1. Wisconsin National Primate Research Center, University of Wisconsin—Madison, Madison, Wisconsin 53715
2. Department of Pathology and Laboratory Medicine, University of Wisconsin—Madison, Madison, Wisconsin 53715
3. Basic Research Program, Laboratory of Genomic Diversity, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702
4. and AIDS Vaccine Program/Basic Research Program, Science Applications International Corporation-Fredrick, Frederick, Maryland 21072