Celera closes on genome goal

Celera's approach uses powerful computers

By BBC News Online science editor Dr David Whitehouse

Leading US gene-sequencing company Celera Genomics says it has finished reading the genetic code of one person and is now putting the information together into a meaningful order.

Celera aims to win the race to be the first to have a complete sequence of the human genome, the collection of all the genes and other genetic material that is the basic blueprint of human life.

It is competing with the publicly-funded scientists of the Human Genome Project (HGP) which promises a "working draft" of the "book of life" by June.

Celera plans to survey the genes of five different people, who will remain anonymous, to complete a final human genome sequence. It will copy this sequence several times over to make sure it is correct.

The company says that it now has 99% of one person's genetic sequence in its database.

Rapid progress

Celera only started working on the human genome in September, using a method called whole genome shotgun sequencing. This is a different technique from that used by government-funded scientists in the HGP.

"Now that we have completed the sequencing of one human being's genome, we will turn our computational power to the task of ordering the human genome," Dr Craig Venter, the company's president and chief scientific officer, said in a statement.

"This is expected to allow researchers worldwide and our subscribers to utilise our data to make important medical advances."

Some publicly-funded scientists have accused Celera of failing to keep its promise to make the human genome information widely available. But Celera has said it will release the data.

Jigsaw puzzle

What Celera has done is take the genes and break them apart into two different lengths. It uses standard genetic technology to read out the nucleotides, known by the initials A, C, T and G. These four nucleotides repeat over and over again in varying patterns that make up the genetic code.

This way, Celera has tens of thousands of genetic jigsaw puzzle pieces. To put them into the correct order, it uses the largest and most powerful computer in the world in civilian hands.

One person's genes are not considered enough to tell scientists about the human genome. So Celera plans to use five people in all.

Mark Adams, vice president for genome programmes at Celera, said they were chosen for their diversity. "They are not five white guys," he said in a recent interview.

The Human Genome Project, in contrast, is using a "mosaic" of about 10 different donors. Most of the sequence will come from one person's genes. That person, too, will remain anonymous.

Scientists then hope to compare various people's different genes to find the tiny changes in the code that describe our individuality.

Last month, Celera published the genome of the most complex animal yet sequenced, the fruit fly.