1. University of North Carolina, 2217-B, McGavran-Greenberg Hall, Chapel Hill, NC 27599-7400, USA
2. Institute of Cytology and Genetics of the Russian Academy of Sciences, Lavrentiev Ave. 10, Novosibirsk 630090, Russia
3. Avirid, Inc., 2153 SE Howthorne Road, Suite 10, Gainesville, FL 3261-7553, USA