Bidirectional transport model of morphogen gradient formation via cytonemes
File(s)cytonemeR1.pdf (987.76 KB)
Accepted version
Author(s)
Bressloff, Paul C
Kim, Hyunjoong
Type
Journal Article
Abstract
Morphogen protein gradients play an important role in the spatial regulation of patterning during embryonic development. The most commonly accepted mechanism for gradient formation is diffusion from a source combined with degradation. Recently, there has been growing interest in an alternative mechanism, which is based on the direct delivery of morphogens along thin, actin-rich cellular extensions known as cytonemes. In this paper, we develop a bidirectional motor transport model for the flux of morphogens along cytonemes, linking a source cell to a one-dimensional array of target cells. By solving the steady-state transport equations, we show how a morphogen gradient can be established, and explore how the mean velocity of the motors affects properties of the morphogen gradient such as accumulation time and robustness. In particular, our analysis suggests that in order to achieve robustness with respect to changes in the rate of synthesis of morphogen, the mean velocity has to be negative, that is, retrograde flow or treadmilling dominates. Thus the potential targeting precision of cytonemes comes at an energy cost. We then study the effects of non-uniformly allocating morphogens to the various cytonemes projecting from a source cell. This competition for resources provides a potential regulatory control mechanism not available in diffusion-based models.
Date Issued
2018-03
Date Acceptance
2018-01-09
Citation
Physical Biology, 2018, 15 (2)
ISSN
1478-3967
Publisher
IOP Publishing
Journal / Book Title
Physical Biology
Volume
15
Issue
2
Copyright Statement
Copyright © 2018 IOP Publishing Ltd. This is an author-created, un-copyedited version of an article published in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/1478-3975/aaa64c
Identifier
http://dx.doi.org/10.1088/1478-3975/aaa64c
Publication Status
Published
Article Number
026010
Date Publish Online
2018-02-08