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LAPLAUD, V.

Publications and source records attributed to LAPLAUD, V..

2 recordsLinked to original sources

Dual role of the receptor kinase FERONIA in regulating tissue mechanics and growth

During morphogenesis, growing organisms adapt to internal and external mechanical stress. In plants, the receptor kinase FERONIA is involved in a broad range of responses to perturbations of the cell wall, but it is unclear which cues are sensed and how this sensing controls growth. Here, we addressed these questions in Marchantia vegetative propagules. We combined culture in microfluidic chips to quantify growth and mechanical properties of propagules, perturbations with osmotic treatments, characterisation of cell wall polysaccharides, and a mathematical model of cell wall expansion that incorporates sensing. We found that FERONIA independently regulates tissue mechanical properties and growth rates. We propose that the regulation of growth by the FERONIA pathway relies on both a positive feedback from elastic deformation of the wall and a negative feedback from wall expansion. Altogether, we expect our quantitative framework to be broadly relevant to the investigation of how mechanical cues guide development.

plant biology↗

Pinching the cortex of live cells reveals thickness instabilities caused by Myosin II motors

The cell cortex is a contractile actin meshwork, which determines cell shape and is essential for cell mechanics, migration and division. Because the cortical thickness is below optical resolution, it has been generally considered as a thin uniform two-dimensional layer. Using two mutually attracted magnetic beads, one inside the cell and the other in the extracellular medium, we pinch the cortex of dendritic cells and provide an accurate and time resolved measure of its thickness. Our observations draw a new picture of the cell cortex as a highly dynamic layer, harboring large fluctuations in its third dimension due to actomyosin contractility. We propose that the cortex dynamics might be responsible for the fast shape changing capacity of highly contractile cells that use amoeboid-like migration.

biophysics↗