Mapping of fitness landscapes of WT and <i>rho</i>* cells using transposon-mutagenized libraries.

<p>(A) Procedure used to identify loci with significant fitness contributions. Transposon mutagenized libraries were constructed separately in the WT and <i>rho</i>* strains, and then grown in parallel under selective conditions and a reference condition. Genomic regions adjacent to transposons were then selectively amplified. The abundances of transposon insertions throughout the genome were compared between the condition of interest and the reference condition using a two-color microarray. (B) Selective conditions used; M9t/glucose was the reference condition in all cases. (C) Comparison of gene-wise median fitness scores (log₂ ratio of reference∶selected microarray signals) between WT and <i>rho</i>* cells under each condition. For reference, a similar comparison between the two biological replicates of each strain/condition pairing is also shown. Pearson correlations (r) are given between WT and <i>rho</i>* signals or between replicate experiments for isogenic cells, as appropriate.