Toronto, Dec 15 (IANS): Biologists at the University of Toronto have discovered an on-off switch for a stem cell gene that is critical for early development.

The discovery could mean a significant advance in the emerging field of human regenerative medicine, as the Sox2 gene is essential for maintaining embryonic stem cells that can develop into any mature animal cell.

"We studied how the Sox2 gene is turned on in mice and found the region of the genome that is needed to turn the gene on in embryonic stem cells," said professor Jennifer Mitchell from the University of Toronto's department of cell and systems biology in Canada.

Like the gene itself, this region of the genome enables these stem cells to maintain their ability to become any type of cell, a property known as pluripotency.

"We named the region of the genome that we discovered as the Sox2 control region or SCR," Mitchell added.

The sequencing of the human genome was completed in 2003. Since then, researchers have been trying to figure out which parts of the genome made some people more likely to develop certain diseases.

They found that the answers are more often in the regions of the human genome that turn genes on and off.

These parts of the human genome are linked to complex diseases such as heart disease, cancer and neurological disorders.

The paper was published in the journal Genes & Development.