About the Authors

Ian G Woods

Affiliation Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America

William S Talbot

To whom correspondence should be addressed. E-mail: talbot@cmgm.stanford.edu

Affiliation Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

IGW and WST conceived and designed the experiments. IGW performed the experiments. IGW and WST analyzed the data and wrote the paper.