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Symmetry Breaking in a Model for Nodal Cilia

Brokaw, Charles J. (2005) Symmetry Breaking in a Model for Nodal Cilia. In: ISIS: International Symposium on Interdisciplinary Science, Natchitoches, LA, 6-8 October 2004. American Institute of Physics Conference Proceedings. No.755. American Institute of Physics , Melville, NY, pp. 107-116. ISBN 0-7354-0240-X.

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Nodal cilia are very short cilia found in the embryonic node on the ventral surface of early mammalian embryos. They create a right to left fluid flow that is responsible for determining the normal asymmetry of the internal organs of the mammalian body. To do this, the distal end of the cilium must circle in a counterclockwise sense. Computer simulations with 3-dimensional models of flagella allow examination of 3-dimensional movements such as those of nodal cilia. 3-dimensional circling motions of short cilia can be achieved with velocity controlled models, in which dynein activity is regulated by sliding velocity. If dyneins on one outer doublet are controlled by the sliding velocity experienced by that doublet, the system is symmetric, and the 3-dimensional models can show either clockwise or counterclockwise circling. My computer simulations have examined two possible symmetry breaking mechanisms: 1) dyneins on doublet N are regulated by a mixture of the sliding velocities experienced by doublets N and N+1 (numbered in a clockwise direction, looking from the base). or 2) symmetry is broken by an off-axis force that produces a right-handed twist of the axoneme, consistent with observations that some dyneins can rotate their substrate microtubules in a clockwise direction.

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Additional Information:©2005 American Institute of Physics. Issue Date: March 31, 2005.
Subject Keywords:cellular biophysics, computer aided analysis
Series Name:American Institute of Physics Conference Proceedings
Issue or Number:755
Record Number:CaltechAUTHORS:BROaipcp05
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9868
Deposited By: Archive Administrator
Deposited On:25 Mar 2008
Last Modified:03 Oct 2019 00:04

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