PROBLEM TO BE SOLVED: To obtain a new vector, for example, for the detection of unknown genes of drosophila by incorporating two sets of expression-controlling sequences consisting of enhancers and promotors of the target sequence of a transcription factor from a yeast, so as to direct them downward mutually appositely. SOLUTION: This is a new vector which is prepared by incorporating, into p element sequence, two sets of expression-controlling sequences consisting of UAS enhancers and promotors which are the target sequences of a transcription factor GAL4 from a yeast, so as to direct them downward mutually appositely, and is useful, for example, for the gene detection method by p element insertion which allows efficient identification, in genome, of unknown new genes, which control various biofunctions of drosophila, in correspondence with their biofunctions. This vector is obtained by incorporating, into p element sequence, two sets of expression-controlling sequences consisting of UAS enhancer of the target sequence of a transcription factor GAL4 and a core promotor of heat shock protein hsp 70 gene from a yeast, so as to direct them downward mutually appositely.
