1. Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
2. Department of Biological Sciences, Columbia University, New York, New York 10027
3. School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112
4. Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706
5. Human Genome Sequencing Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas 77030