1. RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
2. Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
3. Rocky Mountain Laboratory, Microscopy Unit, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA