Publisher's Synopsis
A vector for transformation into a host cell is described comprising a toxic gene encoding a product that is lethal to the host cell, wherein the toxic gene comprises: an essential sequence region whose integrity is necessary in order for the encoded toxic gene product to be lethal to the host cell; an inessential sequence region whose integrity is not essential in order for the encoded toxic gene product to be lethal to the host cell; a regulatory sequence inserted in-frame into the inessential sequence region; and a cloning site within the essential sequence region for insertion of a nucleic acid sequence, wherein the regulatory sequence and the cloning site are positioned so as to allow the regulatory sequence to be operably linked to a nucleic acid sequence when the nucleic acid sequence is inserted into the cloning site.
