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T. Whipplei s a Wolf, Say Sequencers

NEW YORK, Feb 20 - A lead sequencer of the genome for tiny gut microbe T. Whipplei said the team's work, to be published in The Lancet Feb. 22, unmasks a bacterial "wolf in sheep's clothing."

 

"Within this amazingly small genome, it has packed a sophisticated array of tools to escape our defence mechanisms,"  said Stephen Bentley, who led the team at The Wellcome Trust Sanger Institute that was sequencing this bacterium,  in a statement. "It's an incredibly adept operator which can tell us a great deal about bacteria and their evolution."

 

Along with colleagues at StanfordMedicalCenter, the Universityof Birmingham in the UK, and The University of Heidelberg, the Sanger scientists sequenced the 925,938 base pairs of T. Whipplei, and predicted 784 genes.   They found that the genome appears to splice new sections into the genes that encode coat proteins, in order to change this coat to adapt to its environment. The organism also will steal protein coats from its host.

 

This genome, less than a third the size of those from most sequenced bacteria, was of particular interest because T. Whipplei lives in humans, is responsible for a human disease, and yet remains poorly understood.

 

Whipple's disease has symptoms that range from acute abdominal pain and diarrhea to heart disease or neurological disease in the advanced state. These symptoms were first described by noted American pathologist George Whipple in 1907, but the organism, which lives in the lining of the gut, was not seen under microscopy until 1961.

 

Until recently,  T. Whipplei remained an enigma because it has been nearly impossible to culture. In fact, the sequencers spent longer trying to grow the bacteria for the T. Whipplei genome project than they did sequencing it, according to the Wellcome Trust.

 

But with the sequence of this organism in hand, T. Whipplei whizzes may be able to answer some long-unsolved mysteries about its functions and life cycle.

 

"The genome is our finest microscope to study this remarkable organism," stated Axel von Herbay, one of the sequencers from the Universityof Heidelberg.

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