Document Type
Article
Publication Date
3-13-2018
Abstract
Indirect evidence suggests that blastopore closure during gastrulation of anamniotes, including amphibians such as Xenopus laevis, depends on circumblastoporal convergence forces generated by the marginal zone (MZ), but direct evidence is lacking. We show that explanted MZs generate tensile convergence forces up to 1.5 mN during gastrulation and over 4 mN thereafter. These forces are generated by convergent thickening (CT) until the midgastrula and increasingly by convergent extension (CE) thereafter. Explants from ventralized embryos, which lack tissues expressing CE but close their blastopores, produce up to 2 mN of tensile force, showing that CT alone generates forces sufficient to close the blastopore. Uniaxial tensile stress relaxation assays show stiffening of mesodermal and ectodermal tissues around the onset of neurulation, potentially enhancing long-range transmission of convergence forces. These results illuminate the mechanobiology of early vertebrate morphogenic mechanisms, aid interpretation of phenotypes, and give insight into the evolution of blastopore closure mechanisms. © Shook et al.
Recommended Citation
Shook, David R.; Kasprowicz, MD, Eric; Davidson, Lance A.; and Keller, Raymond, "Large, long range tensile forces drive convergence during" (2018). Division of Internal Medicine Faculty Papers & Presentations. Paper 32.
https://jdc.jefferson.edu/internalfp/32
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
PubMed ID
29533180
Language
English
Comments
This article has been peer reviewed. It is the author’s final published version in eLife, Volume 7, March 2018, Article number e26944.
The published version is available at https://doi.org/10.7554/eLife.26944 . Copyright © Shook et al.