New evidence that stem cells contain immortal DNA

June 27, 2006

EuroStemCell scientists at the Pasteur Institute in Paris have demonstrated one of the body’s most sophisticated ways of regulating the genetic material of stem cells. Their findings, published in Nature Cell Biology, show for the first time the mechanism that adult muscle stem cells use to protect their DNA from mutations. Understanding this has important implications for cancer research, the study of gene regulation, and ultimately growing stem cells of therapeutic potential in the laboratory.

When a cell divides, its DNA is duplicated and each resulting daughter cell inherits one copy of the DNA. Over time, errors arising during the duplication process can lead to mutations and cause cancers. Using sophisticated approaches including video imaging the Pasteur team show that stem cells retain the original DNA strands. Their findings also represent the best visual evidence yet for immortal DNA - a controversial theory first proposed more than 3 decades ago.

A stem cell can produce two different daughter cells when it divides in the body – another stem cell and a specialised cell that will contribute to the tissue. This is called “asymmetric division” and helps stem cells regulate their numbers and retain their capacity to regenerate tissue throughout the life of an organism. According to the immortal DNA hypothesis, when a stem cell divides, only the specialised cell inherits the imperfect copied DNA. The stem cell retains the original “immortal” DNA strand.

Leading the Pasteur team, Shahragim Tajbakhsh says “the immortal DNA theory has captured the imagination of many scientists for decades, but it has been particularly difficult to prove. By tracking skeletal muscle stem cells from mouse muscle fibres, both in vivo and in the dish, we have shown that the DNA strands of the double helix are not equivalent, and we have linked this phenomenon with the general asymmetry apparatus of the dividing cell.”

He adds “this is an exciting finding, as it seems to defy one of the basic rules of cell biology and genetics: that genetic material is distributed randomly. It appears that the cellular machinery distinguishes old from new when it comes to DNA, and it may use this distinction to protect the body from mutations and cancer. It is also possible that this mechanism is used to silence gene expression in the stem cell.”

Source: EuroStemCell (the European Consortium for Stem Cell Research)

Explore further: Scientists home in on origin of human, chimpanzee facial differences

Related Stories

Researchers develop a method for controlling gene activation

September 8, 2015

Researchers at the University of Helsinki, Finland, have developed a new method which enables the activation of genes in a cell without changing the genome. Applications of the method include directing the differentiation ...

Dually noted: New CRISPR-Cas9 strategy edits genes two ways

September 7, 2015

The CRISPR-Cas9 system has been in the limelight mainly as a revolutionary genome engineering tool used to modify specific gene sequences within the vast sea of an organism's DNA. Cas9, a naturally occurring protein in the ...

Recommended for you

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

Internet giants race to faster mobile news apps

October 4, 2015

US tech giants are turning to the news in their competition for mobile users, developing new, faster ways to deliver content, but the benefits for struggling media outlets remain unclear.

Trade in invasive plants is blossoming

October 3, 2015

Every day, hundreds of different plant species—many of them listed as invasive—are traded online worldwide on auction platforms. This exacerbates the problem of uncontrollable biological invasions.

Fusion reactors 'economically viable' say experts

October 2, 2015

Fusion reactors could become an economically viable means of generating electricity within a few decades, and policy makers should start planning to build them as a replacement for conventional nuclear power stations, according ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.