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. 2024 Jan 31;12:RP86577. doi: 10.7554/eLife.86577

Figure 6. The single-particle dynamics of BacA change over the course of the cell cycle.

(A) Representative heat maps showing the sum of single-particle positions observed in live-cell single-particle localization microscopy studies of a swimmer, stalked, and budding cell producing BacA-YFP (EC61) or a mutant cell producing the polymerization-deficient BacAF130R-YFP variant (MO78). Insets show the corresponding bright-field images. Bars: 1 µm. (B) Mean-squared displacement (MSD) analysis of the mobility of BacA-YFP in wild-type swimmer (n=100), stalked (n=105), and budding (n=101) cells (EC61). Cells (n=110) producing the BacAF130R-YFP were analyzed as a control (MO78). Error bars indicate the standard deviation. (C) Bubble plots showing the proportions of mobile and immobile particles (size of the bubbles) and the corresponding average diffusion constants (y-axis) in the cells analyzed in panel B.

Figure 6.

Figure 6—figure supplement 1. Single-particle tracking analysis of BacA-YFP.

Figure 6—figure supplement 1.

The images show the sums of all single-molecule tracks obtained for representative single H. neptunium swimmer, stalked and budding cell producing BacA-YFP (EC61) or for a mutant cell producing the polymerization-deficient BacAF130R-YFP variant (MO78). Cell outlines are indicated by white lines. Insets show the corresponding bright-field images. Bars: 1 µm.
Figure 6—figure supplement 2. Single-particle tracking analysis of BacA-YFP mobility.

Figure 6—figure supplement 2.

Shown is a Gaussian mixture model (GMM) analysis of the mobility of the BacA‐YFP variants plotted in Figure 5C. The distributions of the frame‐to‐frame displacements in both x and y direction from single‐particle tracking experiments were fitted to a two‐component Gaussian function (sum in black), assuming a fast‐diffusing mobile (dotted blue lines) and a slow‐diffusing (dotted red lines) population.
Figure 6—video 1. Tracking of single BacA-YFP particles in representative cells at different stages of the cell cycle.
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Shown are stream acquisitions (20 ms intervals) of H. neptunium cells producing wild-type BacA-YFP (EC61) or the polymerization-deficient BacAF130R-YFP variant (MO78) in place of the native BacA protein at different developmental stages. Bar: 1 µm.