|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 25 August 2004
doi: 10.1242/dev.01351
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK
2 Howard Hughes Medical Institute, Columbia University College of Physicians and
Surgeons, 701 West 168th Street, New York, NY 10032, USA
* Author for correspondence (e-mail: pal{at}mrc-lmb.cam.ac.uk)
Accepted 14 July 2004
The integument of the Drosophila adult abdomen bears oriented hairs and bristles that indicate the planar polarity of the epidermal cells. We study four polarity genes, frizzled (fz), prickle (pk), Van gogh/strabismus (Vang/stbm) and starry night/flamingo (stan/fmi), and note what happens when these genes are either removed or overexpressed in clones of cells. The edges of the clones are interfaces between cells that carry different amounts of gene products, interfaces that can cause reversals of planar polarity in the clone and wild-type cells outside them. To explain, we present a model that builds on our earlier picture of a gradient of X, the vector of which specifies planar polarity and depends on two cadherin proteins, Dachsous and Fat. We conjecture that the X gradient is read out, cell by cell, as a scalar value of Fz activity, and that Pk acts in this process, possibly to determine the sign of the Fz activity gradient.
We discuss evidence that cells can compare their scalar readout of the level of X with that of their neighbours and can set their own readout towards an average of those. This averaging, when it occurs near the edges of clones, changes the scalar response of cells inside and outside the clones, leading to new vectors that change polarity. The results argue that Stan must be present in both cells being compared and acts as a conduit between them for the transfer of information. And also that Vang assists in the receipt of this information. The comparison between neighbours is crucial, because it gives the vector that orients hairs – these point towards the neighbour cell that has the lowest level of Fz activity.
Recently, it has been shown that, for a limited period shortly before hair outgrowth in the wing, the four proteins we study, as well as others, become asymmetrically localised in the cell membrane, and this process is thought to be instrumental in the acquisition of cell polarity. However, some results do not fit with this view – we suggest that these localisations may be more a consequence than a cause of planar polarity.
Key words: frizzled, Van gogh, starry night, prickle
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  T. Bando, T. Mito, Y. Maeda, T. Nakamura, F. Ito, T. Watanabe, H. Ohuchi, and S. Noji Regulation of leg size and shape by the Dachsous/Fat signalling pathway during regeneration Development, July 1, 2009; 136(13): 2235 - 2245. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Shi, S. M. Peyrot, E. Munro, and M. Levine FGF3 in the floor plate directs notochord convergent extension in the Ciona tadpole Development, January 1, 2009; 136(1): 23 - 28. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Ma, K. Amonlirdviman, R. L. Raffard, A. Abate, C. J. Tomlin, and J. D. Axelrod Cell packing influences planar cell polarity signaling PNAS, December 2, 2008; 105(48): 18800 - 18805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Strutt and S. J. Warrington Planar polarity genes in the Drosophila wing regulate the localisation of the FH3-domain protein Multiple Wing Hairs to control the site of hair production Development, September 15, 2008; 135(18): 3103 - 3111. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Feng and K. D. Irvine Fat and Expanded act in parallel to regulate growth through Warts PNAS, December 18, 2007; 104(51): 20362 - 20367. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Wang and J. Nathans Tissue/planar cell polarity in vertebrates: new insights and new questions Development, February 15, 2007; 134(4): 647 - 658. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Wang, T. Badea, and J. Nathans Order from disorder: Self-organization in mammalian hair patterning PNAS, December 26, 2006; 103(52): 19800 - 19805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Casal, P. A. Lawrence, and G. Struhl Two separate molecular systems, Dachsous/Fat and Starry night/Frizzled, act independently to confer planar cell polarity. Development, November 1, 2006; 133(22): 4561 - 4572. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Blair, A. Tomlinson, H. Pham, K. C. Gunsalus, M. L. Goldberg, and F. A. Laski Twinstar, the Drosophila homolog of cofilin/ADF, is required for planar cell polarity patterning Development, May 1, 2006; 133(9): 1789 - 1797. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Wang, N. Guo, and J. Nathans The role of Frizzled3 and Frizzled6 in neural tube closure and in the planar polarity of inner-ear sensory hair cells. J. Neurosci., February 22, 2006; 26(8): 2147 - 2156. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Amonlirdviman, N. A. Khare, D. R. P. Tree, W.-S. Chen, J. D. Axelrod, and C. J. Tomlin Mathematical Modeling of Planar Cell Polarity to Understand Domineering Nonautonomy Science, January 21, 2005; 307(5708): 423 - 426. [Abstract] [Full Text] [PDF]
|
|
