2 genome rivals team up in a friendly rat race

Celera, Baylor work to sequence rodent

March 01, 2001|By Julie Bell | Julie Bell,SUN STAFF

Rivals in the sometimes acrimonious race to sequence the human genome are working together to unravel the genomic software powering the rat, an animal often used as a model to help understand disease in people, the National Institutes of Health announced yesterday.

Celera Genomics Group, which recently published its human genome sequence in the journal Science, and the Baylor College of Medicine, a key sequencing center for the rival publicly funded project that published in Nature, have been awarded two new grants totaling $58.5 million to help sequence the rat.

The awards, $21 million of which will go to Celera over the next two fiscal years, are meant to speed up a publicly funded rat DNA-sequencing project begun at the end of the 1999 fiscal year. The additional money was awarded by the National Heart, Lung and Blood Institute and the National Human Genome Research Institute, the NIH agency that has overseen the publicly funded project.

"I was told Celera applied for it and they measured up," Research Institute spokesman Geoff Spencer said of how Celera was chosen. "It was as simple as that."

Neither Francis Collins, head of the publicly funded project, nor Celera President J. Craig Venter could be reached for comment yesterday. But the two were more than civil earlier last month as they sat next to each other at a joint press conference announcing the Science and Nature publications. At one point, Collins even threw his arm around Venter, proclaiming, "We're buddies."

In a statement yesterday, Venter said Celera was pleased to be involved in the project. The rat genome, he said, is a model that "should aid researchers in their quest for a better understanding of basic human biology and health and thus to find improved cures and treatments for disease."

Doug Smith, a sequencing expert for Waltham, Mass.-based Genome Therapeutics Corp., another company collaborating to sequence that rat, said yesterday that Celera's inclusion in a public project shows that things "have evolved to a different level." What's more, the former rivals - who once sparred publicly about whose DNA-sequencing approach was better - will be using a combination of the two approaches to unravel the genome of the rat.

"Certainly, they're no longer rivals because they're part of the same project," Smith said. "That speaks for itself."

The scientists will be attempting to string together, in order, all the DNA necessary to build and power a rat. The recipe, like that of the human genome, will look something like a long computer program made up of chemical "bases" represented by the letters A, C, T and G. Stretches of those letters along the genome make up genes, which act much like microbiological software as they direct proteins to go about the work of running the body.

To assemble the human genome, Celera used an approach known as the whole genome shotgun method, which involved chopping up the genome into tiny bits, putting the bits in a giant pile and running them through powerful sequencing machines to reassemble them in order. The publicly funded project, however, used a different method that involved first breaking the 3-billion-plus base pairs of the genome into smaller sections, cutting them up into even smaller pieces and then putting them back together a section at a time.

To assemble the rat genome, Baylor, Genome Therapeutics Corp. and Celera will use the shotgun-sequencing method to compile large numbers of sequencing "reads." To assemble them, they then will make use of landmarks from map data developed by the University of British Columbia, Baylor and the Rockville-based Institute for Genomic Research, headed by Venter's wife, Claire Fraser.

The NIH said a draft of the rat sequence, estimated to be similar in size to the human genome at 3 billion base pairs, will be complete in two years.

Howard Jacob, director of the Laboratory for Genetic Research at the Human Molecular Genetics Center in Milwaukee and a self-described "torch-bearer" for sequencing the rat, said scientists soon will be able to overlay the mouse, human and rat genomes to assess where they diverge, highlighting areas for further study.

"Important genes are conserved through evolution and so similar versions are found in different animal species," said George Weinstock, co-director of the Baylor Human Genome Sequencing Center.

"The similarities between human DNA and the DNA of other living organisms are a critical guide to help researchers find genes that function similarly in humans. These model systems give us great hints for understanding human biology."

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