Article History

Received: 6 October 2016

Accepted: 16 February 2017

First Online: 3 April 2017

Change Date: 24 April 2017

Change Type: Erratum

Change Details: This Article should have been published under a Creative Commons licence according to the Nature policy on publishing the primary sequence of an organism's genome for the first time. The manuscript is now open access and published under a CC-BY licence. All versions of the Article have been modified accordingly.

Change Date: 25 August 2017

Change Type: Correction

Change Details: In Fig. 5 of the version of this Article originally published, the final number on the <i>x</i> axes of each panel was incorrectly written as 1.5; it should have read 7.5. This has now been corrected in all versions of the Article.

Competing interests

: The authors declare no competing financial interests.