Following transfection, X can be either transiently expressed in undifferentiated cells in the population, or {HEAD ~ P X} can be inheritable and expressed in {TAIL ~ undifferentiated progeny} 
expressed in
Following transfection , X can be either transiently expressed in undifferentiated cells in the population , or { HEAD ~ P X } can be inheritable and expressed in { TAIL ~ undifferentiated progeny }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL