ama, Author at the Node

ama

Posts by ama

PLM10: the Physics of Living Matter is coming of age

Posted by ama, on 27 September 2015

This week, Cambridge (UK) hosted the 10th Symposium on the Physics of Living Matter (PLM10) (http://www.plm-symposium.org/). For those of us who were at PLM1, it is surprising to see that ...

In time of revision: of Wingless and morphogens

Posted by ama, on 27 December 2013

In time of revision: of Wingless and morphogens Alfonso Martinez Arias The recent publication of the important work of C. Alexandre, LA. Baena and JP. Vincent on the molecular requirements ...

A coming of age of Developmental Biology in Oxford: thou shall measure and think critically about your data

Posted by ama, on 7 July 2013

Alfonso Martinez Arias (http://bit.ly/14zBcke) An EMBO workshop organized by Alex Schier and James Briscoe, assembled a cast of young and seasoned biologists in Oxford to discuss progress and controversies on ...

Stem Cells in Developmental Biology: a debate at the BSDB

Posted by ama, on 29 March 2013

See below a posting from our website (http://amapress.gen.cam.ac.uk/) on the discussion that took place at the BSDB on whether to change or not the name of the society to include ...

What does a cell know and how does it know it (Just a thought on Dennis Bray’s Wetware, Yale University Press) Alfonso Martinez Arias (Dpt Genetics, University of Cambridge, Cambridge UK. ama11@hermes.cam.ac.uk)

Posted by ama, on 10 May 2012

It is a time of gene counting, mapping, function guessing in a narrow way: a gene for this or a gene for that. If one reads the indexes of journals ...

I have been looking for references to the notion that Wingless controls the growth of the wing through a long range mechanism, just in case I had missed something. Have found many but there is a good and succinct review that might be of interest to the ‘reader’. It is from Barry Thompson, one of the authorities on Wingless signaling in Drosophila, who has written about the role of Wingless as a morphogen. In a review on “Developmental control of cell growth and division in Drosophila’ (Current Opinion in Cell Biology 2010, 22:788–794) he is very explicit when summarizing the state of the field: “By comparing the development of the fly wing, leg and eye, it is clear that the pattern of expression of key ‘organising’ signals (such as BMP Dpp, the cytokine Unpaired, the Wnt Wingless and ligands for Notch) and the range over which they spread prefigures the size and shape of the tissue (Figure 2 ). The range of these signals increases during tissue growth and altering the range can cause a corresponding change in the size of the adult tissue it gives rise to” There are some surprising statements here but the reference to Wingless cannot be missed and summarizes the believe in the field. Incidentally and in case you cannot get the ms, Figure 2 highlights the DV stripe of Wingless that, according to the author (and most of the field) acts as the source of the morphogen. I am glad to hear that the ‘reader’ holds a different view and believes that the role of Wingless in growth is ‘mild’ -though this is debatable as the issue is not the degree of input but, as Alexandre et al make clear, the mechanism. I hope this is helpful.

by ama in In time of revision: of Wingless and morphogens on December 28, 2013

Thank you for the comment. The ‘reader’ appears to have a very different view of Wingless function during the development of the wing from that commonly held, which is good. However, if the only issue here was an underappreciated role of short range signalling and a solution to the ‘mild’ role of Wingless in the growth of the wing, there would not be a manuscript as the one just published and certainly not two news and views articles, raising some issues about it. The reason for the’noise’ and the ‘emotion’ in my post and in some of the Views in Nature, is that the published results clearly affect much in the field, in the notion of Morphogen and in the views of some people. There is little question that the work of Alexandre et al. addresses (and challenges) a widely held view that the function of Wingless in wing development is associated with its role as a Morphogen controlling, through long range signalling, growth and patterning. The manuscript contains more but this is one important issue that it addresses. I am pleased to hear that the ‘reader’, together with some of us, believes that the function of Wingless on growth is mild. These are the facts and one hopes that they will spread and that we start talking about Wingless and Wnt signalling in a different light. As for the short range function of Wingless, it was clear to some of us in 1994 (Couso, J.P., Bishop, S. Martinez Arias, A. (1994). The wingless signalling pathway and the patterning of the wing margin. Development. 120, 621-636) so I can only agree with the ‘reader’ that this function has been ‘underappreciated’. Perhaps the ‘reader’ can understand and forgive my emotion that something like that is noticed after almost 20 years of being overlooked in favour of a Morphogen view. One final thing, the work of Alexandre et al is about much more than this and one hopes that having established how Wingless works in the wing, people can move to the other issues that emerge from this work. As for the denticles in the tethered Wingless larvae, I agree that it is an interesting question and that the flies will soon be available to look into this and more. Once again, thank you for the comment

by ama in In time of revision: of Wingless and morphogens on December 27, 2013

ama