A new report on a set of genes discovered which contribute to a form of heart disease is less interesting for the discovery than for the tools developed which made the discovery possible. Development of a much cheaper and very sensitive technique for measuring message RNA expression levels enabled the discovery.
The one-gene, one-disease concept is elegant, but incomplete. A single gene mutation can cause many other genes to start—or stop—working, and it may be these changes that ultimately cause clinical symptoms. Identifying the complete set of affected genes used to appear impossible. Not anymore.
Studying genetically modified mice, researchers led by Christine E. Seidman, a Howard Hughes Medical Institute investigator at Brigham and Women's Hospital, and her husband Jonathan G. Seidman, who is at Harvard Medical School, have identified hundreds of genes with altered expression in preclinical hypertrophic cardiomyopathy. The study, which is coauthored by colleagues at Harvard Medical School, is published in the June 9, 2007, issue of the journal Science. The discovery could help scientists define the pathways that lead to the disease and lead to the discovery of targets for early detection, prevention, and treatment.
A new technique provides a highly sensitive way of measuring gene expression levels.
To obtain a complete picture of the genetic changes associated with the disease, the researchers developed a new gene sequencing technique called polony multiplex analysis of gene expression, or PMAGE. The technique can find messenger RNA transcripts—the directions for making a protein, spun out from the DNA of an active gene—that occur as rarely as one copy for every three cells.
PMAGE drops costs by an order of magnitude.
The industry standard for gene sequencing is serial active gene expression, or SAGE. "There are a couple of labs that have been dedicated to developing this technology," Seidman said, including HHMI investigator Bert Vogelstein at Johns Hopkins and George Church at Harvard. But PMAGE analysis costs between 1/20 and 1/9 of a comparable SAGE analysis, making it more appropriate for the kind of large-scale expression profiling undertaken in this study, she explained. "With SAGE, you can't afford to sequence 4 million transcripts."
These order of magnitude cost drops in assorted techniques for measuring genetic sequences and gene expression levels just keep coming. As the costs of measurement and data collection keep falling the rate at which scientists figure out what genes do keeps accelerating.
Many more order of magnitude cost drops for genetics and molecular biology lay in store in the future. A coming enormous flood of discoveries enabled by biotechnological advances will sweep through and revolutionize medicine.
|Share |||Randall Parker, 2007 June 11 11:56 PM Biotech Advance Rates|