A research team at the National Institute of Standards and Technology (NIST) has provided the first look* at a genetic structure that may play a critical role in the reproduction of the infectious salmon anemia virus (ISAV), more commonly known as the "fish flu." A scourge in fish farms with a mortality rate as high as 90 percent, ISAV was recently found in wild salmon in the Pacific Northwest for the first time, threatening an already dwindling population and the vast food web it supports.
While there is a vaccine for the virus, it must be administered by injectiona task that is both cumbersome and economically impractical for the aquaculture industry. A drug or vaccine that prevents the spread of the disease by interfering with the virus' ability to replicate its genetic code (contained in eight segments of ribonucleic acid or RNA) would be far more practical for fish farmers and marine biologists to deliver.
Robert Brinson, a NIST scientist working at the Hollings Marine Laboratory (HML) in Charleston, S.C., and NIST colleagues Andrea Szakal and John Marino working at the Institute for Bioscience and Biotechnology Research (IBBR) in Rockville, Md., knew from the scientific literature that the family of viruses that includes both the many types of influenzathe causes of yearly human flu outbreaksand infectious salmon anemia, form "panhandle" structures in their genomic RNA. In human influenza, these panhandles are known to interact with proteins that begin the process of copying and replicating the virus.
Hypothesizing that the fish flu virus might function the same way, Brinson and his colleagues used high-resolution nuclear magnetic resonance (NMR) spectroscopy and thermal melting methods to look at the genetic structure in the same region of the ISAV RNA. They found that the ISAV genome does appear to have a panhandle "motif" (the poetic term used by geneticists to define a discrete nucleotide sequence that functions independ
|Contact: Michael E. Newman|
National Institute of Standards and Technology (NIST)