EXPRESSION OF LUXCD-E IN ANABAENA SP CAN REPLACE THE USE OF EXOGENOUSALDEHYDE FOR IN-VIVO LOCALIZATION OF TRANSCRIPTION BY LUXAB

The genes luxCDABE from four luminescent bacteria suffice for light pr oduction in Escherichia coli [Meighen, Microbiol, Rev, 55 (1991) 123-1 42]. We have inserted these gene clusters between inverted polylinkers , and placed the resulting cassettes as reporters within derivatives o f transposon Tn5. Anabaena sp. strain PCC 7120 was mutagenized with th ese transposons. The luminescence of al but the most highly self-lumin escent resulting derivatives of Anabaena sp. was strongly dependent on exogenously added aldehyde. Thus, luminescence based on luxCDABE is m ultiplicatively limited by production of luciferase and aldehyde. No t oxicity was observed over protracted periods of luminescence. By delet ion, new cassettes were derived in which only the aldehyde biosyntheti c genes, luxCD-E, remained intact. Transcription was localized at the single-cell level in strains of cyanobacteria bearing constitutively e xpressed Xenorhabdus luminescens luxCD-E on a plasmid and relatively w eakly expressed, developmentally regulated luxAB from Vibrio spp. in t he chromosome. The developmentally critical gene, hetR, was thereby sh own to remain active in mature heterocysts.