Glycogen accumulation in wild type, csrA mutant, and complemented mutant strains of E. coli. Top Panel) MG1655[pBAD], TRMG1655[pBAD], TRMG1655[pBADcsrAEC], and TRMG1655[pBADcsrACJ] were spotted onto Kornberg agar supplemented with 2% glycerol and 0.002% L-arabinose and incubated at 37°C overnight. The following day, the strains were stained for glycogen accumulation by inverting over iodine crystals. Bottom Panel) Expression of his-tagged CsrAEC and CsrACJ in TRMG1655 was confirmed by western blot using anti-his primary antibodies. Presence (+) or absence (−) of inducible CsrAEC or CsrACJ in each strain is shown beneath the panels.