An international research consortium, called ENCODE The ENCyclopedia Of DNA Elements published the findings four-year effort to build a “parts list” of all biologically functional elements in 1 percent of the human genome in the journal Nature.

According to those findings the human genome isn’t just a collection of genes, but a network in which genes, regulatory elements and other types of DNA sequences interact in complex, overlapping ways.

“By integrating 200 datasets generated by various high-throughput methods we now have a very good idea what 1 percent of our DNA might be doing. Our results reveal important principles about the organization of functional elements in the human genome, providing new perspectives on everything from DNA transcription to mammalian evolution. In particular, we gained significant insight into DNA sequences that do not encode proteins, which we knew very little about before,” said Ewan Birney, Ph.D., head of genome annotation at EMBL-EBI, who led ENCODE’s massive data integration and analysis effort.

The ENCODE consortium’s also discovered that the majority of human DNA is transcribed into RNA and that these transcripts extensively overlap one another. This broad pattern of transcription challenges the long-standing view that the human genome consists of a small set of discrete genes, along with a vast amount of “junk” DNA that is not biologically active. The new data indicate that the genome contains very little unused sequences; genes are just one of many types of DNA sequences that have a functional impact.

“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,” said NHGRI Director Francis S. Collins, M.D., Ph.D.