Abstract
Deformations of cell sheets are ubiquitous in early animal development, often arising from a complex and poorly understood interplay of cell shape changes, division, and migration. Here, we explore perhaps the simplest example of cell sheet folding: the "inversion" process of the algal genus Volvox, during which spherical embryos turn themselves inside out through a process hypothesized to arise from cell shape changes alone. We use light sheet microscopy to obtain the first three-dimensional visualizations of inversion invivo, and develop the first theory of this process, in which cell shape changes appear as local variations of intrinsic curvature, contraction and stretching of an elastic shell. Our results support a scenario in which these active processes function in a defined spatiotemporal manner to enable inversion.
Highlights
Lewis Wolpert’s comment, “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” [1], emphasizes the central role of cell sheet folding in developmental biology
One of the common themes accompanying the bending and stretching of cell sheets during invaginations is a set of cell shape changes, in particular transitions from columnar to wedge shapes [5]
Cell sheet deformations in animal model organisms frequently involve cell division, migration, and intercalation that obscure the specific role of shape changes
Summary
Lewis Wolpert’s comment, “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” [1], emphasizes the central role of cell sheet folding in developmental biology. Similar cell shape changes and reorganization of cytoplasmic bridges have been reported for type-B inversion [13]. Other cell shape changes specific to type-B inversion occur in the anterior and posterior hemispheres [13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
