1. Howard Hughes Medical Institute and Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
2. Medical Scientist Training Program, University of California, San Diego (UCSD), 9500 Gilman Drive, La Jolla, CA 92037, USA.
3. Biomedical Sciences Graduate Program, UCSD, 9500 Gilman Drive, La Jolla, CA 92037, USA.
4. Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
5. Neurosciences Graduate Program, UCSD, 9500 Gilman Drive, La Jolla, CA 92037, USA.
6. Biological Sciences Graduate Program, UCSD, 9500 Gilman Drive, La Jolla, CA 92037, USA.
7. Peptide Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.