The essential gene sets at 30°C. (A) The Circos program was used to map transposon insertion sites across the genome, with a histogram depicting the number of reads per TA site in purple. The innermost blue rings depict the locations of non-essential genes for which a fitness cost was not observed, while the outermost red ring depicts those genes identified as essential. The middle green ring represents those genes that were found to be domain essential. (B) Venn diagram comparing our essential gene list to Chaudhuri et al. and Valentino et al [29,33]. There is extensive overlap between the three studies. 211 genes were classified as essential in all three works. These represent a core set of genes required for cell growth regardless of experimental and analytical variations.