Section: New Results

Detection and tracking of astral microtubules at the cell cortex

Participants : Thierry Pécot, Charles Kervrann, Geoffrey Dieffenbach.

In this study, we are interested in the influence of the mechanical properties of astral microtubules in the centering mechanisms of the mitotic spindle, giving it a robust positioning. In their previous studies, the CeDRE group (IGDR Rennes) identified two subpopulations of astral microtubules that either push or pull the cell cortex. To better understand these mechanisms, image sequences are acquired at the cortex level where extremities of astral microtubules come to exert forces. In order to characterize the two subpopulations of astral microtubules during the mitosis in the unicellular embryos of C. Elegans, life span, that is the period during which the microtubule is touching the cell cortex, for every single microtubule has to be measured. A short life span corresponds to a pulling force while a longer life span corresponds to a pushing force. Detecting and tracking microtubules at the cell cortex has to be done to collect these measures. As the signal-to-noise ratio is low, a denoising step is needed to detect the microtubule extremities. Several detection methods were tested but we need to further investigate this step to find the most suited methods for this particular application. Finally, the U-track algorithm [42] is applied to track the microtubules extremities to measure their life span.

Collaborators: Jacques Pécréaux (CeDRE group, IGDR Rennes, CNRS UMR 6290)

                          Hélène Bouvrais (CeDRE group, IGDR Rennes, CNRS UMR 6290)

Figure 9.

Microtubule extremities detection and tracking in fluorescence microscopy

(embryo of C. Elegans, IGDR - Institute of Genetics and Developmental biology of Rennes, CNRS UMR 6290).