The study by scientists at The Institute for Genomic Research (TIGR) and collaborators at Baylor College of Medicine and the University of Texas Health Science Center at Houston found profound differences between the gene content of T. denticola, which is associated with periodontal (gum) disease, and of other spirochetes that cause syphilis and Lyme disease.

"This highlights the power of comparative genomics to help us understand how related pathogens can cause completely different diseases," says Ian Paulsen, who led the sequencing along with fellow TIGR researcher Rekha Seshadri. Paulsen says the T. denticola genome "provides an excellent point of reference to study the biology of spirochetes."

The paper will appear in the April 13, 2004 issue of Proceedings of the National Academy of Sciences (PNAS) and was scheduled to be published online this week. The study was supported by the National Institute of Dental and Craniofacial Research (NIDCR), which is part of the U.S. National Institutes of Health.

The researchers found that T. denticola has more than twice as many genes as the spirochete that causes syphilis, T. pallidum, and that there is virtually no conservation of gene order (synteny) between the genomes of the two related microbes. The authors say that indicates that the two spirochetes' divergence from a common ancestor "was an ancient event" in contrast to the more recent divergence of many other groups of bacteria from their ancestral relatives.

The genome study is expected to help scientists find out more about how oral pathogens interact in dental plaque to cause gum disease. T. denticola tends to aggregate in such subgingival plaque wi
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Contact: Robert Koenig
rkoenig@tigr.org
301-795-7880
The Institute for Genomic Research
29-Mar-2004