Human Genome Project Marks 10th Anniversary

This month marks the 10-year anniversary of the Human Genome Project, a 13-year international effort to determine the sequence of the 3 billion "letters" in a human being's DNA.

The $3 billion project, led by the U.S. Department of Energy and the National Institutes of Health, began in 1990 and was completed on April 14, 2003. In the decade since then, scientists have achieved many important milestones in using genomic discoveries to advance medical knowledge.

Sequencing technology has vastly improved in recent years. Sequencing the first human genome cost about $1 billion and took 13 years to complete; today it costs about $3,000 to $5000 and takes just one to two days.

Probing genome function

But just knowing the sequence would be meaningless without a way to interpret it. So researchers found ways to study the genomes function, by sequencing the genomes of 135 other organisms and surveying the global variation among human genomes. [Unraveling the Human Genome: 6 Molecular Milestones]

Researchers compared the genome sequences of other animals, such as chimpanzees and platypuses, as well as other eurkaryotic organisms (those whose cells have a nucleus), such as yeast and flat worms. From this comparison, scientists could identify stretches of DNA that have remained largely unchanged over the course of evolution. Five to 8 percent of the human genome has been unchanged for thousands of years.

One of the more surprising findings is how little of the human genome (only 1.5 percent) actually encodes proteins, the molecular building blocks that perform most of the critical functions inside cells.

To probe this mystery, more than 400 researchers from 32 labs worldwide created the ENCyclopedia Of DNA Element (ENCODE) consortium. In 2012, they published many important findings about how the human genome functions. These include locations in the genome that may be genetic "switches" to turn genes on and off, as well as demonstrating that more than 80 percent of the genome that was once called "junk DNA" actually does serve a function.

Other research has focused on measuring the variation among human genomes. Preliminary studies during the Human Genome Project indicated that human genomes differ by just one-tenth of a percent. Investigating the limited variation that does exist is key to understanding human health and disease.

In sickness and in health

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Human Genome Project Marks 10th Anniversary