Section: New Results
Connecting trajectories in TIRF images of rodshaped bacteria
Participants : Yunjiao Lu, Charles Kervrann.
In this work, we investigate the role of MreB protein involved in the cell wall construction in rodshaped bacteria Bacillus. Previous work concerning the quantification of dynamics of MreB is performed from 2D TIRFM image sequences, ignoring the curvature of the rodshaped cell wall and the thickness of TIRFM plane. To evaluate the effect of these approximations, we have developed a simulator to generate the trajectories on the surface of the cylinder. We assume that trajectories are modeled as:
where $b\left(X\right)$ is the drift tangent to the surface, $W$ is a white noise, and $\sigma \left(X\right)=\frac{1}{2}B\left(X\right)B{\left(X\right)}^{T}$ is the diffusion tensor assumed to be isotropic. In our approach, the drift and diffusion tensor on the surface and on the projected plane are estimated respectively. Moreover, we propose to extrapolate the drift and diffusion tensor to the hidden region, to reconnect the segments we observe in the visible region, and then, to recover the entire trajectory on the surface of the cylinder in 3D (see Fig. 8).
Collaborators: Alain Trubuil and Pierre Hodara (INRA UR MAIAGE, JouyenJosas),
Rut CarbllidoLópez and Cyrille Billaudeau (INRA, UR MICALIS, JouyenJosas).
