About the Authors

Michael E Hurwitz

Affiliations Howard Hughes Medical Institute (HHMI), Department of Biology, MIT, Cambridge, Massachusetts, United States of America , Massachusetts General Hospital Cancer Center, Boston, Massachusetts, United States of America

Pamela J Vanderzalm

Current address: Department Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois, United States of America

Affiliation Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America

Laird Bloom

Current address: Wyeth Pharmaceuticals, Biological Technologies Department, Cambridge, Massachusetts, United States of America

Affiliation Howard Hughes Medical Institute (HHMI), Department of Biology, MIT, Cambridge, Massachusetts, United States of America

Julia Goldman

Affiliation Howard Hughes Medical Institute (HHMI), Department of Biology, MIT, Cambridge, Massachusetts, United States of America

Gian Garriga

Affiliations Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America , Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America

H. Robert Horvitz

To whom correspondence should be addressed. E-mail: horvitz@mit.edu

Affiliation Howard Hughes Medical Institute (HHMI), Department of Biology, MIT, Cambridge, Massachusetts, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

MEH, PJV, LB, GG, and HRH conceived and designed the experiments. MEH, PJV, LB, and JG performed the experiments. MEH, PJV, LB, GG, and HRH analyzed the data. MEH, PJV, GG, and HRH wrote the paper.