Although many gene-inactivation technologies have been applied to bacterial genetics, the potential for using antisense technology has not been extensively explored. In the September 21
They used an adapted tetracycline-dependent (tet) regulatory system to drive the expression of small fragments of sheared DNA. Colonies were selected that grew in the absence of anhydrotetracycline but not when expression was induced. About 3% of colonies were growth-defective or lethal upon induction, and about a third of these contained single-ORF antisense constructs. This method allows easy isolation and maintenance of conditional growth-defective strains, and rapid identification of the relevant gene.