1. State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
2. State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
3. Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China.
4. Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA.
5. Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA.