Until recently, microbiologists were elated when the genome of their favorite bug was sequenced. Now the emerging gold standard is to compare multiple genomes of one species. The Institute for Genomic Research (TIGR) in Rockville, Maryland, wants to take anthrax to this level. TIGR plans to sequence as many as 20 strains of Bacillus anthracis from around the world--three times more than have been sequenced for any other species.
Having a wide range of anthrax genomes could help investigators nab future bioterrorists and aid in designing drugs and vaccines; comparing them should also reveal why some strains are more virulent than others, or why some are better at surviving in the soil, says anthrax researcher Martin Hugh-Jones of Louisiana State University, Baton Rouge. Charting the genetic diversity of many strains is also fascinating in its own right, adds TIGR director Claire Fraser. "It's something that we've wanted to do for a very long time, and it has nothing to do with the biodefense issue." The strains will be selected by Paul Keim, an anthrax geneticist at Northern Arizona University in Flagstaff, who is involved in the criminal investigation of last fall's attacks (Science, 30 November 2001, p.1810). Keim has come up with a list of candidate strains that he says best represents anthrax's diversity. After the first four genomes are complete, TIGR and the funder, the National Institute of Allergy and Infectious Diseases, will review the project to see how useful the information turns out to be. At the current price of about $150,000 per genome, the project could cost $3 million.
TIGR has already sequenced two B. anthracis genomes. One, a lab strain called Ames, has been in the works for several years, and the last gaps should be filled within weeks, TIGR's Timothy Read reported last week at the Second Conference on Microbial Genomes in Las Vegas. The institute has also determined the draft sequence of what is now known as the Florida strain: the anthrax that killed a photo editor in Boca Raton last October. Although that microbe, too, belongs to the Ames strain, TIGR says subtle differences set it apart from the first one--differences that may help identify the perpetrators of the attacks.