1. Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
2. Department of Land Resources and Environmental Sciences, Montana State University, Post Office Box 173120, Bozeman, MT 59717–3120, USA.
3. The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA.
4. Department of Biology, University of Southern California, Wrigley Marine Science Center, Post Office Box 5069, Avalon, CA 90704, USA.