1. Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin 53715
2. Laboratory of Genomic Diversity, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702
3. Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53715
4. AIDS Vaccine Program/Basic Research Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland 02172