Scientists Discover Mechanism That Gives Shape to Life

First time accepted submitter mcswell writes "Daniël Noordermeer and Denis Duboule, two researchers at Ecole Polytechnique Fédérale de Lausanne and the University of Geneva claim to have discovered how vertebrae get built in sequence in embryos (and by extension, how ribs, arms and so forth wind up in the right place). The story is that the DNA strands contain a linear series of HOX genes, and that the strands slowly unwind over a period of two days, successively exposing each HOX gene, thereby allowing it to be transcribed to form the segments of the vertebra. Snakes, it seems, have a defect that causes the system not to shut down; eventually it 'runs out of steam.' The same process is said to apply in many invertebrates, including worms (presumably segmented worms) and insects."

It's in Science 'cuz now we can SEE it?

[enderwig]

A caveat as I write this critique, I have only read the linked article and the abstract of the original scientific article, not the full Science article.
Also, I'm a Ph.D. in Developmental Biology from 2000.

If unwinding the super-coiled DNA is considered the chronometer for embryonic segmentation, what makes the DNA unwind at such a specific time? I'm not sure how much new light is shed by this work. We've known for >20 years that transcription factors help "open" DNA for the transcription process. We've also known for >20 years that HOX genes in their clusters are the masters of structural differentiation. Put these two facts together and we can see it should be obvious that the HOX genes need to be "opened" sequentially.

  In the end, we are left with the still burning question of "What controls the HOX genes and their clusters?"

Re:HOTAIR?

[Samantha Wright]

Absurd names are common in molecular biology. Here [wikipedia.org] is the usual example.