Scientist completes the reading of 3 billion pairs of genetics subunits -- subscribe

In October 1990, biologists officially embarked on one of the century’s most ambitious scientific efforts: reading the 3 billion pairs of genetic subunits — the A’s, T’s, C’s and G’s — that make up the human instruction book. The project has been compared to the Manhattan Project to build an atomic bomb and the Apollo missions to land on the moon. The effort promised to blow open our understanding of basic biology, reveal relationships between the myriad forms of life on the planet and transform medicine through insights into genetic diseases and potential cures. When a draft of the instruction book was announced in 2000, the scientists having read essentially every letter, President Bill Clinton called it a “stunning and humbling achievement” and predicted that it would “revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases.”Even dreaming up such an endeavor depended on decades of previous discoveries. Most of our textbook notions of how the information of life is encoded, the details of how it’s passed on and how it makes us who we are, were uncovered during the 20th century. In 1905, English biologist William Bateson, who championed the work of Austrian monk Gregor Mendel, suggested the term genetics for a new field of study focused on heredity and variation. Early the next decade, American biologist Thomas Hunt Morgan and his colleagues showed that genes were carried on chromosomes. Biochemists had been studying DNA for nearly three-quarters of a century when Oswald Avery and his team at the Rockefeller Institute in New York City helped establish in the 1940s that DNA is the genetic material. And perhaps most notable, and famous today, is the 1953 discovery of the double-helix structure of DNA, by James Watson and Francis Crick of University of Cambridge and Rosalind Franklin and Maurice Wilkins of King’s College London.But when the draft instruction book was published, independently by an international collective of academic and government labs called the Human Genome Project and the private company Celera Genomics, led by J. Craig Venter, the text was “as striking for what we don’t see as for what we do,” Science News reported. There were many fewer genes than expected, leaving a puzzle about what all the remaining DNA was for. In the decades since, scientists have filled in some of that puzzle — identifying hosts of genes, for example, that don’t make proteins but are still essential in the body. Other researchers have searched the instruction book to find new treatments for diseases and to figure out how we’re all related — not just people, but all life on planet Earth, past and present.To explore how far our understanding of our DNA has come, Science News senior writer and molecular biology reporter Tina Hesman Saey talked with Eric Green, director of the National Human Genome Research Institute at the National Institutes of Health in Bethesda, Md. Green got his start in genomics in the lab of Maynard Olson at Washington University in St. Louis, a pioneer in the field. At the same time, Saey was a graduate student in molecular genetics working down the hall. She remembers as an undergraduate student sequencing the genes of bacteria 50 to 100 chemical subunits, or bases, at a time. “My mind was completely blown by the idea that you could put together 3 billion bases.” The conversation that follows, which has been edited for length and clarity, looks back on the project and ahead to all that’s left to learn. — Elizabeth Quill