About the Authors
Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: ESK DAB. Performed the experiments: ESK NBE. Analyzed the data: ESK. Contributed reagents/materials/analysis tools: ESK DAB. Wrote the paper: ESK DAB.