ENCODE PROJECT website http://www.genome.gov/10005107
"Scientists have created the first comprehensive view of how human DNA works. And they say it will rewrite the textbooks and give valuable new insights into the biology of what goes wrong in disease.
"Scientists have created the first comprehensive view of how human DNA works. And they say it will rewrite the textbooks and give valuable new insights into the biology of what goes wrong in disease.
The new work reveals complicated systems for controlling where and when our genes are active.
The research also shows that at least 80 percent of our DNA is actively participating in biological processes. That's far more than just the 2 percent occupied by our genes. Researchers said the extent of that activity was a surprise.
The findings, reported Wednesday by more than 500 scientists, reveal extraordinarily complex networks that tell our genes what to do and when, with millions of on-off switches.
"It's this incredible choreography going on, of a modest number of genes and an immense number of ... switches that are choreographing how those genes are used," said Dr. Eric Green, director of the National Human Genome Research Institute, which organized the project.
The work also shows that at least 80 percent of the human genetic code, or genome, is active. That's surprisingly high and a sharp contrast to the idea that the vast majority of our DNA is junk.
"The big surprise is just how much activity there is," he said. "It's a jungle."
The trove of findings was released in 30 papers published by three scientific journals, while related papers appear in some other journals. In all, the 30 papers involved more than 500 authors. The project is called ENCODE, for Encyclopedia of DNA Elements.
The human genome is made up of about 3 billion "letters" along strands that make up the familiar double helix structure of DNA. Particular sequences of these letters form genes, which tell cells how to make proteins. People have about 20,000 genes, but the vast majority of DNA lies outside of genes.
So what is it doing? In recent years, scientists have uncovered uses for some of that DNA, so it was clearly not all junk, but overall it has remained a mystery.
Scientists found that at least three-quarters of the genome is involved in making RNA, a chemical cousin of DNA. Within genes, making RNA is a first step toward creating a protein, but that's not how it's used across most of the genome. Instead, it appears to help regulate gene activity.
Scientists also mapped more than 4 million sites where proteins bind to DNA to regulate genetic function, sort of like a switch. "We are finding way more switches than we were expecting," Birney said.
Still, "it's worth reminding ourselves that we are very, very complex machines," Birney said. "It shouldn't be so surprising that the instruction manual is really pretty fearsomely complicated." AP
I will praise thee; for I am fearfully and wonderfully made:
Psalm 139:14