Theo minh duoc biet, day la phuong phap thay the hoac cai bien mot promoter bang mot promoter khac nhung van giu nguyen trinh tu ma hoa (coding sequence).
Muc dich la de thay doi muc do (tang hoac giam) cach thuc bieu hien cua gene (cam ung hoac thuong truc)
Cach thuc hien: tai to hop tuong dong