Media Clips - EMBL

Scientific American: The 1 Percent Genome Solution
June 13, 2007
The 1 Percent Genome Solution
Tiny slice of genome reveals bustling activity in the gaps between genes
The first results from a massive project to exhaustively catalogue all
the functions of the human genome reveal a hotbed of activity in the
gaps between genes. An international consortium of researchers
sifted through 1 percent of the genome looking for pieces of DNA that
are copied by the cell or help to control gene activity. The results
indicate that most DNA is copied into molecules of RNA, including the
long stretches between genes, and that genes overlap and interact
with each other much more than researchers previously believed.
"We all suspected there was interesting stuff going on in these regions
[between genes], and sure enough there is," says bioinformatician
Ewan Birney of the European Bioinformatics Institute near Cambridge,
England, a member of the project's computer analysis team.
Although researchers do not yet know the biological significance of
these discoveries, they say that fully cataloguing the genome may
help them understand how genetic variations affect the risk of
contracting diseases such as cancer as well as how humans grow
from a single-celled embryo into an adult. The next phase of the
project, set to begin later this year, will attempt to inventory the full
genome.
A genome consists of only four different nucleotide bases, or DNA
subunits, arranged in a particular sequence. The publication of the
human genome in 2001 revealed its sequence—the significance of
which remains a mystery. In particular, genes account for only 1.2
percent of the genome's three billion bases. Once dismissed as "junk
DNA," researchers have found that some of these so-called
noncoding regions are shared among mammals, suggesting they play
an important function.
To help uncover those functions and identify other important
sequences, 35 research groups joined forces in 2003 to create the
encyclopedia of DNA elements (ENCODE) project. This consortium
selected 44 separate sections of the genome that included regions of
high to low gene density and high to low similarity between mouse
and human.
Like treasure hunters combing a vast beach with metal detectors,
ENCODE researchers sifted through their patch of the genome in
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