Patent ID: 7537904

Claim:
An animal cell in vitro expressing a ligand-responsive transcription control factor and stably transformed with a DNA comprising in a molecule, both of the following polynucleotides (a) and (b): (a) a polynucleotide comprising a reporter protein coding region connected functionally downstream from a transcription control region, wherein said transcription control region (a-1) substantially consists of a recognition sequence of said ligand-responsive transcription control factor and a minimum promoter comprising the nucleotide sequence of SEQ ID NO: 5 which can function in said cell, and (a-2) contains no functional elements relating to transcription control in said cell other than the recognition sequence and the minimum promoter; and (b) a polynucleotide comprising a selective marker protein coding region connected functionally downstream of a promoter which can function in said cell, wherein said selective marker protein is a protein which can provide the cell with a resistance against chemicals suppressing or disturbing proliferation of the cell; wherein said ligand-responsive transcription control factor is one selected from among an aryl hydrocarbon receptor, estrogen receptor, androgen receptor and thyroid hormone receptor.