Abstract: The present application provides a vector for trapping an unknown gene of Drosophila melanogaster, which is a recombinant plasmid comprising the following nucleotide sequences in this order: an artificial consensus splicing acceptor site; a synthetic “stop/start” sequence; a reporter gene; a drug resistance gene; a gene responsible for a detectable phenotype of the Drosophila melanogaster; and a synthetic splicing donor site. The present application also provide a method for trapping an unknown gene of Drosophila melanogaster by using the vector.

Abstract: The invention relates to new expression vectors. More particularly, the invention relates to expression vectors carrying a new type of promoters for the expression of the foreign gene, which was constructed from promoter P.sub.2 of E. coli ribosomal RNA operon and some regulatory sequences of E. coli las operon. The invention further relates to a method for the construction of the above vectors. The method is characterized by deleting most part of the structurgenes of E. coli ribosomal RNA operon (rrn operon) built in a suitable vector, joining together the part of operon rrn comprising promoter P.sub.2 with the beginning part of the lac operon outside the regions -35 and -10, downstream of them so as to create a new NsiI cleavage site at the joining point of the sequences originating from rrn and lac operons, deleting the inner TGCA sequence-element of the newly created NsiI cleavage site and building the structurgene to be expressed between these newly created regulatory sequences.