© 2017 Hou and Witman. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). Publisher PDF posted as allowed by the publisher's author rights policy at http://www.molbiolcell.org/site/misc/ifora.xhtml.
Except where otherwise noted, this item's license is described as © 2017 Hou and Witman. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). Publisher PDF posted as allowed by the publisher's author rights policy at http://www.molbiolcell.org/site/misc/ifora.xhtml.