Institute of Genetics, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai 200433, Peoples Republic of China.|Institute of Genetics, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai 200433, Peoples Republic of China.|Institute of Genetics, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai 200433, Peoples Republic of China.