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.A New Zealand genetics expert has heralded the Encyclopaedia of DNA Elements as a "huge breakthrough".

The ENCODE Project has discovered that so-called "junk DNA" in the human genome is more useful than previously thought. Rather than useless remnants from our evolutionary past, half or more of human DNA act as "gene switches", researchers found.

The findings are the work of more than 500 scientists worldwide and were yesterday released in 30 papers in three journals.

Genes are not always turned "on", director of genetics at Otago University, associate professor Peter Dearden explained. Different genes are turned on in different cells and tissues, making those cells different from one another.

"If you think about all the cell types that are in the human being ... the differences in those different sorts of cells is about what genes are turned on in those cells, what proteins they're making," Dr Dearden said.

"The difference between a liver cell and a kidney cell isn't what's in the genome - it's what bits of the genome are turned on."

Dr Dearden likened the historic 2001 sequencing of the human genome to a "massive library".

"Now what we have got is at least an index of that information, we've got some idea of where those little bits of the genome are which control that information that we discovered in 2001," he said.

Dr Dearden heralded the findings as a "really important breakthrough".

"It's a huge breakthrough - it really makes an enormous difference that we can point to a piece of DNA and say 'well that piece of DNA controls this particular gene and makes sure it is turned on in neural cells or kidney cells or whatever'."

Scientists say the discovery could have massive impact on research on diseases. For example, most of the DNA changes which make cells turn cancerous occurs in the pieces of DNA which control genes - the switches.

While an exciting breakthrough, Dr Dearden said there was still more work to be done in the area.

"We've got this map of where particular elements are in the genome, [but] we still need to understand better what they do and how they do their job.

"It's like another layer of information. The human genome was great, but it didn't tell us everything we need to know. We're now a little bit further along in understanding what it does. There is still more information to find out what it does, how it does that job and why it is important."

For more on the Encode project, Dr Peter Dearden has written a blog about the breakthrough here.




Source:

http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&;objectid=10832430