Mechanics and Variability of Cell Sheet Folding in the Embryonic Inversion of $Volvox$

TL;DR

This study investigates how the green alga Volvox's embryo undergoes inversion, focusing on the mechanics and variability of cell sheet folding, combining experimental imaging and theoretical analysis to understand shape variability and regulation.

Contribution

It provides a detailed analysis of the mechanics and regulation of cell sheet folding during Volvox inversion, highlighting how variability arises from geometry, mechanics, and active regulation.

Findings

Quantified variability in Volvox inversion process.

Analyzed mechanical contributions to shape variability.

Identified role of active regulation in morphogenesis.

Abstract

Many embryonic deformations during development are the global result of local cell shape changes and other local active cell sheet deformations. Morphogenesis does not only therefore rely on the ability of the tissue to produce these active deformations, but also on the ability to regulate them in such a way as to overcome the intrinsic variability of and geometric constraints on the tissue. Here, we explore the interplay of regulation and variability in the green alga $Volvox$, whose spherical embryos turn themselves inside out to enable motility. Through a combination of light sheet microscopy and theoretical analysis, we quantify the variability of this inversion and analyse its mechanics in detail to show how shape variability arises from a combination of geometry, mechanics, and active regulation.