About the Authors
Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
Department of Biological Structure, University of Washington, Seattle, Washington, United States of America
The authors have declared that no competing interests exist.
CMM, HR, and EB conceived and designed the experiments. CMM and NM performed the experiments. CMM, NM, HR, and EB analyzed the data. CMM, HR, and EB wrote the paper.