About the Authors

Xianfeng Ping

Affiliation Center for Quantitative Biology and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China

Chao Tang

tangc@pku.edu.cn

Affiliation Center for Quantitative Biology and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: CT. Performed the experiments: XP. Analyzed the data: XP. Wrote the paper: XP CT. Constructed the model: XP.