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Timothy McDougald

Posts: 1030
Joined: Dec. 2006

(Permalink) Posted: July 16 2008,19:15   

This looks interesting
Control of segment number in vertebrate embryos:
The vertebrate body axis is subdivided into repeated segments, best exemplified by the vertebrae that derive from embryonic somites. The number of somites is precisely defined for any given species but varies widely from one species to another. To determine the mechanism controlling somite number, we have compared somitogenesis in zebrafish, chicken, mouse and corn snake embryos. Here we present evidence that in all of these species a similar 'clock-and-wavefront'1, 2, 3 mechanism operates to control somitogenesis; in all of them, somitogenesis is brought to an end through a process in which the presomitic mesoderm, having first increased in size, gradually shrinks until it is exhausted, terminating somite formation. In snake embryos, however, the segmentation clock rate is much faster relative to developmental rate than in other amniotes, leading to a greatly increased number of smaller-sized somites.

Edit to add the link goes to the abstract in Nature.

Church burning ebola boy

FTK: I Didn't answer your questions because it beats the hell out of me.

PaV: I suppose for me to be pried away from what I do to focus long and hard on that particular problem would take, quite honestly, hundreds of thousands of dollars to begin to pique my interest.

  1753 replies since July 16 2008,08:10 < Next Oldest | Next Newest >  

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