Figure 2.

Exconjugants of pMPPla107 from populations 4 and 5 into an ancestral chromosomal background transfers resistance to the inhibitory agent. Given that strains 4B-500 and 5B-500 were known to display resistance against the inhibitory agent, we conjugated megaplasmids from these strains into an unevolved P. stutzeri background DBL388. We additionally used conjugations with the megaplasmid from 3B-500 as a sensitive (positive) control as we knew this evolved strain was still sensitive. While a megaplasmid from 3B-500 maintains sensitivity to the inhibitory agent in the DBL388 background, megaplasmids from 4B-400 and 5B-500 transfer resistance. All overlays were plated after 4 h of growth in KB and spotted with 10 µl of P. stutzeri filter-sterilized supernatants. All images are representative of three biological replicates. Raw image files can be found in electronic supplemental material at Figshare (doi:10.6084/m9.figshare.15072537.v3): DBL618 is electronic supplementary material, figure S1, DBL619 is electronic supplementary material, figure S2, DBL620 is electronic supplementary material, figure S3. (Online version in colour.)