1. Department of Biology, Stanford University, Stanford, CA 94305, USA
2. Small Molecule Mass Spectrometry Facility, Harvard University, Cambridge, MA 02138, USA
3. Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA
4. Centro Jambatu de Investigación y Conservación de Anfibios, Fundación Otonga, San Rafael, Quito, Ecuador
5. Proteomics Mass Spectrometry Facility, Harvard University, Cambridge, MA 02138, USA