May 18, 2008 Before West Nile virus arrived in this country, we
had (and still have) a home-grown relative of this pathogen. An
epidemic of unknown origin exploded around St. Louis, Missouri
in the autumn of 1933, a disease that is now known to be
transmitted by mosquitoes from birds to people. Now, a new
analysis of the genome of St. Louis encephalitis completed at
the Sackler Institute for Comparative Genomics at the American
Museum of Natural History (AMNH) is shedding light on the
evolution of this virus. Under the direction of Susan Perkins,
Assistant Curator of Microbial Genomics, postdoctoral fellows
Gregory Baillie, Sergios-Orestis Kolokotronis, and Eric Waltari
sequenced the entire genetic code of 23 strains of the virus
that cause St. Louis encephalitis, all from the genus
Flavivirus. Previous research had found that recombination (the
cutting and pasting of strands of genetic material, in this case
RNA) explained the evolution of this virus, but these studies
sequenced just a single gene of the vir