Nature Cell Biol. 12, 341–350 (2010); published online 21 March 2010; corrected after print, 26 March 2010

In the version of this article initially published online and in print, there was an error in the numbering of authors who contributed equally. The corrected numbering should be as follows:

Boris Guirao1,2,7, Alice Meunier1,7, Mireille Montcouquiol6,8, Kazunobu Sawamoto3,8 and Nathalie Spassky1,9

7,8These authors contributed equally to this work.

9Correspondence should be addressed to N.S. (e-mail: spassky@biologie.ens.fr)

This error has been corrected in both the HTML and PDF versions of the article.