Ciliary Behavior and Signal Transmission in the Embryonic Nodes: A Computational Fluid Dynamics Model

Although externally the vertebrate body is bilaterally symmetric, the internal organs, such as heart, spleen, pancreas, and lungs, exhibit marked left-right (L-R) asymmetry in their patterning and positioning. This lateral asymmetry is conserved in all vertebrates, suggesting that it is of ancient origin and defects in the establishment or maintenance of L-R asymmetry can result in serious health defects [1]. The mechanism by which L-R asymmetry is first established is a major question in developmental biology. In recent years, work by a number of groups has demonstrated that a cilia-driven leftward flow (know as ‘nodal flow’) of extra-cellular fluid across the embryo node is required for initiation of the symmetry breakage during embryogenesis [2].