Fig 3. Characterization of functional broad-host range replicons in the honey bee gut symbiont S. alvi.

(a) Broad-host range plasmids have different copy numbers in S. alvi. Box plots show median values of plasmid copy numbers obtained by qPCR from 3 independent experiments with 5 biological replicates each (total n = 15). Median copy numbers are indicated above the corresponding box plots. (b) The difference in plasmid copy number results in different protein expression levels in S. alvi. Graph shows mean of GFP fluorescence ± standard deviations of 5 biological replicates. Each replicate represents the average fluorescence of at least 9,000 cells measured by flow cytometry. Plasmids used for panels a and b in S. alvi were pAC08, pAC14, pAC13, and pAC12, carrying the RSF1010, pTF-FC2, pVS1, and pBBR1 origins of replication, respectively. (c) Some replicons are compatible and can be cotransformed in S. alvi. Matrix table indicates compatible (green boxes with check mark) and incompatible (red boxes with cross mark) replicons. Vectors were found compatible upon their successful cotransformation by electroporation in S. alvi. The data underlying this Figure can be found in the S1 Data file, sheets “Fig 3A” and “Fig 3B”.