Fluorescence induction of P. luminescens containing the different promoter-reporter gene fusions after growth in G. mellonella. P. luminescens TT01 transformants carrying plasmid pBR-Cherry with the promoters of the genes indicated were grown in complex medium, and in vivo, in G. mellonella larvae. Last instar larvae were infected with approximately 10,000 cells, and after 48–72 h the larvae were bled. The fluorescence of the bacteria present in the hemolymph was analyzed by microscopy, and compared to the fluorescence of cells incubated for an equal time in complex medium. Induced: cells grown in G. mellonella; non-induced: cells grown in complex medium. A - no fluorescence under non-induced conditions, fluorescence under induced conditions; B - fluorescence under non-induced conditions, but higher fluorescence under induced conditions; C - equal numbers of bright fluorescent cells under non-inducing and inducing conditions, but additional cells with low fluorescence intensity under inducing conditions;D - fluorescence was equal under non-inducing and inducing conditions; E - bright fluorescence under non-inducing conditions, and low fluorescence under inducing conditions; F - no fluorescence under non-inducing or inducing conditions. Strains carrying the indicated promoter-reporter gene fusions were grouped. The examples shown are underlined; the control promoters are shaded in grey. In the left panels, cells were observed through a fluorescence filter, in the right panels cells were observed with phase contrast.
Münch et al. BMC Genomics 2008 9:229 doi:10.1186/1471-2164-9-229