1. Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA.
2. Department of Biology, University of Utah, Salt Lake City, UT, USA.
3. Departments of Microbiology and Molecular Genetics and Medicine, University of California, Irvine, Irvine, CA, USA.
4. Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA.
5. Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA, USA.