Fruit fly's genetic blueprint decoded

The insect, a common fruit fly that feeds on fungus, may seem like an obscure animal to study. But scientists say the new genetic achievement will advance research in cancer, the immune system and many other biological processes.

Decoding the blueprint "is the beginning, not the end," said Craig Venter, head of the genetics company Celera Genomics in Rockville, Md.

Celera, along with scientists from the University of California at Berkeley and the Baylor College of Medicine in Houston, collaborated on the project.

Celera and Berkeley researchers reported on the blueprint in Washington on Friday at the annual meeting of the American Association for the Advancement of Science. Scientific papers describing the work are being considered for publication in the association's journal Science.

Since the mid-1990s, researchers have steadily completed the decoding of genetic blueprints for many organisms. Scientists started with simple microbes and worked their way up to yeast, then a worm, and now the fruit fly Drosophila melanogaster.

Celera and scientists funded by the federal government are working separately to complete the human genetic blueprint. The federally funded scientists have said a "rough draft" of the human blueprint will be complete sometime this spring. Knowing the complete set of genetic instructions for a human has been touted as the first step in a new brand of medicine for the 21st century, where scientists can devise more sophisticated medical treatments and tailor them to patients' individual genetic makeups.

The genetic blueprint of the fruit fly is written in 120 million "letters" of DNA code. The researchers started gathering the DNA data a year ago, and then used powerful computers to organize and analyze the information.

A small amount of the genetic blueprint may never be known, said Dr. Gerald Rubin, the biologist who headed the fruit fly research at Berkeley, because it's difficult to analyze in the lab. But the meat of the blueprint consists of portions called genes - the instruments of heredity. Researchers focused on the genes that contain instructions for building proteins, which perform most of the crucial functions of any organism's cells.

And more than 99 percent of the genes are now in publicly available databases on the World Wide Web, Dr. Rubin said. Fruit flies appear to have about 14,000 genes; humans are estimated to have 70,000 to 80,000.

Studies of fruit fly genes have already led to discoveries about people. The set of genes that controls where the antennae, legs and wings sprout on the fly is similar to the set of genes that seem to control where arms, legs and digits grow on people.

And 70 percent of genes known to be involved in growth of cancerous tumors in people are also present in the fly.

"Flies do get cancer," Dr. Rubin said.

The Celera scientists hope to apply the decoding strategy used for the fruit fly on the human genetic blueprint. The federally funded scientists are taking a different approach and have predicted that Celera will have to rely on their data to paint an accurate picture of the human blueprint.