Patent ID: 8202718

Claim:
A polynucleotide sequence encoding a gene switch comprising: (a) a first gene expression cassette comprising a polynucleotide sequence that encodes a first polypeptide comprising an ecdysone receptor ligand binding domain; and (b) a second gene expression cassette comprising a polynucleotide sequence that encodes a second polypeptide comprising a nuclear receptor ligand binding domain, wherein one of the first gene expression cassette or the second gene expression cassette comprises a DNA-binding domain that recognizes a response element associated with a gene of interest, wherein the first gene expression cassette or the second gene expression cassette that does not comprise the DNA-binding domain comprises a transactivation domain, wherein the ligand binding domain in the first polypeptide and the ligand binding domain in the second polypeptide are different and dimerize, wherein at least one of the first polypeptide and the second polypeptide does not contain the A and B domains of the corresponding ecdysone receptor or nuclear receptor ligand binding domain that is not an ultraspiracle ligand binding domain, wherein the gene switch is more sensitive to a diacylhydrazine ligand than to a steroid ligand, and wherein the gene that is expressed is a component of a chimeric gene comprising: (i) a response element to which the DNA-binding domain binds; (ii) a promoter that is activated by the transactivation domain; and (iii) the gene that is expressed.