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