Extended Data Fig. 2: Partial division phenotypes during depletion of FtsZ1 or FtsZ2.

a, H. volcanii ID56 (p.tna-ftsZ1) was cultured in Hv-Cab + 2 mM Trp, and then loaded into a microfluidics platform and cultured with a flow of Hv-Cab (without Trp) over 15 h (0.5 p.s.i) to deplete FtsZ1. Shown is one cell that was identified to divide (unilaterally), even after ~9 h of depletion, and then one cell exhibited a budding-like process (arrows). Scale bars, 2 μm. b, H. volcanii ID57 (p.tna-ftsZ2) was pre-cultured in Hv-Cab + 2 mM Trp, and then loaded into a microfluidics platform and cultured with a flow of Hv-Cab + 2 mM Trp for 3 h, followed by Hv-Cab (no Trp) for 10 h (2 p.s.i) to deplete FtsZ2. The zero timepoint represents the start of medium flow without Trp. During the early stage of depletion of FtsZ2, partial constrictions were sometimes observed, as seen in these two examples (i and ii), but these never completed division and the constriction eventually reversed over several hours (see arrows). Cells, however, retained some apparent ‘memory’ of the initial constriction often manifesting as a somewhat bilobed shape. The data shown is representative of at least two independent experiments. Scale bars, 2 μm.