FIG 4.

Midcell localization of the lipid-anchoring and processing machinery in H. volcanii. (A) Snapshots of merged phase-contrast (gray) and fluorescein isothiocyanate (FITC; green) channels of cells expressing FtsZ1-msfGFP, ArtA-msfGFP, HvPssA-msfGFP, HvPssD-msfGFP, and soluble msfGFP. Cells were immobilized under 0.5% agarose pads prepared with CA medium. (B) Time-lapse images of cells growing inside a CellASIC microfluidic device. Images of merged phase-contrast (gray) and FITC (green) channels were taken every 5 min for 12 h. Blue arrowheads indicate cell division events, while red arrowheads label one example of a cell elongating only after the arrival of ArtA-msfGFP to the midcell. (C) Snapshot of SLG-msfGFP (red) midcell localization. (D) Phase-contrast images of H. volcanii cells under prolonged overexpression (24 h) of the SLG-msfGFP fusion. (E) H. volcanii cells reshape and elongate preferentially at the midcell during protoplast recovery. Cells were loaded into the microfluidic chamber, and the S-layer was chemically removed by the addition of 1 mg/ml proteinase K and recovered with fresh medium (t = 0 h). Yellow arrowheads indicate the cell area extended until cell division (green arrowhead). Scale bars = 5 μm.