Fig. 4.

PDIM deficiency confers an in vitro growth advantage in M. tuberculosis H37Rv. (A and B) Thin-layer chromatographic analysis of PDIM biosynthesis. Bacteria were labeled with [¹⁴C]propionate, which preferentially labels PDIM (6), and cell wall lipids were extracted and separated by thin-layer chromatography. (A) M. tuberculosis strains. H37Rv, Guilhot lab (25) (lane 1); H37Rv, McKinney lab (12) (lane 2); rv2958c::Tn (12) (lane 3). (B) M. tuberculosis strains, McKinney lab (12). H37Rv (lane 1), H37Rv after subculture (lane 2), rv2958c::Tn (lane 3), rv0072::Tn (lane 4), rv0405::Tn (lane 5). (C) Independently derived subclones of PDIM-positive H37Rv (squares) and PDIM-negative H37Rv (circles) were grown in 7H9 broth with aeration at 37°C. Growth of the cultures was monitored by withdrawing aliquots and measuring the OD₆₀₀ at the indicated time points (plotted on the primary y axis). The (PDIM-positive OD₆₀₀)/(PDIM-negative OD₆₀₀) ratios at each time point are plotted on the secondary y axis (diamonds). Results are representative of three independent experiments.