Media Clips - EMBL

FT.com print article
Research reveals complexity in how human genes
interact
By Clive Cookson in London
Published: June 14 2007 03:00 | Last updated: June 14 2007 03:00
The first thorough examination of how the human genome works, published today, has overthrown
the traditional view of our genetic blueprint as a collection of independent genes floating in an
ocean of "junk DNA".
Instead, the 3bn chemical "letters" of the human genetic blueprint form an extremely complex
network in which genes, regulatory elements and other DNA sequences interact in overlapping
ways that are not yet understood.
The new view of the genome appears in 29 scientific papers published simultaneously in the
journals Nature and Genome Research. It comes from a $42m (€31m, £23m) international project
called the Encyclopedia of DNA elements (Encode) consortium, led by the US National Human
Genome Research Institute with the Wellcome Trust and the European Bioinformatics Institute.
Francis Collins, NHGRI director, called the results"a landmark in molecular biology". He said: "This
impressive effort has uncovered many exciting surprises and blazed the way for future efforts to
explore the functional landscape of the entire human genome."
Conventional genes - stretches of DNA coding for proteins, the molecules that do almost all the
biochemical work in living creatures - make up only 2 per cent of the human genome. Even with the
separate control and regulatory regions of the genome that are responsible for switching
conventional genes on and off, no more than 10 per cent of human DNA is made of such clear-cut
functional elements. Until now, many biologists have regarded the majority of the genome as "junk
DNA" carried from generation to generation but with no biological function.
The Encode project analysed in great depth a representative 1 per cent of the genome (30m letters
of DNA). This showed that most human DNA is biologically active, rather than being pure junk
DNA.
The purpose of all this transcribed genomic information remains unclear. Some of it represents a
more sophisticated control system for conventional genes; the new work identifies many previously
unknown regulatory regions and shows that control regions may be in quite different areas of the
genome from the genes they affect. This could complicate efforts to treat diseases.
Other parts of the genome may represent a previously unsuspected evolutionary reserve - not
doing much at the moment but potentially useful for the future.
Dr Collins provided an analogy: "It is like the clutter in the attic of your house, which you don't get
rid of, in case you ever need it," he said.
"Most of the time, the genome is acting on the first and second floors but over evolutionary time
[millions of years] theclutter in the attic may be useful."
Comparisons show that many of these regions are not shared with other species but are restricted
to the human genome - a potential source of new variation.
Copyright The Financial Times Limited 2007
BUSINESS LIFE
SCIENCE & ENVIRONMENT
http://www.ft.com/cms/s/194fd592-1a14-11dc-99c5-000b5df10621,dwp_uuid=df2...
Page 1 of 2
Close
6/14/2007