Biophysical Society Thematic Meeting

Mechanobiology of Disease

Thursday Speaker Abstracts

Biomechanical Control of Tissue Morphogenesis

Thomas Lecuit

Insitut de Biologie du Développement de Marseille, Marseille, France.

Epithelial tissues exhibit a remarkable dual property of robustness and fluidity. This operates on

different time scales and relies on unique mechanical properties of the cell cortex and on

adhesive interactions between cells. We seek to understand the fundamental molecular

mechanisms responsible for this property.

To that end we develop a range of approaches, from the genetic and pharmacological

perturbations of molecular components, the quantitative imaging of proteins using a variety of

photonic methods, probing of the physical properties of cells within intact tissues, and

computational modelling of morphogenesis at different scales (molecular to tissue scales).

I will present our recent progress in understanding how polarization of cortical tension underlies

the dynamic cell shape changes and tissue morphogenesis. I will report recent findings

delineating a novel GPCR signalling pathway responsible for the spatial regulation of cortical

tension by the Rho1 pathway during tissue invagination and tissue extension. Evidence of

mechanical feedbacks will be reported and discussed.

Muscle Specification in the Zebrafish Myotome

Timothy Saunders

Mechanobiology Institute, National University of Singapore, Singapore.

One of the central questions in developmental biology is how cells from an equivalent group

commit to different cell fate. Here, we explore cell fate differentiation in the developing

zebrafish myotome, where different muscle types (muscle pioneers, slow muscle fibers and fast

muscle fibers) are differentiated from adaxial cells. Sonic hedgehog (SHH), BMP and FGF have

all been proposed as signaling molecules playing a role in specifying muscle cell fate.

Combining live imaging of zebrafish myogenesis with cell tracking and lineage analysis, we

develop four-dimensional maps of the developing somite. Using these maps, we explore the

specification and migration of different muscle fibres. In particular, we focus on the interaction

between different cell types and how this effects the timing of cell specification. Our results

suggest that robust cell fate specification in the myotome is effectively dependent on

biomechanical processes as well as chemical signaling.