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(1) Presentation(s)

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Lun. 28/03/2022 15:00 Andromede, Bâtiment 11, Etage 3

Séminaire
TLILI Sham (Institut de Biologie du Développement de Marseille)
Understanding the mechanics/genetics coupling during embryonic organoids symmetry breaking.

(Matière Molle)


Sommaire:

Embryonic tissues are striking examples of complex viscoelastic active fluids that self-organize into highly organized structures. Studying quantitatively the complex feedback-loop between tissue rheological properties, gene expression and morphogenetic flows requires a perturbative approach, which is challenging to adopt on a developing embryo, in particular in mammals that develop in utero. Mouse embryonic stem cells can self-organize in 3D embryonic organoids called Gastruloids sharing similarities with their in vivo counterparts. Recent studies have shown that they generate in few days structures similar genetically and morphologically with organs such as the neural tube or the heart.

The first major morphogenesis step for Gastruloids (early symmetry breaking) occurs between 72h and 96h after aggregation: they transform from a spherical cell aggregate with all cells expressing a rather homogeneous gene expression to an elongated tissue displaying an antero-posterior axis associated with strong cell differentiation heterogeneities.

In this talk, I will present in a first part our current understanding on the biophysical mechanism of Gastruloids early symmetry breaking, combining 3D live microscopy of collective cell flows and physical modeling of tissue phase separation due to heterogeneities in cell populations interfacial tensions. In a second part, I will present a method combining microfluidic aspirations of 3D cells aggregates with two-photon microscopy to force embryonic stem cells aggregates to flow through constrictions while imaging the tissue response at the cellular scale (i.e. cell deformations and rearrangements). I will finally discuss how this method could be extended to study spatial heterogeneities in tissue rheological properties emerging during embryonic patterning.


Pour plus d'informations, merci de contacter Merindol R.