College;
of;
Life;
Sciences,;
Peking;
University,;
Beijing;
100871,;
China;
College;
of;
Life;
Sciences,;
Peking;
University,;
Beijing;
100871,;
China;
College;
of;
Life;
Sciences,;
Peking;
University,;
Beijing;
100871,;
China;
cell-free; system,; nuclear; reconstitution,; Orychophragmus; violaceus,; demembranated; sperm,; Xenopus; laevis,; egg; extracts.;