Scientific Reports 5, Article number: 7645 (2015); Published: 6 January 2015; Updated: 12 March 2015

In this Article, the Author Contributions Statement is duplicated in the Acknowledgements. The Acknowledgements should read:

We thank Dr. Guoliang Xu for providing Tet1 knockout mice. We thank Dr. Zeng-qiang Yuan for valuable comments on the work. This work was supported by the 973 Program (2011CBA00400); Strategic Priority Research Program of the Chinese Academy of Science, Grant No.XDB02050400 to Z.Q.