L2/R2

The second anniversary of my request for help to position the four vortices Fleury claims is rapidly approaching and I was looking around for something relevant to make a celebration poster.

I opened The Mechanisms Underlying Primitive Streak Formation in the Chick Embryo, by Manli Chuai and Cornelis J. Weijer1 for inspiration and of course Fleury’s webpage with his english short presentation.

Chuai & Weijer propose a simple model fitting their observations.

reality-based.jpg

This is a rearrangement of elements from figure 1 (left panels) showing the transient vortices observed at the first stages of gastrulation at the epiblast level, bright field and epifluorescence, the marker being GFP expressed post-transfection and figure 3 (right panels) presenting a schema of their chemotactic model and the analogy with a hydrodynamic flow.

This is what Fleury describes as:

The usual picture of a development oriented in the antero-posterior direction is wrong. The recent dipolar description by Chuai, Weijer and co-workers is also wrong.

By saying so, he implies that the model don’t fit reality.
Maybe he failed to observe that the model proposed above include an area where Vx=Vy=0 at the center of Koller’s Sickle (KS)🙂

How Fleury’s model fit reality? One may think that it must be better.

Let’s see:

The left panels as previously described, the right panel from Fleury’s model, tilted to align the axis to the one of the microscope images, the lower one being a superposition with the actual data. Pretty much the same frame of Weijer’s et al. time-lapse movie as the one Fleury used to position the missing vortices two years ago [fr but the images are international].

That would place the hindlimbs, according to Fleury’s, behind the KS!

A larger picture with the missing vortices annotated L2/R2:

fantasy.jpg

not only “no L2/R2 – no hindlimbs” but also “if L2/R2, then hindlimbs behind the embryo!”

That doesn’t bother Fleury who prefers his model, coming out from the platonician space of forms, with the two invisibleimaginary vortices, instead of one quite realistic.

Make your mind. My preference goes to the one that stand reality check.

And if your name is Vincent Fleury and you are a theoretical physicist try to explain that.


1 Current Topics in Developmental Biology, Vol. 81 doi: 10.1016/S0070-2153(07)81004-0

7 Responses

  1. -the model you show here is a purely hydrodynamic model (vortex dipole inside a circle), you really understand nothing. Even wrong, at least, it’s an approach by hydrodynamic vortices, that should upset Mr Myers considerably, you should send him the paper for review.

    -sure, there is a flow oriented caudally in tetrapods, this model is wrong : there are cells flowing in the dark area, they flow caudally. They are just not stained in this assay, go to see the other fluorescent tracks on my web site, you will see that there is a flow oriented caudally, “below” the KRS. The vortex that revolves only in the posterior to anterior direction shown here is erroneous.

    -not only this model has Vx=Vy=0 at the intersection of the KRS and the anterio-posterior axis, but it has V(normal)=0 all along the perimeter; this means that the circle…stays for ever circular. It is not a moving boundary model, it is a flow inside a static shape.
    There is strictly no morphogenesis in this model, it is just a flow inside a fixed shape… wrong again.

    You really understand nothing.
    So pathetic.

    • A lot of pathetic people around you Dr Fleury. I’m glad to be in the same set as Chuai and Weijer and Myers.
      One have to chose his camp and reality based interpretations of the world are my favorite ones.

      So, the model proposed by Chuai & Weijer, an analogy which describes nicely the cells movement during the period where vortices are observed at the epiblast level, is restricted, it can’t describe more than this particular stage of development. So what? They don’t claim more than that.

      You are the one claiming more and unable to display it. You know you should bring proof of the existence of L2/R2 (and those should be vortices not caudal extension of the embryo) if you want to preserve some respectability on the subject. In a previous, deleted because redacted in french, comment you announced images of these vortices.
      Feel free to include a link to the URL of these images in your next comment (if it wasn’t a lie) ASAP.

      So, let me be pathetic😉

      PZ Myers comment concerns your flawed view of embryogenesis based in an imaginary model which remains without experimental/reality based substratum since your paper on Organogenesis in 2005. That’s what I call pathetic.

      I acknowledge that your model evolved since 2005, you expelled a lot of errors, but many persist and it is still unconnected with reality ; e.g. the equations you published concern a quite small subset of cells around the KS, without taking in account the great majority of cellular displacements, isn’t it? Without taking in account the available detailed description of cell movements. Isn’t it?

      C&W do much better.

    • Now, I almost fallen in this one.
      your equations are supposed to represent the consequences of motility of cells at the proximity of KS before the appearance of the PS, at this particular stage of gastrulation, not later.

      You, so eager of the spatio-temporal aspect of gastrulation, you don’t mix things, are you?

      So, L2/R2 not only imaginary, but also outside the embryo, Coco!😉

  2. faut arrêter tes saloperies mon Coco

    • For identification, according to the terms presented here:

      comments with names calling (e.g. nazi, censor) will usually be discarded, unless I decide otherwise to show the quality of the commenter; in this case along with the name, or nickname, or pseudonym will be published the IP and e-mail addresses of the commenter.

      this is a comment from:
      The info initially posted here was deleted to conform with WordPress.com’s Terms of Service. It is available via e-mail if you have a good reason to want it. Try to convince me.
      Or check here, you will find what’s necessary to contact Vincent Fleury and ask him what comments he endorses.

      I’ll change the terms in the about section as well.

  3. >>Feel free to include a link to the URL of these images in your next comment (if it wasn’t a lie) ASAP

    sure :

    http://www.msc.univ-paris-diderot.fr/~vincent/englishEnresume3.htm

    you will find plenty of it

    you understand truly nothing.

    “caudal extensions of the embryo”

    how do you think the embryo extends?

    Have a look at the model you show here : no extension whatsoever, and the velocities all along the border, are completely wrong way. it can’t be worse, just look : the velocities along the circle, in the model, are at 90° to the real case, that certainly fit’s nicely reality.

    I have to go for more serious things, you are pathetic, indeed.

    The others are not, they do research, one has a right to be wrong, in research, it is a cooperative effort, I do not blame them.

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