A mesoscopic level multi-scale approach to generate a complex polymer morphology

Unraveling the embryonic fate map through the mechanical signature of cells and their trajectories

10.21203/rs.3.rs-333921/v1 ◽

2021 ◽

Author(s):

David Pastor-Escuredo ◽

Benoit Lombardot ◽

Thierry Savy ◽

Adeline Adeline Boyreau ◽

Rene Doursat ◽

...

Keyword(s):

Deformation Rate ◽

Phenotypic Variability ◽

Early Developmental Stage ◽

Embryonic Cells ◽

Imaging Data ◽

Fate Map ◽

Cell Lineages ◽

Multi Scale ◽

Mesoscopic Level ◽

Cumulative Deformation

Abstract Digital cell lineages reconstructed from 3D+time imaging data of the developing zebrafish embryo are used to uncover mechanical cues and their role in morphogenesis. A continuous approximation of cell displacements obtained from cell lineages is used to assess tissue deformation during gastrulation. At this stage, embryonic tissues display multi-scale compressible fluid-like properties. The deformation rate at the mesoscopic level of the cell’s immediate surroundings appears noisy, in both space and time. The patterns identified by clustering the cells, according to the cumulative deformation rate along their trajectory throughout gastrulation, lead to a robust, ordered and coherent biomechanical map. The timing and amplitude of the biomechanical deformations provide a measurement of the phenotypic variability in small cohorts of specimens. We show that the biomechanical map matches the embryonic fate map of the zebrafish presumptive forebrain, in both wild type and Nodal pathway mutants (zoeptz57/tz57), where it reveals the biomechanical defects that lead to cyclopia.. The comparison of biomechanical patterns and the expression pattern of a transgenic reporter for the transcription factor goosecoid (gsc), supports the hypothesis that embryonic cells acquire, at an early developmental stage, a biomechanical signature that contributes to defining their fate.

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Polymer Morphology Revealed by Staining Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098204 ◽

1981 ◽

Vol 39 ◽

pp. 340-341

Author(s):

A. C. Reimschuessel ◽

V. Kramer

Keyword(s):

Polymer Melt ◽

Nylon 6 ◽

Morphological Features ◽

Negative Staining ◽

Polymer Morphology ◽

Crystallizable Polymer ◽

Staining Techniques ◽

Long Chain

Staining techniques can be used for either the identification of different polymers or for the differentiation of specific morphological domains within a given polymer. To reveal morphological features in nylon 6, we choose a technique based upon diffusion of the staining agent into accessible regions of the polymer.When a crystallizable polymer - such as nylon 6 - is cooled from the melt, lamellae form by chainfolding of the crystallizing long chain macromolecules. The regions between adjacent lamellae represent the less ordered amorphous domains into which stain can diffuse. In this process the lamellae will be “outlined” by the dense stain, giving rise to contrast comparable to that obtained by “negative” staining techniques.If the cooling of the polymer melt proceeds relatively slowly - as in molding operations - the lamellae are usually arranged in a radial manner. This morphology is referred to as spherulitic.

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