Biologists theorize role for DNA packaging in stem cell development

Nov 06, 2008

MIT biologists have discovered that the organization of DNA's packing material plays a critical role in directing stem cells to become different types of adult cells.

The work, to be published in the journal Cell on Nov. 14, could also shed light on the possible role of DNA packaging in cancer development.

Led by Laurie Boyer, assistant professor of biology at MIT, the researchers examined the role of chromatin — the structure that forms when DNA is wound around a core of proteins called histones.

"We're particularly interested in how chromatin structure influences gene expression and ultimately cell fate," Boyer said. "We hope the studies we are doing can lead to better understanding of development as well as certain diseases."

It has been theorized that cancer cells may overexpress genes involved in early embryonic development, allowing them to proliferate unchecked and regress from adult tissue cells to a stem cell-like state.

Such regression could be partly mediated by changes in chromatin. This packaging is believed to help control DNA transcription because the more tightly wound the chromatin is, the less accessible DNA is to be transcribed.

The new study focused on a variant type of histone known as H2AZ, which other researchers have recently identified as a protein of interest in cancer.

While H2AZ is ubiquitously expressed in many cell types including adult cells, it is known to be essential for normal embryonic development. The new research reveals why: The variant histones are found near the promoter regions of a particular set of genes that are important for development.

The same genes are also regulated by a group of proteins known as Polycomb group (PcG) proteins, which act as gene silencers.

"It suggests that this histone variant — along with the Polycomb group proteins — may act as some kind of regulatory switch that mediates cell fate transitions," Boyer said. "We hypothesize that they're working together, and that allows these genes to be silent yet poised for activation in stem cells."

In future studies, Boyer's team plans to look at patterns of H2AZ distribution in cancerous cells.

Source: Massachusetts Institute of Technology

Explore further: Nest-building in finches is a learning process developed through experience

add to favorites email to friend print save as pdf

Related Stories

Rainbow trout genome sequenced

Apr 22, 2014

Using fish bred at Washington State University, an international team of researchers has mapped the genetic profile of the rainbow trout, a versatile salmonid whose relatively recent genetic history opens ...

Rapid and accurate mRNA detection in plant tissues

Apr 17, 2014

Gene expression is the process whereby the genetic information of DNA is used to manufacture functional products, such as proteins, which have numerous different functions in living organisms. Messenger RNA (mRNA) serves ...

Gene removal could have implications beyond plant science

Apr 16, 2014

(Phys.org) —For thousands of years humans have been tinkering with plant genetics, even when they didn't realize that is what they were doing, in an effort to make stronger, healthier crops that endured climates better, ...

Recommended for you

Genome yields insights into golden eagle vision, smell

10 hours ago

Purdue and West Virginia University researchers are the first to sequence the genome of the golden eagle, providing a bird's-eye view of eagle features that could lead to more effective conservation strategies.

Genetic code of the deadly tsetse fly unraveled

11 hours ago

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Ocean microbes display remarkable genetic diversity

11 hours ago

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...

Engineered E. coli produces high levels of D-ribose

12 hours ago

D-ribose is a commercially important sugar used as a sweetener, a nutritional supplement, and as a starting compound for synthesizing riboflavin and several antiviral drugs. Genetic engineering of Escherichia co ...

User comments : 0

More news stories

Genetic code of the deadly tsetse fly unraveled

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals.

Ocean microbes display remarkable genetic diversity

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live i ...

Cell resiliency surprises scientists

New research shows that cells are more resilient in taking care of their DNA than scientists originally thought. Even when missing critical components, cells can adapt and make copies of their DNA in an alternative ...