Patent ID: 7183061

Claim:
A method for controlling gene expression in a cell, the method comprising: (a) transforming a cell with a DNA molecule, said DNA molecule comprising a first component which encodes an ecdysone receptor, said receptor comprising: (i) a ligand binding domain of a Heliothis virescens ecdysone steroid receptor as shown in amino acids 327–545 of SEQ ID NO: 5 or a derivative of said ligand binding domain wherein said derivative comprises one or more conservatively substituted amino acids and wherein said derivative retains a function of said ligand binding domain; (ii) a DNA binding domain; and (iii) a transactivation domain; and a second component comprising a hormone response element and a target gene; and (b) applying to the transformed cell an effective exogenous inducer wherein when the ligand binding domain of said first component binds the effective exogenous inducer, said DNA binding domain of said first component then binds to the hormone response element of said second component and causes expression of said target gene.