BEIJING, June 14 (Xinhuanet) -- An in-depth
examination by 35 teams of researchers from 80 different organizations in 11
countries who shared notes on 1 percent of the human genome has revealed there
is no such thing as "junk DNA" and that some of what was considered
"useless-looking" stretches of DNA may rewrite the book on evolution
and causes of some diseases.
Their findings, the start of the Encyclopedia of DNA
Elements or ENCODE Project, were published in the journals Nature and Genome
Research.
"This is a landmark in our understanding of human
biology," said Dr. Francis Collins, head of the National Human Genome Research
Institute, which funded much of the work.
Some scientists were surprised that human beings had
only about 30,000 genes after the human genome was published in 2003. Rice, for
instance, has 50,000. The new study confirms what many genetics experts had
suspected ¡ª the genes are important, but so is the other DNA, the biological
code for every living thing.
What they discovered is that even DNA outside the
genes transcribes information. Transcription is the process that turns DNA into
something useful ¡ª such as a protein.
Much of this action is going on outside the genes in
the so-called regulatory regions that affect how and when a gene activates,
Collins said. The researchers discovered 4,491 of these so-called transcription
start sites, "almost tenfold more than the number of established genes," they
wrote in the Nature paper.
Ewan Birney of the European Molecular Biology
Laboratory's European Bioinformatics Institute in Cambridge said this helped
explain how such a complex creature as a human arose from just four letters of
code repeated over and over.
"The junk is not junk. It is really active," Birney
told reporters. This could be useful in understanding and treating disease.
(Agencies)