Mechanisms of asymmetric trafficking
Asymmetric cell division is the process by which one cell divides into two daughter cells that have different fates. Asymmetric division is the hallmark of stem cells, in which one daughter cell specialises to perform a specific function in the organism, while the other becomes another stem cell that keeps the ability to divide.
We are interested in understanding how cell fate determinants segregate asymmetrically during asymmetric division. In particular, we focus on finding the molecular and physical mechanisms by which polarity cues are “written” onto the microtubule cytoskeleton during asymmetric division and how, in turn, these polarity signals are “read” by molecular motors to carry endosomes containing fate determinants into only one daughter cell. Our approach is highly pluridisciplinary, from reconstituted cytoskeleton systems in vitro, high-end quantitative imaging of trafficking in vivo during development, to analysis of morphological phenotypes in adult flies, relying on theoretical physics to bridge these different scales.
Our long term vision is capitalize on this work in Drosophila to restore asymmetric cell fate in situations where it has been lost in mammalian stem cells, such as during ageing or tumorigenesis.
Asymmetric division of a sensory organ precursor
cell where endosomes containing cell fate
determinants (green) are asymmetrically segregated
into only one daughter cell thanks to symmetry
breaking of the microtubule cytoskeleton (red).
Microtubule dynamics during development
of the notum epithelium in Drosophila.
Asymmetrically dividing sensory organ
precursors are labelled in red.
- Derivery E, Seum C, Daeden A, Loubéry S, Holtzer L, Jülicher F, Gonzalez-Gaitan M. (2015)
Polarized endosome dynamics by spindle asymmetry during asymmetric cell division.
Nature 528: (7581):280-5.
- Joseph Watson