Yuanchao Xue1,2, Runsheng Chen3,4, Lianghu Qu5, Xiaofeng Cao6,7. 1. Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. 2. University of Chinese Academy of Sciences, Beijing, 100049, China. 3. Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. rschen@ibp.ac.cn. 4. University of Chinese Academy of Sciences, Beijing, 100049, China. rschen@ibp.ac.cn. 5. MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China. lssqlh@mail.sysu.edu.cn. 6. State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China. xfcao@genetics.ac.cn. 7. University of Chinese Academy of Sciences, Beijing, 100049, China. xfcao@genetics.ac.cn.