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Updated: Jun 27, 2026

Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods
Published on: April 23, 2018
Evolution of leftward flow
Martin Blum1, Thomas Weber, Tina Beyer
1University of Hohenheim, Institute of Zoology, Stuttgart, Germany. mblum@uni-hohenheim.de
Abstract:
The asymmetric Nodal signaling cascade as a prerequisite for asymmetric body plan specification is conserved among deuterostomes. In this review we argue that symmetry breakage by cilia-driven leftward flow presents an ancestral character of vertebrates, likely the chordate phylum and maybe all deuterostomes. In vertebrates, leftward flow occurs in a transient structure, a monociliated epithelium, which is derived from superficial mesoderm and localizes to the archenteron roof during gastrulation. The chick as an example for the highly derived birds lacks superficial mesoderm and flow. This loss should be secondary, as flow is present from fish and amphibians to mammals.
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