1. Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403
2. Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403
3. Institute of Human Genetics, University of Würzburg, D-97074 Würzburg, Germany
4. The Genome Institute, Washington University School of Medicine, St. Louis, Missouri 63108
5. Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas 78666
6. Physiological Chemistry, University of Würzburg, Biozentrum, Am Hubland, and Comprehensive Cancer Center, University Clinic Würzburg, 97074 Würzburg, Germany