Handling Editor: Patrick Tam
ABSTRACT
During Xenopus gastrulation, leading edge mesendoderm (LEM) advances animally as a wedge-shaped cell mass over the vegetally moving blastocoel roof (BCR). We show that close contact across the BCR-LEM interface correlates with attenuated net advance of the LEM, which is pulled forward by tip cells while the remaining LEM frequently separates from the BCR. Nevertheless, lamellipodia persist on the detached LEM surface. They attach to adjacent LEM cells and depend on PDGF-A, cell-surface fibronectin and cadherin. We argue that active cell motility on the LEM surface prevents adverse capillary effects in the liquid LEM tissue as it moves by being pulled. It counters tissue surface-tension effects with oriented cell movement and bulges the LEM surface out to keep it close to the curved BCR without attaching to it. Proximity to the BCR is necessary, in turn, for the maintenance and orientation of lamellipodia that permit mass cell movement with minimal substratum contact. Together with a similar process in epithelial invagination, vertical telescoping, the cell movement at the LEM surface defines a novel type of cell rearrangement: vertical shearing.
Footnotes
Competing interests
The authors declare no competing or financial interests.
Author contributions
Conceptualization: M.N., R.W.; Methodology: J.K., R.H., A.E., A.C., J.M., T.B.; Formal analysis: M.N., R.W.; Investigation: M.N., D.B., E.W.D.; Writing - original draft: R.W.; Writing - review & editing: M.N., D.B., E.W.D., R.H.; Supervision: R.W.; Funding acquisition: R.W.
Funding
Funding was provided to R.W. by the Canadian Institutes of Health Research (PJT-15614).
Supplementary information
Supplementary information available online at https://dev.biologists.org/lookup/doi/10.1242/dev.198960.supplemental
- Received November 28, 2020.
- Accepted February 24, 2021.
Log in using your username and password
Log in through your institution
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$30.00 .
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.
Article navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
The Node is looking for a new Community Manager!
If you're interested in science communication, publishing and the developmental biology community, we're hiring for a new Community Manager for our community site, the Node.
The position is an exciting opportunity to develop an already successful and well-known site, engaging with the academic, publishing and online communities. Find out more and how to apply.
Upcoming special issue: call for papers
The Immune System in Development and Regeneration
Guest editors: Florent Ginhoux and Paul Martin
Submission deadline: 1 September 2021
Publication: Spring 2022
The special issue welcomes Review articles as well as Research articles, and will be widely promoted online and at key global conferences.
The people behind the papers - Clément Dubois, Shivam Gupta, Andrew Mugler and Marie-Anne Félix
A new paper investigates the robustness of neuroblast migration in the C. elegans larva in the face of both genetic and environmental variation. In an interview, the paper's four authors tell us more about the story.
Development presents...
Our successful webinar series continues into 2021, with early-career researchers presenting their papers and a chance to virtually network with the developmental biology community afterwards. Every talk is recorded and since launching in August last year, the series has clocked up almost 10k views on YouTube.
Here, Swann Floc'hlay discusses her work modelling dorsal-ventral axis specification in the sea urchin embryo.
Save your spot at our next session:
14 April
Time: 17:00 BST
Chaired by: François Guillemot
12 May
Time: TBC
Chaired by: Paola Arlotta
Join our mailing list to receive news and updates on the series.