Yehudit Bergman and Howard Cedar of the Hebrew University-Hadassah Medical School have deciphered the mechanism whereby embryonic cells stop being flexible and turn into more mature cells that can differentiate into specific tissues. Bergman is the Morley Goldblatt Professor of Cancer Research and Experimental Medicine and Cedar is the Harry and Helen L. Brenner Professor of Molecular Biology at the Medical School.
They found in their experiments, using embryos from laboratory mice and cells that grow in culture, that this entire process is actually controlled by a single gene, called G9a, which itself is capable of directing a whole program of changes that involves turning off a large set of genes so that they remain locked for the entire lifetime of the organism, thereby unable to activate any further cell flexibility.
Their studies shed light not only on this central process, but also can have consequences for medical treatment. One of the biggest challenges today is to generate new tissues for replacing damaged cells in a variety of different diseases, such as Parkinson's disease or diabetes. Many efforts have been aimed at "reprogramming" readily-available adult cells, but scientists have discovered that it is almost impossible to do this, mainly because normal tissues are locked in their fixed program and have lost their ability to convert back to fully potent, flexible, embryonic cells.
Now, with the new information discovered by Bergman and Cedar, the molecular program that is responsible for turning off cell flexibility has been identified, and this may clear the way towards developing new approaches to program cells in a controlled and specific manner.
Source: The Hebrew University of Jerusalem
-
Scientists use an old theory to discover new targets in the fight against breast cancer
Feb 07, 2012 |
5 / 5 (2) |
0
-
Weightlessness weighs heavy on genes -- a fly's perspective
Jan 31, 2012 |
3.5 / 5 (2) |
0
-
Researchers turn skin cells into neural precusors, bypassing stem-cell stage
Jan 30, 2012 |
5 / 5 (2) |
4
-
Patterns of chromosome abnormality: The key to cancer?
Jan 23, 2012 |
not rated yet |
0
-
Study: Stem cells may aid vision in blind people
Jan 23, 2012 |
4.7 / 5 (15) |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
More news stories
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
13 hours ago |
4.4 / 5 (20) |
0
|
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...
13 hours ago |
5 / 5 (4) |
0
|
The proteins ensuring genome protection
Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...
13 hours ago |
5 / 5 (3) |
0
|
Entire genome of extinct human decoded from fossil
(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...
Feb 07, 2012 |
4.7 / 5 (60) |
51
|
Why are there so few fish in the Earth's oceans?
(PhysOrg.com) -- A Stony Brook University researcher has found that, contrary to popular belief, there are not plenty of fish in the sea.
Feb 08, 2012 |
4.3 / 5 (19) |
27
|
Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy
For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...
New method to examine batteries -- MRI from the inside
There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...
Google might launch Drive for cloud storage soon
(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV
A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...
Iran blocks email, restricts net access: reports
Iran has further restricted access to the Internet and blocked popular email services for the past few days, in a move a top lawmaker said could "cost the regime dearly," media reports said on Sunday.