About the Authors
Biology Department, Lund University, Lund, Sweden
Biology Department, Duke University, Durham, North Carolina, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: TN. Performed the experiments: TN. Analyzed the data: TN YLG. Contributed reagents/materials/analysis tools: TN YLG EJW. Wrote the paper: TN YLG EJW.