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ZFIN ID: ZDB-PUB-190808-16
Spatio-temporal characterization of dynamic epithelial filopodia during zebrafish epiboly
Rutherford, N.E., Wong, A.H., Bruce, A.E.E.
Date: 2019
Source: Developmental dynamics : an official publication of the American Association of Anatomists   248(10): 997-1008 (Journal)
Registered Authors: Bruce, Ashley
Keywords: cellular protrusion, enveloping layer, gastrulation, morphogenesis
MeSH Terms:
  • Actins/metabolism
  • Animals
  • Blastoderm/cytology
  • Embryo, Nonmammalian
  • Epithelium/ultrastructure*
  • Gastrulation
  • Pseudopodia/ultrastructure*
  • Spatio-Temporal Analysis*
  • Zebrafish
PubMed: 31390119 Full text @ Dev. Dyn.
During zebrafish epiboly, the embryonic cell mass, or blastoderm, spreads to enclose the yolk cell. The blastoderm consists of an outer epithelial sheet, the enveloping layer (EVL), and underlying deep cells. Studies have provided insights into the mechanisms of EVL and deep cell epiboly, but little is known about the interactions between the two cell layers and what role they may play during epiboly.
We used live imaging to examine EVL basal protrusions. We identified them as filopodia based on f-actin content and localization of fluorescently tagged filopodial markers. A spatio-temporal analysis revealed that the largest number of EVL filopodia were present during early epiboly at the animal pole. In functional studies, expression of a constitutively active actin bundling protein resulted in increased filopodial length and delayed gastrulation.
We identified protrusions on the basal surface of enveloping layer cells as filopodia and showed that they are present throughout the EVL during epiboly. The largest number of filopodia were at the animal pole during early epiboly, which is when and where deep cell radial intercalations are greatest. These findings suggest that EVL filopodia may function during epiboly to promote deep cell rearrangements during epiboly initiation. This article is protected by copyright. All rights reserved.