Polarity and Morphogenesis

Cell polarity establishment is a fundamental process controlling functional specificity in many cell types. This polarity depends on a precise control of asymmetric distribution of organelles and molecules towards different compartments in the cell. Such process is frequently achieved by molecular motors moving along a cytoskeleton network.

In a Drosophila egg chamber, Staufen protein accumulates to the posterior of the oocyte. Staufen (red), nuclear membranes are stained in blue and the plasma membrane in green.

We focus on the establishment of the Drosophila oocyte polarity during oogenesis. The establishment of the polarity axis of the Drosophila embryo rely on a polarised transport of embryonic determinants, such as bicoid, oskar and gurken mRNAs, toward several cortical compartments within the oocyte, before fertilisation. The diversity of this transport and the imaging facility of this cell, make the Drosophila oocyte a very good model system to study the initiation and the maintenance of cell polarity. The Drosophila oocyte allows to combine cell-biological, genetic and molecular approaches.

We are investigating how the cytoskeleton, in particular the microtubule network, is organised in the oocyte and how it is associated with the polarised transport of organelles and molecules toward different cortical domains in the oocyte.

We are investigating regulatory processes controlling the specificity of the polarised transport. We are looking for the cytoskeleton motors involved in the transport of bicoid, oskar et gurken mRNAs respectively localised to the anterior, the posterior and the antero-dorsal oocyte cortex. We are also investigating regulatory processes controlling the transport specificity for a define cargo, the selection of the molecular motor and the definition of the route to follow along the cytoskeleton network.

Selection of Publications

Compagnon J, Gervais L, Roman MS, Chamot S, Guichet A.
Interplay between Rab5 and PtdIns(4,5)P2 controls early endocytosis in the Drosophila germline. J Cell Sci. 2009 Jan 1;122(Pt 1):25-35.
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Nicolas E, Chenouard N, Olivo-Marin JC, Guichet A.
A Dual Role for Actin and Microtubule Cytoskeleton in the Transport of Golgi Units from the Nurse Cells to the Oocyte Across Ring Canals. Mol Biol Cell. 2009 Jan;20(1):556-68.
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Gervais L, Claret S, Januschke J, Roth S, Guichet A.
PIP5K-dependent production of PIP2 sustains microtubule organization to establish polarized transport in the Drosophila oocyte. Development. 2008 Dec;135(23):3829-38.
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Januschke J, Nicolas E, Compagnon J, Formstecher E, Goud B, Guichet A.
Rab6 and the secretory pathway affect oocyte polarity in Drosophila. Development. 2007 Oct;134(19):3419-25.
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Januschke, J, Gervais, L.,.Gillet, L., Keryer, G., Bornens, M., Guichet A.
The Centrosome Nucleus complex directs the formation of two orthogonal microtubule polarized transport in the Drosophila oocyte. Development. 2006 Jan;133(1):129-39.
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Last modified 03/14/2011

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